Cobra CX50 2014 Specifications

For parts orders contact your local dealer
To locate your closest Cobra dealer
log on to
www.cobramotorcycle.com
or call
(517) 437-9100
If you need technical assistance
contact your local dealer or call
the Cobra Technical Support Hotline at
(517) 437-9100
Cobra Moto, LLC
240 Uran Street
Hillsdale, Michigan 49242
DISCLAIMER OF WARRANTY
This motorcycle is sold “as is” with all faults, obvious or not. There are no warranties
expressed or implied, including any warranty of merchantability and warranty of fitness
for any particular purpose.
WARNING
THE COBRA CX50JR IS A COMPETITION MODEL ONLY AND IS NOT
MANUFACTURED FOR, NOR SHOULD IT BE USED ON PUBLIC STREETS, ROADS
OR HIGHWAYS.
THE USE OF THIS BIKE SHOULD BE LIMITED TO PARTICIPATION IN
SANCTIONED COMPETITION EVENTS UPON A CLOSED COURSE BY A
SUFFICIENTLY SKILLED RIDER AND SHOULD NOT BE USED FOR GENERAL
OFF-ROAD RECREATIONAL RIDING.
IMPROPER USE OF THIS MOTORCYCLE CAN CAUSE INJURY OR DEATH.
THIS BIKE IS INTENDED FOR EXPERIENCED RACERS ONLY AND NOT FOR
BEGINNERS.
IT IS YOUR RESPONSIBILITY AS THE OWNER OF THIS COBRA MOTORCYCLE
OR AS THE PARENT, OR LEGAL GUARDIAN OF THE OPERATOR, TO KEEP THIS
COBRA MOTORCYCLE IN PROPER OPERATING CONDITION.
THIS BIKE WAS DESIGNED FOR RIDERS THAT WEIGH LESS THAN 80 LBS WITH
FULL RIDING GEAR AND SHOULD NOT BE OPERATED BY RIDERS THAT WEIGH
MORE.
BE SURE THAT THE RIDER ALWAYS WEARS ADEQUATE SAFETY GEAR
EVERYTIME HE OR SHE RIDES THEIR COBRA MOTORCYCLE.
IMPORTANT SAFETY NOTICE
Failure to follow WARNING instructions could result in severe injury or death to
the machine operator, a bystander, or a person inspecting or repairing the
machine.
CAUTION:
A CAUTION indicates special precautions that must be taken to avoid damage to
the machine.
NOTE: A NOTE provides key information to make procedures easier or clearer.
MCCJ2014.0
Table of Contents
General Information .............................................................................................. 4
Specifications - General .................................................................................... 4
Optional Suspension Components .................................................................... 5
Specifications - Torque Values.......................................................................... 5
Break-In Procedure ........................................................................................... 6
Starting Procedure ............................................................................................ 7
Maintenance ......................................................................................................... 8
Tips ................................................................................................................... 8
Schedule ........................................................................................................... 9
Replacing Transmission / Clutch Lubricant ..................................................... 10
Proper Chain adjustment................................................................................. 11
Rear Brake Maintenance................................................................................. 11
Brake Bleeding Procedure .............................................................................. 13
Air Filter Cleaning ............................................................................................ 14
Fork Oil Replacement...................................................................................... 15
Cobra Frictional Drive (V3 CFD) ..................................................................... 16
Parts ................................................................................................................... 18
Parts – Airbox and Inlet System ...................................................................... 18
Parts – Bars and Controls ............................................................................... 19
Parts - Carburetor............................................................................................ 20
Parts – Coolant System................................................................................... 21
Parts – Electrical System ................................................................................ 22
Parts – Engine – Bottom End and Transmission ............................................. 23
Parts – Engine Clutch and Kicker .................................................................... 24
Parts – Engine – Top End ............................................................................... 26
Parts – Exhaust System .................................................................................. 27
Parts – Forks & Triple Clamps ........................................................................ 28
Parts – Forks – Leg Assembly – Brake Side ................................................... 29
Parts – Forks – Leg Assembly – Non-Brake Side ........................................... 30
Parts – Frame – Mounting Hardware I ............................................................ 31
Parts – Frame – Mounting Hardware II ........................................................... 32
Parts – Front Brakes ....................................................................................... 33
Parts – Front Wheel ........................................................................................ 34
2
Parts – Plastic & Seat...................................................................................... 35
Parts – Rear Brake .......................................................................................... 36
Parts – Rear Wheel ......................................................................................... 37
Parts – Shock .................................................................................................. 38
Parts – Shock - Inside ..................................................................................... 39
Parts – Swingarm Assembly ........................................................................... 40
Service ................................................................................................................ 41
Engine Service ................................................................................................ 41
Base Gasket Selection ................................................................................ 42
Engine Removal .......................................................................................... 44
Complete Engine Disassembly Procedure .................................................. 44
Top End Disassembly Procedure ................................................................ 45
Splitting the Cases ....................................................................................... 46
Engine Assembly ......................................................................................... 46
Clutch .............................................................................................................. 48
Ignition............................................................................................................. 52
Cooling System ............................................................................................... 54
Radiator fluid removal: ................................................................................. 54
Fuel & Air System............................................................................................ 57
Carburetor.................................................................................................... 57
Reeds .......................................................................................................... 59
Exhaust ........................................................................................................... 59
Wheels & Tires ................................................................................................ 59
Rear wheel pullers ....................................................................................... 60
Brakes ............................................................................................................. 60
Rear Shock ..................................................................................................... 62
Tuning ................................................................................................................. 63
Gearing ........................................................................................................... 66
Suspension ..................................................................................................... 67
Rear shock................................................................................................... 68
Front Forks .................................................................................................. 69
Carburetion ..................................................................................................... 69
Troubleshooting .................................................................................................. 73
Index ................................................................................................................... 75
3
General Information
Specifications - General
Items
Dimensions
Wheelbase
Wheel size
Seat height
Engine
Type
Cooling system
Coolant
Displacement
Bore and stroke
Ignition system
Spark plug
Gap
Ignition timing
Fuel type
Premix Oil type
Premix oil ratio after break-in
Carburetion
Slow (Pilot) Jet / Main Jet
Float Height
Transmission
Speed / Clutch
Final drive ratio
Chain
Transmission / clutch oil type
Quantity
Chassis
Front tire
Pressure
Rear tire
Pressure
Front fork
Fork oil type
Fork oil amount
Std settings
Rear Shock ( std settings)
CX50 JR
35.75” (908mm)
10” (254mm)
23.9” (607 mm)
2-stroke, single cylinder, reed valve
Liquid-cooled
50/50 antifreeze-coolant / distilled water
49.8 cc
39 mm x 41.7 mm
Electronic, analogic advance
Autolite - XS61 & 4261
0.023” – 0.025” (0.58 – 0.64 mm)
0.040” (1.0 mm) Before Top Dead Center (BTDC)
High octane pump gasoline
Bel-Ray H1-R
40:1 to 50:1
14 mm Dell’Orto
55 / 92
16mm + 0.5mm (0.63” + 0.020”)
Single / Cobra 3 shoe
14/37 T
420
Cobra Venom 3 Shoe Clutch Milk
235 – 350 ml (8 – 12oz)
2.50 – 10
15 psi minimum
2.75 – 10
15 psi min. (20 psi for hard pack or rocky conditions)
CARD 32mm USD Fully Adjustable w/ Smart Leg
2.5wt Bel-Ray Fork Oil
145 ml
Smart leg: 3out,Compression and rebound 1 1/2 out
Compression Low 7, High 7, No Rebound Adj.
4
Optional Suspension Components
Weight of Rider (lb)
Fork Spring
Shock Spring
Less than 38 (light)
KCCJ3218
(18 lb/in, 3.15 N/mm)
SCMUOH04 (275 lb/in) red
38 – 45 (std)
KCCJ3221
(21 lb/in, 3.70 N/mm)
SCMUOH05 (285 lb/in)
yellow
46 to 55 (stiff)
KCCJ3225
(25 lb/in, 4.40 N/mm)
SCMUOH06 (295 lb/in)
white
Specifications - Torque Values
Fastener
Torque Value
Size & Remarks
ft-lb
in-lb
Nm
Cylinder head nuts
10.3
123
14
M7 X 1.0
Crankcase bolts
8.8
105
12
M6 x 1.0
Spark plug
(SP)
(SP)
(SP)
M14 x 1.25
Stator bolts
2.1
25
2.8
M5 X 0.8**
Stator cover bolts
1.7
20
2.3
M4 X 0.75
Clutch cover bolts
5.8
70
7.9
M6 X 1.0
Clutch nut
40
480
54
10 x 1.25*
Clutch bolts
12
144
16
M6 x 1.0*
Engine mount bolts
22
265
30
M8 X 1.25
Swingarm pivot
21
250
28
M14 X 2.0
Shock bolt
35
420
47
M10 x 1.5**
Triple clamp (top)
12
144
16
M8 x 1.25
Triple clamp (bottom)
6
72
8
M6 x 1.0
Water pump impeller
3.6
44
5
M5 x 0.8*
Intake manifold bolts
4.6
55
6.2
M6 X 1.0
Ignition rotor nut
33
400
45
M10 x 1.25**
Rear sprocket bolts
18
216
24
M7 X 1.0**
Axle nuts
25
300
34
M12 X 1.25
* Apply high strength thread locking agent when installing.
**Apply medium strength thread locking agent when installing.
(SP) To apply the proper torque to the spark plug when inserting, first screw the
spark plug in until the metal gasket ring causes resistance and then turn another
¼ turn.
5
Break-In Procedure
Your Cobra CX50 JR is a close-tolerance high performance machine and breakin time is very important for maximum life and performance. The CX50 JR can be
ridden hard after the first ½ hour break-in time.
Cobra recommends Bel-Ray H1-R premix oil with high octane
pump gas mixed at 40:1 (150 ml oil to 2 gallons of gas). Other
brands of oil should be mixed at 32:1 for break-in.
CAUTION:
Failure to use proper fuel, oil, or fuel/oil mixture may result in premature engine
wear or damage to the machine.
Adhering to the following break-in schedule will result in long lasting high
performance machine.
Start bike on stand
First 5 minute period, operate the bike on the stand with a combination of idle
and high RPM operation. (avoid prolonged high RPM but spin the rear
wheel good at least once or twice per minute)
Allow bike to cool
Ride for 15 minutes maximum (avoid prolonged high RPM operation and
avoid abusing the clutch with throttle blipping.
Allow bike to cool and inspect bike for loose fasteners.
Avoid prolonged operation at Wide Open Throttle for the next half hour.
After 1 hour of operation
o Check for loose bolts and nuts.
o Clean the carburetor bowl.
o Change the transmission / clutch lubricant.
Check CFD torque and adjust as necessary
After 8 hours of operation
o Change the fork oil.
o Have a Certified Cobra Mechanic or suspension specialist change the
shock oil.
Your bike is now ready for the highest level of competition!
NOTE: During break-in the bike will likely lose some engine coolant through the
radiator overflow hose. Losing up to 4 oz (120 ml) is normal. Proper coolant level
will cover the top of the radiator cores. Removing the radiator cap and looking
inside is the only way to check the coolant level.
Never remove the radiator cap of a machine that has a warm engine. Burning
and scalding could occur.
6
Starting Procedure
Before starting the machine inspect the following:
Tire pressure
Chain tension
Coolant level
Proper wear on chain rollers and sliders
Handlebar tightness
Throttle assembly movement/cable adjustment
Air Filter
Check for loose nuts and bolts
Turn the fuel on by rotating the fuel petcock knob to the vertically downward
position (reserve position is horizontally forward)
NOTE: For best results from your Cobra Motorcycle use only the recommended
fuel. Testing has shown that most ‘race’ fuels actually degrade performance.
Always wear a helmet and other protective riding gear.
When your pre-ride inspection is complete the bike may be started. For a cold
engine follow this procedure.
1.
2.
3.
4.
5.
6.
Place the motorcycle on a stand of sufficient strength that positions the
motorcycle in a level upright position with the rear wheel off the ground.
Pull up the choke knob and turn it to lock it.
Kick start the engine.
Rev the engine in short spurts, turning the throttle no more than 1/4 open
until the engine will run without the choke.
Verify a functional engine shut-off switch by shutting off the engine.
Restart the engine and proceed with riding when the engine is sufficiently
warm (i.e. the side of the cylinder is warm to touch).
CAUTION:
Never rev an engine full throttle until the engine is at operating temperature.
This is a high performance race motorcycle. Too much application of throttle will
likely land your little racer on his or her arse. Fenders can be replaced but
bruised egos and other body parts take longer.
CAUTION:
Cobra recommends that you tell your child to take it easy the first couple of
minutes in practice until the engine comes up to full operating temperature.
CAUTION:
Make sure your riders’ foot is not resting on the foot brake while they are riding.
7
Maintenance
A properly maintained machine is safer, faster, and more fun to ride. It is
important that you adhere to this maintenance schedule so as to promote the
longevity of your Cobra Motorcycle
Tips
1.
2.
3.
4.
5.
6.
7.
Recommended lubricants:
a. Cobra Clutch Milk is by far the best auto clutch lubricant. It is a
full synthetic lubricant that has been specifically formulated for
Cobra’s auto clutch and has;
Exceptional film strength over petroleum based oils or
synthetic blends.
Extreme temperature tolerance.
NO frictional modifiers.
Dispersant package to keep clutch fibers in suspension so
they can be flushed out when the oil is changed.
Extremely low viscosity for minimal drag and ‘windage’.
b. Bel-Ray H1-R oil is the recommended premix oil because:
Its Ester base leaves a film on all parts at all times. No metal
to metal startups or corrosion potential.
Exception film strength over petroleum based oils or other
synthetic blends.
Easily atomizes and burns completely.
Does not fall out of suspension from premix in cold weather.
Produces virtually no coking deposits, leaving pistons, rings
and heads extremely clean with minimal pipe ‘spooge’.
Filling your transmission with more than 8.0 oz (235 cc) of lubricant will help
to transfer heat from the clutch. Filling with more than 12 oz (295 cc) will
degrade performance.
The cylinder base gasket has been ‘fitted’ for your engine. The code
number stamped into the engine cases will guide you to what thickness
base gasket is required during a common top end service. See the service
section of this manual to correspond a code number with a base gasket part
number.
Evaluate the bikes jetting only after it has been warmed up to race
temperatures.
New chains will stretch on first use. Never install a new chain prior to a
race. Always ‘break’ them in during practice.
Your Cobra motorcycle has a 10 digit VIN (Vehicle Identification Number).
The first two digits indicate the model and the seventh indicates the model
year (MY). Example, CMxxxx7xxx is a 2007 MY CX50 JR.
Because of the amount of heat generated by the clutch and engine during
extended periods of riding, it is advisable to remove the ignition cover
afterward to allow the ignition to cool off. The heat transfers through the
cases and can damage the stator as it cools off because of lack of airflow
around the stator.
8
8.
If you ever need to weld anything on the bike, disconnect the spark plug
cap, unplug the ignition, disconnect the kill switch, scrape the paint bare
near the area to be welded and put the ground clamp as close to the area
to be welded as possible.
Be sure the fuel tank and carburetor have been removed and safely located
away from the welding process.
9.
The frame is 4130 Chrome Moly and it is important to weld it with the proper
rod and heat settings set as light as possible. Cobra recommends replacing
the frame with a new one if the old one becomes damaged. Use ER70S6
filler if welding on the frame.
10. If your kick-starter lever does not return properly, first try loosening the six
kick/clutch cover screws ½ turn. Hold the kick lever ½ way down while
retightening the six screws starting for the center and working out
11. Inspect CFD slip torque after the 2nd ride and then again after the 6th ride.
After this follow the recommended schedule below.
12. Check proper clutch engagement before and after each ride. If the clutch is
engaging properly DO NOT feel the need to take the clutch apart to;
measure the spring stack, clean the stack, replace the springs, etc... Cobra
has worked very hard to make a clutch that is low maintenance and so only
take it apart if it NEEDS to be maintained.
Schedule
Prior to each ride
o Check that the air filter is cleaned and oiled.
o Insure the smooth operation of the throttle cable(throttle soundly ‘clacks’
shut).
o Check for frayed strands of the throttle cable inside the throttle housing.
o Check for adequate tire pressure.
o Check all nuts and bolts for proper torque.
o Spray all moving parts with WD40 or other light oil.
o Check drive chain for

Proper tension.

Adequate lubrication.
o Insure that the ignition stator and rotor are clean and dry.
o Check the frame for cracks in the metal or cracks in the paint that might
Indicate that the metal has been stressed beyond its safe limits.
o Check the rims for signs of stress, like cracks around the rim, spokes
and hub.
o Equalize the pressure in the forks with atmosphere.
Every 2 hours of operation
o Replace the transmission oil.
o Check the CFD torque
Every 10 hours of operation
o Replace the fork oil.
o
Have the shock oil replaced by a Certified Cobra Mechanic.
9
Replacing Transmission / Clutch Lubricant
Tools needed:
5mm allen wrench
Minimum of 235 ml (8 oz) Cobra Venom 3 Shoe Clutch Milk (Part
#MCMUGF32).
Procedure:
1. Begin this procedure with a bike that has been ridden more than 5 minutes
but less than 10 minutes. It is desired to have the engine warm enough so
that the oil is ‘runny’ but not so hot that there is risk of being burned by the
engine or the oil.
Hot oil and hot components on the motorcycle may cause burns.
2. Remove the oil drain plug, on the clutch cover, near the brake lever (figure 1).
Figure 1
3. Allow the oil to drain completely, then reinstall the oil drain plug.
4. Remove the oil fill plug and add 8.0oz of Cobra Venom 3 Shoe Clutch Milk
thru the oil fill plug.
NOTE: Putting additional oil, up to 350 ml (12 oz), can help clutch life. More than
350 ml (12 oz) will degrade engine performance.
NOTE: It can be helpful to lean the bike over on its left side to add oil to the bike.
5. Reinstall the oil fill plug.
NOTE: Cobra has spent considerable time and money developing the proper
lubrication to handle the harsh environment of the automatic clutch and
transmission of this motorcycle. Cobra’s specially developed Cobra Venom 3
Shoe Clutch Milk (Part # MCMUGF32) was formulated to provide superior
lubrication and cooling capability over extended periods of time and is the
recommended lubricant for your Cobra motorcycle.
10
Proper Chain adjustment
Tools required for chain adjustment
19 mm wrench or socket
13 mm wrench or socket
1. Make sure that the rear wheel is aligned
properly.
2. A properly adjusted chain will have
50mm (13/8”) free movement behind
the chain block with no load on the bike.
(figure 2)
Figure 2
3. Sit on the bike and verify that the chain has a
minimum of 12mm (1/2”) free movement when the
chain is at its tightest point.
4. If the chain requires adjusting, loosen the axle
with a 19 mm wrench and tighten the chain by
rotating the adjustor bolts clockwise (CW) or
loosen the chain by rotating the adjustor bolts
(CCW).
5. Retighten the axel bolt to 25 ft-lb (34 Nm).
6. Retighten the adjustor bolt
Rear Brake Maintenance
CAUTION:
Too little brake pedal free-play will allow the brake pads to drag causing the pads
to wear prematurely and possible engine component failures. Too much free-play
will not allow the rider to apply the brakes quickly.
1. Set pedal height/position first, then
2. Set pedal free play.
Brake pedal height can be adjusted with the bolt and nut located under the rear
of the brake pedal. The free-play is adjusted with the adjustable plunger on the
end of the brake pedal.
11
CAUTION:
Use only DOT 4 brake fluid
Setting rear brake pedal position (see figure 2b):
1. Loosen the lock nut (10mm wrench).
2. Adjust the brake lever stop (10mm wrench) so that the lever is comfortably
reachable in both:
a. Standing riding position, and
Figure 2b
b. Sitting riding position.
3. Tighten the lock nut (10 mm
wrench).
CAUTION:
Adequate pedal free play is required
so that the brake pads do not drag on
the rotor. 1” MINIMUM.
Make sure that the free play locking
clip is installed such that one must
push forward, toward the front of the
bike, to remove. Otherwise the clip is
apt to come undone while riding.
To adjust (see figure 2b):
1. Loosen the lock nut (10mm).
2. Undo the free play locking clip from around the brake adjustor (plunger),
with your hand by pushing it forward.
3. Slide the pin of the locking free play locking clip from the brake lever
4. Adjust as needed by rotating the clevis on the end of the adjustor
(plunger).
NOTE: Turning the clevis Clockwise will lengthen the adjustor (plunger),
removing free play from the system, and turning the clevis Counter-Clockwise will
shorten the adjustor (plunger) adding free play to the system.
12
Brake Bleeding Procedure
Tools Required:
Front: T10 Torx bit/driver, Cobra bleed kit (BCKG0031)
Rear: 3mm hex key (Allen wrench, T10 Torx bit/driver, Cobra bleed
kit(BCKG0031)
Procedure:
Remove the brake fluid reservoir cover.
Fill the syringe half full with brake fluid.
Remove the brake caliper bleed screw.
Attach the syringe to the brake caliper bleed access. Keep the syringe
oriented as not to allow air from the syringe into the system.
Using the syringe pull fluid through the system. Use caution not to let the
fluid in the reservoir to become low and introduce air into the system.
Using the syringe push fluid back into the system until the reservoir is full.
Repeat these actions of pulling and pushing fluid through the system a few
times.
With the reservoir full, engage the brake lever/pedal and hold it there as if
engaging the brakes.
While doing this pull on the plunger of the syringe. Doing this will cause a
vacuum in the system. The vacuum will swell the air bubbles which assist
in them moving throughout the system.
Continue pulling a vacuum and release the brake lever/pedal (careful not
to allow the reservoir to become empty).
Once again engage the brakes while continuing to pull a vacuum.
When the reservoir is almost empty stop and push fluid back into the
system.
Repeat these steps with the vacuum until no more air bubbles can be
removed from the system.
Remove the syringe. Be sure to keep the caliper below the level of the
reservoir to allow the fluid to run out of the caliper and not allowing air into
the system.
Reinstall the bleed screw, being sure that the ring is in place.
Fill the reservoir with fluid (the fluid should be full enough that the fluid
spills out when placing the lid on) and replace the cover.
13
Air Filter Cleaning
Tools recommended for air filter maintenance:
#2 Phillips head screwdriver
4 mm Allen wrench
Foam filter oil
Procedure
1. Removed the seat with a 4 mm Allen wrench.
2. Remove the filter/air inlet boot from the back of the carburetor with a Phillips
screwdriver
3. Pull the filter / boot assembly out the top of the air box.
4. Clean the filter in a nonflammable solvent to remove the filter oil.
Do not clean the air filter with gasoline or other highly volatile petroleum product.
Diesel fuel or kerosene would be preferred but caution should still be taken. Hot
soapy water works well.
5. Clean the filter in hot soapy water to remove all dirt particles.
6. Allow it to dry thoroughly.
7. Saturate with filter oil and remove excess.
NOTE: The Cobra is equipped with a special designed Air box. It is very
important to keep the air filter clean and properly oiled with high quality waterresistant foam filter oil. It’s very important to oil your filter consistently each time
because varied amounts of oil will change your carburetor jetting.
8. Reinstall the filter / boot assembly making sure the letters “CM” are visible
between the carburetor and air box (figure 4).
Figure 4
NOTE: Make sure you change or clean your filter after each moto. We
recommend carrying multiple filters in your toolbox, one for each practice session
and moto.
14
Fork Maintenance
Cobra strongly recommends that a professional service technician conduct all
internal maintenance other than changing springs and oil. This will help to ensure
safe and consistent operation.
For routine maintenance, the chart below provides suggested service intervals
for common procedures:
Bleed excess air
Change Oil
Change
Seal/Swiper
Change Bushings
Each Ride
X
10 hours
20 hours
As Needed
X
X
X
Fork Air Bleeding
Tools required
3mm hex key (Allen wrench)
During normal operation, both fork legs will build up air pressure. This pressure
acts as an additional spring so it must be bled on a regular basis to maintain
consistent suspension operation. Before each ride, loosen the socket head cap
screw located at the front of each fork cap far enough so that any excess
pressure in the leg is relieved. After excess air is bled off, retighten the screw to 5
in-lb. Be careful not to lose or damage the sealing ring that is located under the
head of each bleed screw.
Fork Oil Replacement
Tools required
32mm Fork Cap Tool (MCMUTL32)
19mm wrench or socket
4 & 5 mm hex key (Allen wrench)
9/16 wrench
Mallet
2.5 wt. Bel-Ray fork oil
15
Disassembly procedure
1. Remove the front wheel (19 mm wrench).
2. Remove the brake caliper from the fork leg (4 mm hex key).
3. Loosen the fork caps (32mm fork cap tool).
4. Remove the fork legs from the triple clamps (5 mm hex key).
5. One leg at a time
a. Remove the fork cap from the fork tube.
b. Pull the fork spring down to gain access to the fork cap jam nut and
secure it with a 9/16 wrench.
c. Holding in one hand the 9/16 wrench use the fork cap wrench to
unscrew the fork cap from the damper rod.
d. Remove the fork spring pad, and fork spring.
e. Inside the damper rod, the rebound adjustment screw pin is resting
and will fall out of the damper rod when the fork is inverted. Try to
catch it before it falls into your oil bucket.
f. Invert the fork and allow the oil to drain completely. Working the
damper rod up and down will speed up the draining process.
Assembly procedure
1. Fill the fork with 145ml of fork oil.
2. Work the damper rod up and down to allow the fork cartridge to fill with oil.
3. Install the rebound adjustment screw pin into the damper rod.
4. Install the fork spring and spring pad.
5. Extend the damper rod completely and Compress the fork spring enough to
begin threading the fork cap back onto the damper rod.
6. Make sure that the fork cap threads onto the damper rod completely before it
makes contact with the jamnut.
7. Tighten the jamnut.
8. Tighten the fork cap to the fork leg outer
9. Pump the fork leg several times to verify that it operates smoothly.
10. Install each leg back into the triple clamp. Torque each pinch bolt to 8N-m (6
ft-lb) making sure both legs are set to the same height in the clamps.
11. Reinstall the brake caliper.
12. Reinstall the front wheel (25 ft-lb, 34 Nm).
Cobra Frictional Drive (V3 CFD)
The Cobra Frictional Drive (CFD) is essentially an adjustable slip clutch that
dissipates torque spikes transmitted from the rear wheel to the rest of the drive
line and engine. Instead of these torque spikes potentially damaging internal
components, the CFD allows the transmission to slip with respect to the engine.
For this to occur, the CFD must function properly by ‘slipping’ above a minimum
torque value.
The safe minimum slip torque of the CFD should be checked every 2 hours of
operation, after break-in.
16
The slip torque value should be above 60 ft-lb (81 Nm) measured at the sprocket.
To properly measure the minimum torque at which the CFD (Cobra
Frictional Drive) slips
1. Access the slip clutch by draining the oil and removing
the cover exposing the CFD.
2. Brace the CFD gear from turning with a suitable device
(Cobra tool EAMU0004 or similar).
3. Install the Sprocket Socket CFD torque checking tool
(MCMUTL15) on the sprocket and secure with the
supplied screw and ensure that the tool is completely
up against the sprocket
4. Verify with a torque wrench applied to the Sprocket
Socket that the V3 CFD does not slip below 81 Nm (60
ft-lb) in either direction.
5. If there is slippage below 81 Nm (60 ft-lb)
remove the cotter pin and tighten the
nut on the CFD one more position (it is a
hand thread nut so you must turn it
counter clockwise)
castle
left
CAUTION:
Do not check earlier versions of the CFD with this method! The torque valves
required at the sprocket would be much higher
HINT:
This V3 CFD torque checking method is possible do to with the chain on. Just put
the bike on a stand so that the rear wheel can turn freely.
HINT:
The CFD hubs can be removed with the universal puller (MCMUTL70).
17
Parts
Parts – Airbox and Inlet System
Airbox and Inlet System
REF #
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
PART #
ZCCS0001
ECMU0246
RCCS0002
HCWF0601
HCBC0603
MCKGHO04
RCCM0001
RCCM1301
MCKGHO01
RCCJ0004
RCMU0405
TCCJ0004
HCBB0612
RCMU1407
ECCS0030
FCMU0026
MCMUCL04
RCMU0022
DESCRIPTION
GASKET – REED TO CYLINDER
REED CAGE ASSEMBLY WITH REEDS VFORCE
INLET MANIFOLD
6mm FLAT WASHER
M6X30mm SOCKET HEAD CAP SCREW
HOSE CLAMP – CARBURETOR TO MANIFOLD
CARBURETOR 14mm
VELOCITY STACK
HOSE CLAMP – AIR BOOT TO CARBURETOR
AIR FILTER WITH BOOT
AIR BOX - JR
MUD FLAP
M6X12mm BUTTON HEAD BOLT (2 REQ’D)
BRACKET – MUD FLAP
REEDS REPLACEMENT KIT
FUEL LINE 5” (NOT SHOWN)
HOSE CLAMPS – FUEL LINE (NOT SHOWN)
VENT HOSE (NOT SHOWN)
18
Parts – Bars and Controls
Bars and Controls
REF #
1
2
3
4
5
6
7
8
9
10
11
11A
PART #
TCMU0008
FCMU0066
FCPW0004
FCMU0021
FCMU0019
BAKG0003
FCMU0033
HCBC0803
HCBC0825
TKMU0404
TKMU0403
DESCRIPTION
HANDLEBAR - ALUMINUM
GRIPS (SET OF TWO) – SCOTT WAFFLE
THROTTLE ASSEMBLY
CABLE COVER
THROTTLE COVER
THROTTLE CABLE
BRAKE ASSEMBLY FRONT
KILL SWITCH ASSEMBLY
M8X30mm SOCKET HEAD CAP SCREW (4) REQ’D
M8X25mm SOCKET HEAD CAP SCREW (4) REQ’D
BAR MOUNT KIT, SHORT (1 REQ’D) STANDARD
BAR MOUNT KIT, TALL (1 REQ’D)
ACCESSORY
ACCESSORY
ACCESSORY
BCKG0023
BCKG0024
BAKG0004
ALLOY BRAKE LEVER W/BALL
BRAKE PERCH ASSY W/LEVER & BALL
SHIELDED BRAKE HOSE ASSEMBLY
19
Parts - Carburetor
Carburetor
REF. #
1
2
3
4
5
7
8
9
11
12
13
14
15
16
17
NOT SHOWN
20
21
25
26
27
28
29
30
31
NOT SHOWN
NOT SHOWN
NOT SHOWN
NOT SHOWN
NOT SHOWN
NOT SHOWN
NOT SHOWN
NOT SHOWN
NOT SHOWN
NOT SHOWN
NOT SHOWN
NOT SHOWN
48
50
52
55
60
65
PILOT JET
RCMU0048
RCMU0050
RCMU0052
RCMU0055
RCMU0060
RCMU0065
85
86
87
88
89
90
91
RCMU0085
RCMU0086
RCMU0087
RCMU0088
RCMU0089
RCMU0090
RCMU0092
92
93
94
95
96
97
98
20
PART #
RCCM0001
RCMU0305
RCMU0601
RCMU0024
RCMU00xx
RCMU00xx
RCMU0301
RCMU0102
RCMU0003
RCMU0006
RCMU0106
ZCMU0007
RCMU0004
RCMU0028
RCMU0007
RCMU0204
RCMU0209
RCMU0009
RCMU0011
RCMU0103
RCMU0107
RCMU0012
RCMU0016
RCMU0108
HCWF0401
RCMU0201
RCCM1301
RCCM0314
FCMU0026
MCMUCL04
RCMU0020
RCMU0020
RAMU0001
RCMU0031
RCMU0250
ECKG0160
RCMU0026
RCMU0602
MAIN JET
RCMU0092
RCMU0093
RCMU0094
RCMU0095
RCMU0096
RCMU0097
RCMU0098
99
100
101
102
DESCRIPTION
COMPLETE CARBURETOR 14MM
SLIDE - #40
NEEDLE - W7
ATOMIZER AU2.62
MAIN JET, xx denotes size
PILOT JET, xx denotes size
FLOAT
RUBBER CABLE CAP SEAL
CABLE ADJUSTOR
TOP CARB SCREW
CARB TOP
TOP CARB GASKET
SLIDE SPRING
NEEDLE RETAINER PLATE
NEEDLE CLIP
CHOKE ASSEMBLY
O-RING CHOKE ASSEMBLY
FUEL MIXTURE SCREW
IDLE ADJUSTMENT SCREW
FLOAT BOWL GASKET
FLOAT NEEDLE
DIFFUSER
FLOAT RETAINER PIN
FLOAT BOWL
WASHER 4MM FLAT
BOTTOM FLOAT SCREW
VELOCITY STACK – 05 style
14MM CARB RESTRICTOR
FUEL LINE 5”
HOSE CLAMPS – FUEL LINE
ELBOW - CARB VENT
ELBOW - CARB VENT
CANNULUS - Y STYLE CARB VENTS
SLIDE - #30
SLIDE - #50
SLIDE - #60
NEEDLE - W4
NEEDLE - W16
RCMU0099
RCMU1100
RCMU1101
RCMU1102
Parts – Coolant System
Coolant System
REF #
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
PART #
FCCJ0004
MCMUHO02
MCMUCL07
EACJ0001
HCBC0608
HCNL0601
MCKGGR00
MCCMHO01
TCCJ0001
FCMU0049
MCMUCL05
ECHA0109
HCBC0665
FCCJ0002
HCCN0000
HCBC0501
FCMU0022
DESCRIPTION
RADIATOR WITH CAP
RADIATOR HOSE LEFT
HOSE CLAMP
MOUNTING BRACKET – RADIATOR BOTTOM
M6X55mm SOCKET HEAD CAP SCREW
M6 LOCK NUT
GROMMET – RADIATOR MOUNTING
RADIATOR HOSE RIGHT
BUMPER – RAD BRACKET
OVERFLOW HOSE – 20”
HOSE CLAMP, OVERFLOW HOSE
MOUNTING BRACKET – RADIATOR TOP (2 REQ’D)
M6X65mm SOCKET HEAD CAP SCREW
LOUVER SET (LEFT AND RIGHT)
5mm CLIP NUT
M5X12mm SOCKET HEAD CAP SCREW
CAP, 1.2 BAR
21
Parts – Electrical System
Electrical System
REF #
1
2
2A
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
ACCESSORY
PART #
ICCJ0001
ECMU0010C
ECMU0010I
FCMU0033
HCBH0502
HCWF0501
HCWP0002
HCNL0501
ICMU0018
HCBC0535
HCBC0525
HCWF0504
ICMU0036
ECKG0042
HCNS1001
ECCS0001
ZCCS0002
HCBC0402
ICMU0012
ICMU0017
DESCRIPTION
COIL W/SPARK PLUG CAP
SPARK PLUG, AUTOLITE COPPERLITE
SPARK PLUG, AUTOLITE IRIDIUM
KILL SWITCH ASSEMBLY
M5X16mm HEX HEAD SCREW (2 REQ’D)
5mm WASHER (2 REQ’D)
5mm WASHER SPECIAL (2 REQ’D)
M5 LOCKNUT (2 REQ’D)
STATOR WITH GROMMET
M5X35mm SOCKET HEAD CAP SCREW (2 REQ’D)
M5X25mm SOCKET HEAD CAP SCREW
WASHER FOR STATOR (3 REQ’D)
ROTOR – LOW INERTIA
PULLEY, WATERPUMP CRANK
M10 NUT
IGNITION COVER
GASKET – IGNITION COVER
M4X35mm SHCS (4 REQ’D)
WOODRUFF KEY (NOT SHOWN)
SPARK PLUG CAP – 0
22
Parts – Engine – Bottom End and
Transmission
Engine Bottom End and Transmission
REF #
1&2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
23
23
23
24
25
26
27
PART #
EKCS0003
ZCCS0005
HCBC0605
HCBC0608
HCBC0606
ECMU0057
ECMU0016
ECMU0118
HCDP1401
DECMU0999
ECMU0100
ECMU0001
ECKG0031
HCBH0612
HCWF0316
ECMU0020L
ECKGBR01
ZCDCOR01
ECMU0072
ECMU0073
ECKGSR03
PCKG0013
PCKG0012
PCKG0014
PCKG0015
HCBH0805
HCWC0000
ECMU0233
ECMU0577
DESCRIPTION
ENGINE CASE SET W/B&S 50 2012
GASKET, CRANKCASE CENTER
M6X40mm SOCKET HEAD CAP SCREW (6 REQ’D)
M6X55mm SOCKET HEAD CAP SCREW (1 REQ’D)
M6X45mm SOCKET HEAD CAP SCREW (2 REQ’D)
CRANKSHAFT - 3 SIDE SPLINE
BEARING, CRANKSHAFT
SEAL, CRANKSHAFT
DOWEL, ENGINE CASE ALIGNEMENT (2 REQ’D)
OUTPUT SHAFT, TRANSMISSION WITH GEAR
SECONDARY SHAFT, TRANSMISSION WITH GEAR
BEARING, TRANMISSION SECONDARY SHAFT
BEARING OUTPUT SHAFT, RIGHT SIDE
M6X12mm HEX HEAD SCREW - BEARING RETAINER (2 REQ’D)
WASHER - FLAT
BEARING, TRANSMISSION PRECISION
BEARING, TRANSMISSION OUTPUT SHAFT
O-RING, SPROCKET SPACER
SEAL, OUTPUT SHAFT
SPACER, SPROCKET
SNAP RING, SPROCKET
SPROCKET, 13 T (STANDARD)
SPROCKET, 12T
SPROCKET, 14 T
SPROCKET, 15 T
M8X12mm SCREW – COOLANT DRAIN
COPPER GASKET
FITTING, CRANKCASE VENT - LARGE
VENT HOSE, CRANKCASE
23
Parts – Engine Clutch and Kicker
Engine – Clutch and Kick Starter
REF #
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
PART #
CAMU0006
CAMU0013
CCMU0005
CAMU0010
HCBS0004
ECMU0018
CCMU0007
ECMU0120
ECMU0119
ECMU0040
ECMU0132
ECMU0306
ECMU0249
ECMU0305
ECMU0301
ECMU0308
ECMU0307
HCCP0002
EAMU0001
ECMU0116
ZCMUB014
HCWS1622
ECDC0036
EAMU0011
ECMU0250
HCFH0625
ECMU0115
ZCMU0030
ECMU0168
ZCMUB014
HCBC0608
ECMU0207
ECMUSP01
DESCRIPTION
CLUTCH COMPLETE
CLUTCH SHOES (SET OF 3) WITH BOLT & WASHERS
CLUTCH ARBOR
SPRINGS, WASHERS & BOLTS (SET OF 3)
CLUTCH BOLT (3 REQ’D)
CLUTCH NUT, SPECIAL
CLUTCH BACKING SPACER
CLUTCH BASKET WITH NEEDLE BEARING
CLUTCH BEARING
CLUTCH TO HUB SPACER (0.030”, 0.76mm)
COOLANT FITTING
SLIP HUB V3 CFD (2) REQ’D
FRICTION MATERIAL V3 CFDTHICK (2 REQ’D)
BUSHING V3 CFD 7mm
GEAR V3 CFD
BELLEVILLE SPRING V3 CFD
NUT V3 CFD
COTTER PIN 3/32 X 1 ½”
KICKSTART GEAR & SHAFT
SPRING, KICKSTART
O-RING KICK SHAFT (2 REQ’D)
SHIM, KICK SHAFT
SNAP RING, KICK SHAFT
KICK LEVER
WASHER – KICK LEVER MOUNTING
M6X25mm FLANGE HEAD BOLT
CLUTCH COVER
CLUTCH COVER GASKET
OIL FILL PLUG, ALUMINUM
O’RING, OIL FILL PLUG
M6X55mm SOCKET HEAD CAP SCREW (6 REQ’D)
KICKSTART GEAR SMALL
KICK START DOG SPRING (PAPER CLIP / ‘J’ SPRING)
ACCESSORY
ACCESSORY
KIT
KIT
HKCP0001
EKMU0002
EKMU0013
EKMU0033
10 PACK OF COTTER PINS (HCCP0002)
KICKSTART PIVOT KIT SPRING-BALL-SCREW
COMLETE GEAR CFD UPGRADE KIT
CFD RFRESH KITW/NUT, SPRING, AND FRICTIONS
24
Parts – Engine – Water Pump
Engine – Water Pump
REF #
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
PART #
EKMU0011
ECKG0142
ECKG0072
ECKG0074
ECKG0073
HCBC1512
ECMU0167
ECKG0175
ECMU0180
HCBS0003
ECKG0170
ECKG0042
HCNS1001
HCBC0408
HCWF0401
DESCRIPTION
WATER PUMP KIT WITH IMPELLER
SHAFT, WATER PUMP
BEARING, WATER PUMP
SEAL, WATER PUMP SHAFT
IMPELLER, WATER PUMP (ALUMINUM)
M5X12mm SOCKET HEAD CAP SCREW (STAINLESS)
BEARING –WATER PUMP BIG
WATER PUMP PULLEY, FAN TYPE – DRIVEN
BELT RETAINER
SHOULDER BOLT 6mm
WATER PUMP BELT
WATER PUMP PULLEY, CRANK
M10 NUT
M4X8mm SOCKET HEAD CAP SCREW (BLACK OXIDE)
4mm WASHER
25
Parts – Engine – Top End
Engine – Top End
REF #
1
2
2
2
2
2
2
3
3
3
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
ACCESSORY
ACCESSORY
PART #
ECCJ0001
ZCMU0011
ZCMU0703
ZCKG0501
ZCMU0705
ZCMU0706
ZCMU0708
ECMU0060A
ECMU0060B
ECMU0060C
ECMU0060D
ZCMOTE11
ECMU0155
ECMUSR00
ECKG0012
ECMU0077
ZCMUOR07
ECMU0086
HCBC0612
HCNS0703
HCWS1401
ECMU0530
ZCMUOR02
ZCMUV024
ZCMUOR10
ECCS0017
ZCMUOR05
ECMU0147
ZKMUOR11
ZKCSTE11
DESCRIPTION
CYLINDER (INCLUDES PISTON, RINGS, PIN & CLIPS)
BASE GASKET (0.25mm) THICK
BASE GASKET (0.30mm) THICK
BASE GASKET (0.40mm) THICK (STANDARD)
BASE GASKET (0.50mm) THICK
BASE GASKET (0.60mm) THICK
BASE GASKET (0.80mm) THICK
PISTON KIT – ‘A’ SIZE
PISTON KIT – ‘B’ SIZE
PISTON KIT – ‘C’ SIZE
PISTON KIT – ‘D’ SIZE
O-RINGS – PIPE TO FLANGE (2 REQ’D)
PISTON RINGS (2 PER SET)
SNAP RING FOR PISTON (2 PER SET)
WRIST PIN
BEARING, WRIST PIN
O-RING, EXHAUST FLANGE
EXHAUST FLANGE
M6X12, EXHAUST FLANGE SCREW (2 REQ'D)
7mm NUT - TALL (4 REQ'D)
HARDENED WASHER (4REQ’D)
CYLINDER HEAD OUTER
O-RING, CYLINDER HEAD LARGE
O-RING CYLINDER HEAD SMALL
O-RING CYLINDER STUD (4 REQ'D)
CYLINDER HEAD, INSERT
O-RING CYLINDER HEAD MEDIUM – YELLOW
STUD, CYLINDER 7mm (4 REQ’D)
TOP END/O-RING KIT
TOP END/GASKET KIT
26
Parts – Exhaust System
Exhaust System
REF #
1
2
3
4
5
6
7
8
9
10
ACCESSORY
PART #
XCCJ2009
ZCMOTE11
XCMU0005
MCMUGR02
XCMU0028
XCMU0032
MCMUGR03
TCKG0001
HCWF1478
HCBF0625
XCMU0026
DESCRIPTION
CX50JR EXHAUST PIPE
HEADER PIPE O-RINGS (2 REQ’D)
EXHAUST SPRING - SHORT
GROMMET KIT
PIPE / SILENCER SEAL
SILENCER
MOUNTING GROMMET (2 REQ’D)
SPACER (2 REQ’D)
SILENCER GROMMET WASHER (2 REQ’D)
M6X25mm FLANGE HEAD BOLT (2 REQ’D)
SILENCER PACKING KIT
27
Parts – Forks & Triple Clamps
Front Forks and Triple Clamps
REF #
1
2
3
4
5
6
7
8
9
10
11
12
13
13A
14
15
16
17
18
19
20
21
22
PART #
KACJ0001
KCMU0011
TCC60019
HCBC0601
BCC60015
HCBC0612
HCNL0601
FACJ0004
FCCJ2005
HCNJ0102
HCBC0806
HCBC0820
TKMU0404
TKMU0403
FCMU1103
SCMU0036
FCMU0023
FCMU0024
FCMU0004
HCBC0625
HCBF0616
HCBC0825
FCMU0011
DESCRIPTION
FORK ASSEMBLY FORK LEGS ONLY
FORK GUARD SET
WASHER FORK GUARD (4 REQ’D)
M6X16mm, SOCKET HEAD CAP SCREW (4 REQ’D)
BRAKELINE CLAMP
M6X12mm, SOCKET HEAD CAP SCREW (2 REQ’D)
M6 LOCKNUT (2 REQ’D)
TRIPLE CLAMP BOTTOM ASSY JR (CLAMP & STEERING STEM)
TRIPLE CLAMP TOP JR
JAM NUT STEERING STEM (2 REQ’D)
M8X30mm SOCKET HEAD CAP SCREW (4 REQ’D)
M8X20mm SOCKET HEAD CAP SCREW (4 REQ’D)
HANDLE BAR CLAMP KIT SHORT (STANDARD)
HANDLE BAR CLAMP KIT TALL
DUST COVER (2 REQ’D)
O-RING (2 REQ’D)
SPACER (2 REQ’D)
SEAL (2 REQ’D)
STEERING HEAD BEARING (2 REQ’D)
M6X25mm SOCKET HEAD CAP SCREW (4 REQ’D)
M6X16mm FLANGED HEAD W/8mm HEX
M8X25mm SHCS (4 REQ’D)
STEERING HEAD RACE (2REQ’D)
ACCESSORY
FKMU0003
KIT – STEERING STEM BEARINGS, RACES AND SEALS
28
Parts – Forks –
Leg Assembly
– Brake Side
REF #
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
15
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
333
33
34
35
36
37
38
PART #
DESCRIPTION
HCBC0408
ZCKG0001
KCCS0004C
ZCMUOR18
KCCS0036
KCCS0005
KCCS0035
KCCS0006
KCCS0032
KCMZ0015
KCCS0002
KCMZ0013
KCC60067
KCCS0013
KCCS3225
KCCS3223
KCCS3227
HCNJ3824
KCC60068
KAC60003
KCC60058
KCC60050
KCC60051
KCCS0018
HCNJ0601
BCKG0033
KCCS0033
KCC60049
KCCS0001
KCKG0050
KCCJ0002
KCKG0019
KCMU0021
ZCKGB017
KCC60069
KCC60048
ZCMUOR03
KCCS0031
4 X 8 SHCS CLEAR ZINC
GASKET, BLEED SCREW FORK
FORK CAP - CONVENTIONAL 32MM USD
O-RING PV SOLENOID - CX65
FORK - SPRING WEAR PLATE 32MM
FORK - OUTER TUBE 32MM
RING CLIP FORK OUTER WEAR RING 32MM
FORK GLIDE RING BOTTOM 32MM
FORK SEAL SPACER 32MM
FORK SEAL - MARZ32
RING CLIP - FORK SEAL RETAINER - 32MM
FORK SWIPER - MARZ32
FORK JOUNCE BUMPER
FORK SPRING GUIDE 32MM
STANDARD SPRING - FORK 0.25 KG/MM 32mm
LIGHT SPRING - FORK 0.23 KG/MM 32mm
HEAVY SPRING - FORK 0.257KG/MM 32mm
NUT JAM 3/8-24 CLASS 8
RING CLIP - FORK SPRING GUIDE RETAINER
DAMPER ROD ASSEMBLY
O-RING MID-VALVE ADJ NEEDLE
FORK MID-VALVE ADJUSTER NEEDLE
SPRING - FORK ADJUSTER NEEDLE
SEAL - FORK PISTON - MID VALVE
6MM JAM NUT
O-RING – 2MMID
FORK - ADJUSTER SCREW TOP 32MM
FORK - ADJUSTER PIN
FORK - CARTRIDGE CAP
FORK - TOP OUT SPRING
FORK - TRAVEL LIMITER SPACER
FORK - CARTRIDGE TUBE
O-RING - FORK - BASE VALVE
O-RING - FORK BOTTOM PLUG
FORK BOTTOM PLUG – ADJUSTABLE
ADJUSTMET SCREW – FORK BOTTOM PLUG
O-RING – ADJUSTMENT SCREW
RING CLIP – FORK ADJUSTMENT SCREW
KCCS0007
KAMU0001
FORK GLIDE RING
FORK LOWER – COMPLETE – BRAKE SIDE
29
Parts – Forks – Leg Assembly – Non-Brake Side
REF #
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
15
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
PART #
HCBC0408
ZCKG0001
KCCS0004S
ZCMUOR18
KCCS0036
KCCS0005
KCCS0035
KCCS0006
KCCS0032
KCMZ0015
KCCS0002
KCMZ0013
KCC60067
KCCS0013
KCCS3225
KCCS3223
KCCS3227
HCNJ3824
KCC60068
KAC60003
KCC60058
KCC60050
KCC60051
KCCS0018
HCNJ0601
BCKG0033
KCCS0033
KCC60049
KCCS0001
KCKG0050
KCCJ0002
KCKG0019
KCMU0021
KCC60057
KCCS0007
KAMU0002
DESCRIPTION
4 X 8 SHCS CLEAR ZINC
GASKET, BLEED SCREW FORK
FORK CAP - CONVENTIONAL 32MM USD
O-RING PV SOLENOID - CX65
FORK - SPRING WEAR PLATE 32MM
FORK - OUTER TUBE 32MM
RING CLIP FORK OUTER WEAR RING 32MM
FORK GLIDE RING BOTTOM 32MM
FORK SEAL SPACER 32MM
FORK SEAL - MARZ32
RING CLIP - FORK SEAL RETAINER - 32MM
FORK SWIPER - MARZ32
FORK JOUNCE BUMPER
FORK SPRING GUIDE 32MM
STANDARD SPRING - FORK 0.25 KG/MM 32mm
LIGHT SPRING - FORK 0.23 KG/MM 32mm
HEAVY SPRING - FORK 0.257KG/MM 32mm
NUT JAM 3/8-24 CLASS 8
RING CLIP - FORK SPRING GUIDE RETAINER
DAMPER ROD ASSEMBLY
O-RING MID-VALVE ADJ NEEDLE
FORK MID-VALVE ADJUSTER NEEDLE
SPRING - FORK ADJUSTER NEEDLE
SEAL - FORK PISTON - MID VALVE
6MM JAM NUT
O-RING – 2MMID
FORK - ADJUSTER SCREW TOP 32MM
FORK - ADJUSTER PIN
FORK - CARTRIDGE CAP
FORK - TOP OUT SPRING
FORK - TRAVEL LIMITER SPACER
FORK - CARTRIDGE TUBE
O-RING - FORK - BASE VALVE
PLUG – FORK BOTTOM – SMART LEG
FORK GLIDE RING
FORK LOWER – COMPLETE – NON BRAKE SIDE
30
Parts – Frame – Mounting Hardware I
Frame – Engine, Swingarm, Tank, and Pipe Mounts
REF #
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
PART #
WCMU0016
HCNL1201
HCBH0880
HCNL0801
MCMUGR02
HCBF0635
HCHA0003
TCHA0004
HCNL0601
TCHA0006
HCBF0685
HCBB0635
HCBF0620
HCNF0602
HCBF0625
MCMUGR03
TCKG0001
HCWF1478
HCBF0616
FCC60020
TAMU0005
FCMU0031
HCWF0803
HCCP0008
TCMU0107
BCMU0027
HCBC0601
FCEX0018
DESCRIPTION
SWINGARM BOLT
M12 SWINGARM LOCK NUT
M8X80mm SOCKET HEAD CAP SCREW
M8 LOCKNUT
GROMMET KIT PIPE & SPACER
M6X35mm FLANGE HEAD BOLT
6mm CLIPNUT
BUSHING – REAR TANK MOUNTING
M6 LOCKNUT
BUSHING – FRONT TANK MOUNT (2 REQ’D)
M6X85mm SOCKET HEAD CAP SCREW
M6X35mm BUTTON HEAD CAP SCREW
M6X20mm FLANGE HEAD BOLT
M6 NYLOC FLANGE NUT
M6X25mm FLANGE HEAD BOLT
GROMMET – SILENCER (2 REQ’D)
SPACER FOR EXHAUST GROMMETS
WASHER – EXHAUST GROMMET
M6X16mm FLANGE HEAD BOLT
CHAIN ROLLER
FOOTPEGS (PAIR) (STANDARD)
CLEVIS PIN - FOOTPEG
8mm FLAT WASHER
COTTER PIN 1/8 X 3/4
FOOTPEG SPRINGS (SINGLE PIECE) (2 REQ’D)
BRAKE PIVOT BOLT
M6X16mm SOCKET HEAD CAP SCREW
BRAKE ADJUST ECCENTRIC
31
Parts – Frame – Mounting Hardware II
Frame – Seat, Fender, Right Side Panel, Radiator & Shock Mounts
REF #
1
2
3
4
5
6
7
8
9
10
11
12
13
14
PART #
FACJ2012
HCBF1040
ECCJ0001
HCBC0608
HCNL0601
MCKGGR00
ECHA0109
HCBC0665
HCBF0616
HCHA0003
HCBH0502
HCWP0002
HCNL0501
HCWF0501
DESCRIPTION
FRAME CX50 JR
M10X40mm FLANGE HEAD BOLT
MOUNTING BRACKET – RADIATOR BOTTOM
M6X55mm SOCKET HEAD CAP SCREW
M6 LOCK NUT
GROMMET – RADIATOR MOUNT (2 REQ’D ON BOTTOM, 2 ON TOP BRACKET)
MOUNTING BRACKET – RADIATOR TOP (2 REQ’D)
M6X65mm SOCKET HEAD CAP SCREW
M6X16mm FLANGE HEAD BOLT
6mm CLIPNUT
M5X16mm HEX HEAD (2 REQ’D)
WASHER POP RIVET (2 REQ’D)
M5 LOCKNUT (2 REQ’D)
5mm FLAT WASHER (2REQ’D)
32
Parts – Front Brakes
Front Brakes
REF #
1
2
3
4
5
6
7
8
9
10
PART #
BAKG0003
BCKG0030
BCKG0023
BCKG0024
BCKG0029
BKKG0001
BCMU0503
HCBC0501
HCBF0640
HCBF0620
DESCRIPTION
FRONT BRAKE ASSEMBLY
HOSE – BRAKE FRONT
ALLOY BRAKE LEVER
BRAKE PERCH & MASTER CYLINDER ASSY W/ LEVER
CALIPER – FRONT
KIT BRAKE PADS, WITH “E” CLIP
BRAKE ROTOR
M5X12mm SOCKET HEAD CAP SCREW (6 REQ’D)
M6X40mm FLANGE HEAD CAP SCREW
M6X20mm FLANGE HEAD CAP SCREW
ACCESSORY
MCMUBF01
BCKG0031
BCKG0028
BCKG0027
BCKG0025
BCKG0026
BCKG0017
BCKG0018
BCKG0019
ZCMUOR09
BCMU0014
BCKG0033
BRAKE FLUID **DOT 5.1 OR HIGHER**
BLEED KIT (MULTIPLE SYRINGES, FITTINGS & HOSE)
LEVER ADJUSTMENT KIT
RESERVOIR SEAL KIT
REPLACEMENT BAR CLAMP AND SCREWS (FOR MASTER CYLINDER)
PISTON & REBUILD KIT FOR MASTER CYLINDER
CALIPER ORING & BOLTS (F&R)
CALIPER PISTON KIT (F&R)
RETURN SPRING (4 FINGER SPRING)
O’RING - BANJO FITTING
CALIPER ADJUSTMENT SHIMS 6mm ID
O-RING - BLEEDER - 2mm SPECIAL
ACCESSORY
ACCESSORY
ACCESSORY
ACCESSORY
ACCESSORY
ACCESSORY
ACCESSORY
ACCESSORY
ACCESSORY
ACCESSORY
ACCESSORY
33
Parts – Front Wheel
Front Wheel
REF #
1
2
3
4
5
6
7
8
9
10
11
12
PART #
WACJ0001
WCMU0016
HCBC0501
BCMU0503
WCMU0101
WCMU0120
WCCJ0004
WCCJ0003
HCWF1202
HCNL1201
WCMUTU10
WCMU1050D
DESCRIPTION
WHEEL WITH BEARINGS SPOKE STYLE
FRONT AXLE
M5X12mm SOCKET HEAD CAP SCREW (6 REQ’D)
BRAKE ROTOR – FRONT
WHEEL SPACER LEFT (SHORT)
BEARING – WHEEL (2 REQ’D)
SPACER – WHEEL FRONT
WHEEL SPACER RIGHT (LONG)
WASHER – AXLE
LOCK NUT – AXLE
TUBE 10”
FRONT TIRE 10” X 2.50” DUNLOP MX51
34
Parts – Plastic & Seat
Plastic and Seat
REF #
1
1
1A
2
2
2A
3&4
3&4
3A
5
5A
5B
5C
5D
5E
5F
5G
6
7
8
9
9A
9B
9C
10 & 11
10 & 11
10A
10B
10C
10D
10E
10F
12
12
12A
PART #
TCHA0107Y
TCHA0107x
HCBF0616
TCC60002W
TCC60002x
HCBF0616
TCCJ0005Y
TCCJ0005x
TCMU0032
TCHA0001
HCFH0620
TCHA0005
TCHA0006
HCBC0685
HCNL0601
HCBC0645
TCHA0004
TCHA0002
TCHA0003
TCMU0151
TCCM0007
TCCM0007C
HCBB0640
MCMU0013
TCCJ0003W
TCCJ0003x
HCBF0616
HCBF0620
HCNF0602
HCBF0616
HCBF0620
HCNF0602
TCHA0112Y
TCHA0112x
HCBF0616
DESCRIPTION
FRONT FENDER
FRONT FENDER x – DENOTES COLOR BLK, WHT, YEL, FLO
FENDER BOLT, M6X16mm FLANGE HEAD (4 REQ’D)
NUMBER PLATE – FRONT
FRONT PLATE x – DENOTES COLOR BLK, WHT, YEL
M6X16mm FLANGE HEAD BOLT – FRONT NUMBER PLATE MOUNT
RADIATOR SHROUD SET (LEFT & RIGHT) – YELLOW
RADIATOR SHROUD SET x - COLOR BLK, WHT, YEL, FLO
RADIATOR PAD
FUEL TANK – NO CAP OR PETCOCK
M6X20mm PHILIPS HEAD SCREW – SEAT & SHROUD HOLD
SPACER – SEAT & SHROUD HOLD
SPACER – FRONT TANK MOUNT (2 REQ’D)
M6X85mm SHCS – FRONT TANK MOUNT
M6 LOCK NUT – FRONT TANK MOUNT BOLT
M6X45mm SOCKET HEAD CAP SCREW
BUSHING – REAR TANK MOUNTING
CAP – FUEL TANK
HOSE – FUEL CAP
FUEL PETCOCK
SEAT
SEAT COVER REPLACEMENT
M6X40mm SHCS – SEAT HOLDING
STRAP HANDLE
NUMBER PLATE SET (LEFT AND RIGHT) - WHITE
NUMBER PLATE SET x – DENOTES COLOR BLK, WHT, YEL
M6X16mm FLANGE HEAD BOLT – FRONT SECURE
M6X20mm FLANGE HEAD BOLT – FENDER & REAR SECURE
M6 NYLOC FLANGE NUT
M6X16mm FLANGE HEAD BOLT – FRONT SECURE
M6X20mm FLANGE HEAD BOLT – FENDER & REAR SECURE
M6 NYLOC FLANGE NUT
FENDER – REAR
FENDER – REAR x – DENOTES COLOR BLK, WHT, YEL, FLO
M6X16mm FLANGE HEAD BOLT – FENDER & AIRBOX
ACCESSORY
ACCESSORY
ACCESSORY
ACCESSORY
TCMU2012
TCKJ0002B
TCKJ0002W
TCKJ0002Y
GRAPHIC KIT
BODYWORK KIT - JR - BLACK
BODYWORK KIT - JR - WHITE
BODYWORK KIT - JR - YELLOW
35
Parts – Rear Brake
Rear Brake System
REF #
1
2
3
4A
4B
4C
5
6
7
8
9
10
11
12
13A
13B
14
15
16
17
18
19
20
21
PART #
BAKG0002
BCMU0027
BCMU0501
BCMU0023
BCMU0023T
HCBC0501
BCMUSP02
HCBC0601
FCEX0018
BACJ0003
BCKG0006
BCKG0103
HCBF0635
HCBF0620
HCCC0000
HCCC0006
HCPP0832
BCMU0502
HCBC0601
HCBF0620
BCKG0012
BCKG0010
BCKG0013
BCMU0022
DESCRIPTION
BRAKE SYSTEM – REAR (M/C-LINE-CALIPER)
BRAKE PIVOT BOLT
SEAL – BRAKE PEDAL (2 REQ’D)
BRAKE PEDAL
TOE PIECE
M5X 12mm SOCKET HEAD CAP SCREW
BRAKE RETURN SPRING
M6X16mm SOCKET HEAD CAP SCREWS
BRAKE ADJUST ECCENTRIC
PUSH ROD, REAR BRAKE
WHEEL SPACER - FLOATING CARRIER
BRAKE CARRIER WITH PAD
M6X35mm FLANGE HEAD BOLT
M6X20mm FLANGE HEAD BOLT
BRAKE HOSE CLAMP (2 REQ’D) for hose with clear cover
BRAKE HOSE CLAMP (2 REQ’D) for hose with black cover
BRAKE HOSE CLAMP FASTENER (2 REQ’D)
BRAKE ROTOR
M6X16mm SOCKET HEAD CAP SCREWS (5 REQ’D)
M6X20mm FLANGE HEAD BOLT (2 REQ’D)
BRAKE – MASTER CYLINDER - REAR
REPLACEMENT BRAKE HOSE
CALIPER – REAR BRAKE
BRAKE – RUBBER CAP
ACCESSORY
ACCESSORY
ACCESSORY
ACCESSORY
ACCESSORY
ACCESSORY
ACCESSORY
ACCESSORY
ACCESSORY
BKKG0001
BCKG0031
BCKG0014
BCKG0015
BCKG0016
BCKG0017
BCKG0018
BCKG0019
ZCMUOR09
BRAKE PADS WITH “E” CLIP
BLEED KIT (MULTIPLE SYRINGES, FITTINGS & HOSE)
FITTING KIT
MASTER CYLINDER PISTON / SEAL KIT
RESERVOIR SEAL KIT
CALIPER BOLT / O-RING KIT
CALIPER PISTON / SEAL KIT
PAD RETURN SPRING (4 LEG SPRING)
O-RING - BANJO FITTING
36
Parts – Rear Wheel
Rear Wheel
REF #
1
2
3
4
5
6
6A
7
7A
7B
8
10
11
12
13
14
15
16
17
18
19
ACCESSORY
PART #
WAKG2007R
WCMU1075D
WCMUTU10
PCMU0001
PCMU0100
PCMU0138
PCMU01xx
HCBH0702
HCWF0701
HCNL0701
WCMU0016
WCMU0101
WCMU0120
WCMU0034
WCMU0020
BCMU0502
HCBC1616
BCKG0103
BCKG0006
HCWF1202
HCNL1201
DESCRIPTION
REAR WHEEL W/BEARINGS
TIRE – REAR 10X2.75” DUNLOP MX51
TUBE, 10"
MASTER LINK 420
CHAIN 420 X 100
38T SPROCKET (STANDARD)
SPROCKET xx DENOTES TEETH – RANGE OF TEETH (34-45)
M7X30mm HEX HEAD BOLT (4 REQ’D)
7mm FLAT WASHER (4 REQ’D)
M7 LOCKNUT (4 REQ’D)
REAR AXLE
WHEEL SPACER
WHEEL BEARING SPROCKET SIDE
WHEEL BEARING SPACER
WHEEL BEARING BRAKE SIDE
BRAKE ROTOR
M6X16mm SOCKET HEAD CAP SCREWS (5 REQ’D)
BRAKE CARRIER
WHEEL SPACER - FLOATING CARRIER
AXLE WASHER
AXLE NUT 12MM
BCKG0104
BRAKE CARRIER PAD
37
Parts – Shock
Rear Shock
REF#
1
2
3
4
5
6
7
8
9
10
10
10
11
PART #
SACJ2012
SCMU0043
SCMU0039
SCMU0042
SCMU0058
SCMU0056
SCMU0100
SCMU0040
SCMU0054
SCMUOH05
SCMUOH04
SCMUOH06
HCBF1040
DESCRIPTION
SHOCK ABSORBER
SHOCK – BEARING SPERICAL SHOCK MOUNT – (2REQ’D)
O-RING – SHOCK – BUSHING (4 REQ’D)
SHOCK – MOUNT BUSHING (4 REQ’D)
SHOCK – WHITE NYLON TIP SET SCREW M6-1.0
SHOCK – SLEEVE BLACK
BUMPER – TAPPERED - SHOCK
SHOCK – SPRING PAD
SHOCK SPRING PERCH
SPRING – STANDARD (285 lb/in)
SPRING – LIGHT (275 lb/in)
SPRING – HEAVY (295 lb/in)
M10X40 FLANGE HEAD BOLT
38
Parts – Shock - Inside
Rear Shock
REF#
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
PART #
SCMU0037
SCMU0038
SCMU0036
SCC60007
SCMU0051
SCMU0052
SCMU0033
SCMU0050
SCMU0035
HCBB0506
SCMU0044
SCMU0048
SCMU0046
SCMU0034
SCMU0047
SCMU0045
SCC60014
DESCRIPTION
O-RING LOW SPEED COMP ADJUSTER
O-RING HIGH SPEED COMP ADJUSTER
O-RING COMP ADJUSTER CAP
O-RING COMPRESSION ADJUSTER
O-RING - IFP
IFP SEAL BAND
O-RING SHOCK BASE
RESERVOIR CAP RETAINER RING
O-RING CHARGE CAP
M5 X 6mm LONG BUTTON HEAD STAINLESS STEEL
SEAL HEAD BUMPER
SHAFT BUSHING
X-RING SEAL
O-RING SEAL HEAD
SPACER - X-RING
DUST SEAL
PISTON BAND
39
Parts – Swingarm Assembly
Swingarm
REF #
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
22
23
24
25A
25B
26
PART #
GACJ2011
GCMU0001
GCCJ0001
GCMU0017
HCFH0512
HCWF0501
HCNL0501
HCBF0620
PAKG0001
PCKG0004
HCBFT640
HCNL0601
FAMU0005
FCMU0203
FCMU0202
HCWF0801
HCBH0810
WCMU0016
HCNL1201
WCMU0016
HCWF1202
HCNS1201
HCBF1040
HCCC0000
HCCC0006
HCPP0832
DESCRIPTION
SWINGARM
SWINGARM BUSHING (SINGLE PIECE) (4 REQ’D)
SPACER - PIVOT TUBE (2REQ’D)
CHAIN GUARD
M5X12mm FLAT HEAD SCREW
5mm FLAT WASHER
M5 LOCK NUT
M6X20mm FLANGE HEAD BOLT (2 REQ’D)
CHAIN GUIDE – ASSEMBLY COMPLETE
CHAIN GUIDE - BOTTOM SLIDER
M6X40mm FLAT HEAD BOLT (2 REQ’D)
M6 LOCKNUT (2 REQ’D)
WHEEL PULL ASSEMBLY ((BLOCK, CAP, BOLT, AND WASHER)
WHEEL PULL
WHEEL PULL ENDCAP
8mm FLAT WASHER
M8X65mm HEX HEAD BOLT (FULL THREAD)
SWINGARM PIVOT BOLT 195mm
M12 LOCK NUT
AXLE BOLT 195mm
AXLE WASHER
M12 LOCK NUT
M10X40mm FLANGE HEAD BOLT
BRAKE HOSE CLAMP (2 REQ’D) for hose with clear cover
BRAKE HOSE CLAMP (2 REQ’D) for hose with black cover
BRAKE HOSE CLAMP FASTENER (2 REQ’D)
40
Service
Trained technicians with precision gauging and proper assembly fixtures carefully
assemble all Cobra engines to specific tolerances. If you feel you have the skills,
and the appropriate tools, to perform the following service tasks please follow the
instructions closely. The part numbers are listed throughout to help you when
ordering parts from your local Cobra dealer.
If you do not feel comfortable with the service work log on to:
www.cobramotorcycle.com to find a cobra dealer or call 517-437-9100.
Engine Service
One method for determining whether the top end of your engine needs rebuilt is
to perform a wide open throttle kicking compression test. Before performing the
procedure please read the caution notes below.
CAUTION:
There is a large wide range of variability in reading compression gauges.
The head volume of this Cobra Motorcycle is very small and requires 20 kicks
before you establish the most accurate reading possible.
Because of the geometry of the spark plug used in this Cobra Motorcycle, the
adapter used with your compression tester must have a similar volume
protruding into the combustion chamber to establish an accurate value.
Length of hose on the compression tester will affect the reading. The shorter
the hose length the more accurate your reading will be.
Because of these difficulties in measuring an absolute compression value, a
useful relative value can be achieved by testing your bike’s compression with
your own particular gauge after a new top end or when the bike is new so that
you know what your particular gauge reads on a ‘fresh’ engine. When it has
dropped to 90% of its original value the engine will be down on power and would
benefit from a rebuild. When it’s dropped to 80% it really needs rebuilt! Using the
table below will help you determine monitor the condition of your top end.
Example
Your Values
Engine is Fresh
Measured Value
110 psi
Engine Down on Power
Measured Value * 0.9
110 psi * 0.9 = 99 psi
Procedure for Compression Testing
1. Shut off the fuel petcock.
2. Install the compression gauge into the spark plug hole.
41
Engine NEEDS Rebuilt
Measured Value * 0.8
110 psi * 0.8 = 88 psi
3. Hold the throttle wide open, and kick repeatedly (approximately 20 times)
or until the gauge reading does not increase in value with each kick.
Base Gasket Selection
Tools required
17mm wrench
1mm flexible solder material
measurement calipers
When rebuilding the ‘top end’ of your Cobra motorcycle, care must be taken to
ensure the proper squish clearance. Squish clearance is defined as the minimum
distance between cylinder head and piston at TDC. There are negative effects of
either having too much or too little clearance. Since parts like the crank,
connecting rod, cylinder head, piston, and crankcases all have varying
tolerances, Cobra offers several different base gasket thickness’ to ensure that
you can always set the squish clearance of your engine to factory specifications.
For base gasket replacement use the code (see figure 31 for location) along with
the table below to reorder the correct thickness gasket.
Figure 31
Code
#
3
4
5
6
7
8
Supplied Base
Gasket Thickness
mm
inch
0.3
0.012
0.4
0.015
0.5
0.020
0.6
0.024
0.7
0.028
0.8
0.031
Cobra #
Part #
ZCMU0703
ZCKG0501
ZCMU0705
ZCMU0706
ZCMU0707
ZCMU0708
NOTE: Tolerances will affect the actual gasket thicknesses.
42
If top end parts are changed during the course of the maintenance, the squish
clearance should be measured, and possibly a different base gasket will be
required.
The easiest way to measure squish clearance is with 1mm to 1.5mm thick
flexible solder wire (available through most popular electronic stores). The
process is as follows:
Assemble the top end of the engine with either; 1) the crankcase stamp
recommended base gasket or, 2) if assembling with a new set of cases
assemble with a 0.4mm (0.015”) base gasket, and torque the head nuts to
the proper torque specifications leaving off the spark plug and ignition cover
(piston rings can be left off to ease of assembly).
Carefully insert the solder wire though the spark plug hole, into the cylinder
far enough such that the tip of the wire touches the left or right side cylinder
wall (not the front or back as the piston will rock more and give incorrect
measurement).
Hold the wire at this position and rotate the crankshaft, by the flywheel nut (or
kick lever) three revolutions to crush the solder wire to be measured.
CAUTION:
If you rotate the flywheel nut in a counterclockwise direction there is a risk of
loosening the nut.
Pull out the wire and measure the solder thickness at the thinnest location
near its tip accurately with the thin tips of calipers.
Adjust base gasket thickness as necessary to get the desired value.
Upon completion, your final assembly squish clearance should agree with the
chart below
43
Engine Removal
To service the bottom end/transmission, the engine must be removed from the
frame.
Tools required
10, 11, 13, 22 mm wrench
8, 10, 14, 17 & 19 mm sockets
3, 4 & 5 mm Allen wrench
7 mm nut driver, flat or Phillip, screwdriver for hose clamps
Spring remover
Flywheel / clutch puller (#MCMUTL68)
Clutch nut removal tool (#ECMU0078)
CFD gear stop (#EAMU0004)
Procedure
1. Remove the seat.
2. Turn of the fuel at the petcock and disconnect the fuel line.
3. Remove the tank (8 mm socket).
4. Remove the carburetor from the inlet (flat head or Phillips head
screwdriver, 7 mm nut driver).
5. Remove the silencer & pipe (spring remover, 8mm socket).
6. Locate a suitable container for the engine coolant and disconnect the
coolant lines connected to the engine (8 mm socket).
NOTE: If the coolant looks to be free of contaminates it may be reused.
7. Remove the master link from the chain.
8. Remove front engine mount bolt (13 mm socket, 6 mm hex key).
9. Remove the swingarm bolt (19mm socket).
NOTE: Only drive the swingarm bolt far enough to clear the engine, leave it
holding the one side of the swingarm to the frame
10. Remove the engine from the right side of the frame.
Complete Engine Disassembly Procedure
1. Remove the ignition cover (4mm Allen)
2. Remove the bolt from the water pump shaft (4mm Allen) and slide off the
belt cover and the water pump belt
3. Using a flywheel holding tool and 14mm socket remove the nut that
secures the flywheel.
4. Using the Cobra flywheel / clutch puller (#MCMUTL68), remove the
flywheel from the crankshaft.
5. Remove the stator (4mm Allen).
6. Remove the left hand thread nut holding the CFD to the transmission input
shaft using the CFD gear stop (#EAMU0004) and a 19mm socket.
7. Remove the clutch nut / starter gear that holds on the clutch using the
clutch nut removal tool (#ECMU0078).
8. With the Cobra flywheel / clutch puller (#MCMUTL68), remove the clutch
from the crankshaft (details in Clutch Service portion of this manual).
Top End Disassembly Procedure
1. Remove the cylinder head nuts (10mm).
2. Remove the cylinder head outer.
3. Remove the cylinder head insert.
INSPECTION NOTE:
Inspect the cylinder head for deposits and abrasions.
1. If there are deposits they should be removed
a. Black oily deposits (indicating a rich mixture or improper oil
type/quantity) can be removed with solvent
b. Crusty deposits (indicating dirt ingestion) can be removed with
solvent and may require some scraping.
2. Abrasions
a. Pitting or erosion indicates detonation and may require cylinder
head replacement, also
i.
Retard the ignition timing
ii.
Use a higher octane fuel
b. Missing chunks or indentations indicate broken hardware or
ingested items - replace the cylinder head.
4. Remove the cylinder.
INSPECTION NOTE:
Inspect the cylinder bore for abrasions, deposits, and missing coating.
1. If abrasions: scrapes, scratches, pitting, etc… are found, replace the
cylinder.
2. If deposits are all are found
a. Clean with muriatic acid.
b. Once the deposits are removed, inspect for abrasions and
missing surface coating.
i. If there are abrasions or missing coating, replace.
ii. If all looks well, the cylinder may be saved.
Muriatic acid can be dangerous. Follow the manufacturer’s instructions closely.
5. Remove the piston clip with a scribe.
6. Remove the piston pin with a piston pin remover
45
INSPECTION NOTE:
Inspect the piston for abrasions and deposits on the top and sides and clean or
replace as necessary.
INSPECTION NOTE:
Piston ring end gap should be between 0.006” (0.16 mm) and 0.020” (0.5 mm)
Splitting the Cases
1. Remove the fasteners holding the two halves of the crankcase together.
2. Separate the cases with a proper case splitting tool.
CAUTION:
Take caution when handling the crankshaft. It is the main power transfer to the
rest of the engine. If it is out of alignment, it will cause premature failure of your
bearings which can lead to serious damage to the cylinder as well as the rest of
the engine. Do not try to true the crank yourself. Truing the crank should be
done professionally.
CAUTION:
If you split the cases, check the gear tooth faces for chipping & signs of
fatigue.
Check the small needle bearings for fatigue. If the bearings are damaged,
the engine cases should be checked to make sure the needle-bearing casing
didn’t oblong the bearing hole in the case.
Needle bearings should be replaced every 2 months.
Engine Assembly
CAUTION:
For any seals that are to be installed, apply a light amount of grease to the seals’
ID, assembly lube on all bearings and a small amount of Loctite to the OD.
1.
2.
3.
4.
5.
6.
Press the three bearings into the respective holes in each case half.
Press in the crank seals such that the concave side faces the crank weights.
Press in the counter shaft seal (concave side faces inside of transmission)
Press in the water pump assembly
Tap both ways axially then verify easy rotation.
Inspect the crankshaft for proper true geometry
(no more than 0.002 “, 0.05mm, measured at
bearing journal area while supported from the
ends).
7. Insert case bolts with the proper lengths at the
locations shown.
8. Torque to 12Nm (105in-lb) in the pattern shown
here.
9. Trim away any excess gasket material
if necessary.
NOTE: Check engine mount holes for excess material that may cause problems
in engine installation.
10. Install the piston with new wrist pin bearing and, pin and clips.
CAUTION:
Be sure to install the piston such that the arrow on the top piston surface points
to the exhaust (front of bike/engine) and put assembly lube on the connecting rod
bearing.
11. Install the piston rings.
CAUTION:
Ring end gap should be no less than 0.006” (0.016mm) and no more than 0.020”
(0.5mm)
12. Install the base gasket.
CAUTION:
See base gasket selection at the beginning of service section.
13. Install the cylinder being sure that the piston rings are properly
aligned with the indexing pins.
CAUTION:
Never force the cylinder. If resistance is felt, determine the
problem and solve it. Once installed, slightly rotate the cylinder
back and forth insuring that the rings are properly seated.
14. Install cylinder head insert.
NOTE: A light application of silicone grease can help hold the
O-rings into position during assembly.
15. Install O-RINGs as shown in figure 33.
16. Install the cylinder head.
17. Install the washers (with flat side down) and nuts. Torque to
105 in-lb (12 Nm)
Figure 33
18. Install reed and intake manifold with new gasket. Torque to 55 in-lb. (6.2Nm).
CAUTION:
The intake manifold bolts will require being checked and torque values reset after
a few heat cycles.
19. Leak check the engine at 20 psi to ensure proper seal.
20. Install stator reinstalling the grommet and wires.
21. Install the rotor per Rotor Installation section, under the S3:
47
Ignition portion of this manual.
22. Install the water pump outlet pipe (apply Hi-Temp RTV silicon gasket maker
to the threads before assembly) before installing the clutch and rotate to a
vertical position with the engine resting on bench
23. Install the CFD.
24. Install the clutch per Clutch Installation section in this manual.
25. Install the coolant drain plug with copper washer (11 ft-lb, 15 Nm).
26. Make sure that the exhaust spacer is on the cylinder (53 in-lb, 6 Nm).
27. Install the spark plug with a fresh gasket (to apply the proper torque to the
spark plug when inserting, one must first screw the spark plug in until the
metal gasket ring causes resistance and then turn another 1/8 to ¼ turn).
Clutch
New in 2011, Cobra improved the clutch washer design. The new washer stacks
have taller springs but are overall shorter and have a single thin shim.
These new washer stacks are being double sorted at the factory. They are first
sorted by measured height. Secondly, each stack with bolt is sorted by measured
engagement force.
Because of this, we have been able to widen the range of stack heights that
provide an acceptable clutch ‘hit’. The stacks in each stack of three will measure
within 0.05mm (0.002”).
There are many variables in an automatic centrifugal clutch. These variables are
set to world class standards from the factory but will change over time as the
components wear, relax, and just plain get used.
Please see the Tuning Clutch portion of this manual for more helpful info.
Tools recommended for clutch service:
Universal clutch puller- a universal puller that pulls the clutch, main drive gear
and rotor. (Part # MCMUTL70).
5mm T-handle
Clutch nut removal tool (ECMU0078) & piston stop (MCMUTL03).
Cobra 3 Shoe Clutch Milk (Part # MCMUGF32).
CLUTCH REMOVAL:
1. Drain the engine transmission oil and remove the clutch cover.
2. Remove the clutch nut (not left hand thread) on the end of the crankshaft with
the clutch nut removal tool.
3. Attach the Universal Puller. There are three 6mm clutch puller holes located
on the ends of the center hub. (figures 30 & 31)
48
Figure 30
Figure 31 Clutch puller installation
CAUTION:
Do not use a jaw type puller or use the 6mm tapped holes as jackscrews or you
are likely damage the clutch or drum.
CAUTION:
It is possible to cause damage to the piston when using the piston stop. Care
must be used when removing and installing the clutch arbor and using the piston
stop.
4. If necessary apply heat to the center clutch hub.
CAUTION:
Do not heat the crankshaft threads or the aluminum shoes.
5. Keep tension on the puller as you are heating it.
The clutch will often pop off under tension from the puller and it will be very hot.
CLUTCH WASHER STACKUPS:
Once the clutch is removed, and cool to touch, carefully put it into a vice and
remove the center shoulder bolt out of each clutch shoe. You may have to heat
the center hub again to remove the bolts. Once you get a bolt loosened,
carefully remove it with the shoe and observe the way the spring washers are
stacked. Clean the washers and bolt if you intend to reuse.
The spring stacks in your Cobra clutch will contain 11 individual springs and flat
washer(s) configured as a 5 ½ stack. See figure 32. This clutch is designed such
that it reconfigured by the customer to achieve different clutch engagements ‘hits’
by changing washer counts and configurations.
CAUTION:
Generally reassemble the springs as you removed them from the engine or as
you received them from Cobra. If you are unsure call the Cobra Technical
Support Group 517 437 9100 and consult the experts.
49
CLUTCH ASSEMBLY REFERENCE DRAWING
REF # PART #
DESCRIPTION
1
CAMU0013
Set of three shoes, springs, bolts, flat washers & nuts
2
CAMU0010
Set Of three springs, washers, bolts & nuts
Not Shown CAMU0006
Complete assembled clutch (Arbor, shoes and washer stacks)
Figure 32 Some configuration of clutch spring stack. Each ‘spring’ stack contains multiple
springs (Belleville washers) - arranged into three, four, or five ‘flying saucers’, or turned away
against the flat washer(s). Shown is the 4 ½ stack..
Stack
5½
Total
Springs
11
Flying Saucers
or Cymbal Pairs
5
Turned Away
or Dish Stacked
1
Std. Flat
Washer(s)
VARIED
Clutch adjustment washers
Your Cobra comes stock with flat washer(s) at the bottom of the spring washer
stack. Cobra offers several thicknesses of thin adjustment washers that allow
clutch engagement tuning. Increasing the flat washer(s) thickness increases the
engine speed for clutch engagement thus increasing the abruptness of clutch
engagement (harder hit). Conversely, decreasing the flat washer(s) thickness
decreases the engine speed for clutch engagement thus decreasing the
abruptness of clutch engagement (softer hit).
Part #
Thickness mm (inch)
HKCSM015
HKCSM012
HKCSM008
HKCSM006
HKCSM005
HKCSM004
HKCSM003
HKCSM001
HKAM0022
1.5 (0.060)
1.2 (0.047)
0.8 (0.031)
0.6 (0.025)
0.5 (0.020)
0.4 (0.015)
0.25 (0.010)
0.12 (0.005)
CLUCTH SHIM KIT
NOTE: HKAM022 Clutch shim kit includes - 3 each .005”, .010”, .015” and .020”
shims along with 2 clutch to hub spacers and 2 thin clutch to hub spacers.
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Use the table above to order adjustment washers. Replace the stock washer with
the proper combination of adjustment washers that delivers the desired clutch hit.
CAUTION:
It is easy to prematurely damage the clutch and other engine components with
improper clutch adjustment. If you are unsure of how to adjust the clutch, contact
the Cobra Technical Support Group before making adjustments.
Clutch shoe wear:
This can be measured by the overall diameter of the shoes installed on the
arbor. This measurement should be greater than 80.5mm
If the clutch has been slipping and shows signs of glazing, it is best to replace
the shoes. We have found that once the shoes are glazed, even if deglazed
with emery paper or a file, the performance is reduced.
The best way to prevent glazing is by not gearing too high, changing the oil as
specified and by not blipping the throttle. Every time you blip the throttle, you
are working your clutch springs.
Clutch basket wear:
The internal diameter of a new clutch basket should measure ˜84.10mm.
Over time the clutch shoes will wear the internal surface down creating a
bigger ID and causing a later engagement. The maximum ID we recommend
to allow is 84.25mm.
CAUTION:
The clutch produces a tremendous amount of heat and when a rider is blipping
the throttle. This makes the clutch and clutch springs wear out quicker. This also
makes your engine tend to run hotter which decreases engine power. It is
important to train your rider NOT to be a throttle 'blipper'.
CAUTION:
Sludge build-up between the spring washers also keeps the clutch shoe from
engaging fully and this will cause the clutch to start to slip. So you will need to
clean the sludge out or just replace the spring washers and bolts with new ones.
How quickly this sludge builds up depends on how often you change your oil
and whether your rider is a throttle ‘blipper’.
CLUTCH ASSEMBLY:
1. Start with a new set of pre- assembled washer stacks or a cleaned,
reassembled set of washer stacks and bolts.
CAUTION:
It is also important that all three shoes are stacked the same. (See figure 32)
51
2. Clean the threads of the stack bolt and the clutch with brake cleaner
removing all old thread locking material.
3. Assemble the stacks and shoes on the arbor using high strength thread lock
material to the stack bolt and tighten to 12 ft-lb (16 N-m).
CAUTION:
Avoid allowing excess thread lock material to contact the spring washers and the
clutch or the clutch is likely to malfunction.
4. Clean the threads of the crank shaft and the clutch nut.
5. Install the clutch arbor on the crank. Making sure that the backing spacer in
place on the crank.
6. Apply high strength thread locking agent to the threads and install the clutch
nut and torque to 40 ft-lb (54Nm).
INSPECTION NOTE:
There must be in / out play in installed clutch, 0.4mm to 1.0 mm
(0.015” to 0.040”).
This should be adjusted with the ECMU0040T and ECMU0040
shims
Excess in/out will cause early crank seal failure.
A blue clutch drum is worn out from excessive slippage or improper
lubrication.
7.
Install the clutch cover tightening the bolts from inside out. (8 or 10 mm
socket, 5.8 ft-lb, 7.8 Nm).
NOTE: To ensure proper engagement of the kick gear with the starter nut,
tighten the six screws only to the point of being not extremely loose. Using one
hand rotate the kick lever to ½ stroke and hold while tightening the six screws
completely with the other hand.
8. Fill with oil (235 ml (8.0 oz) Cobra 3 Shoe Clutch Milk (Part # MCMUGF32).
Ignition
Stator care
Stator failure could result from running the bike hot. Following is a list of things
that will make your engine run hot.
1. The timing should not exceed the maximum specifications listed.
2. Improper carburetor jetting.
3. Improper spark plug heat range. Never run a hotter plug than the specified
spark plug.
4. Clutch slippage. See “CLUTCH” section for causes of slippage.
52
CAUTION:
Because of the amount of heat generated by the clutch and engine during
extended periods of riding, it is advisable to remove the ignition cover
afterward to allow the ignition to cool off. The heat transfers through the cases
and can damage the stator as it cools off because of lack of airflow around
the stator.
Ignition will overheat if the gap between the rotor and stator is not large
enough. There should be even clearance as the rotor rotates relative to the
stator.
Non-resistor spark plug caps should be used. Resistor caps will result in a
weaker spark that will reduce performance.
Make sure connections are free of dirt.
The proper ignition timing for this model of is at 0.040” before Top Dead Center
(that means 0.040” before the piston reaches the highest point of it’s travel in the
cylinder).
CAUTION:
Advancing the ignition timing will cause the engine to run hotter, in-turn causing
power loss, shortened clutch life, and possibly lead to premature stator failure,
and can also cause detonation which can lead to premature piston and ring
failure.
Tools recommended for timing service:
Compact motorcycle dial indicator (ECMU0079)
Universal clutch puller- a universal puller that pulls the clutch, main drive gear
and rotor. (Part # MCMUTL70).
TIMING YOUR IGNITION:
1. Remove the spark plug.
2. Insert the dial indicator into the spark plug hole.
3. Remove the four bolts from the ignition cover.
4. Remove the water pump belt from the rotor and water pump shaft.
5. Turn the crankshaft counterclockwise until it reaches top dead center.
53
6. Set the dial indicator to zero
7. Turn the crankshaft clockwise until the dial indicator reaches 0.040” (1.0mm)
from top dead center.
8. At this position the line on the rotor should align with the center of the stator
coil at 5 o’clock position on stator frame. If not loosen the three 5mm bolts to
adjust the stator.
0.040”
before
TDC
Figure 39, Lining up the line on the rotor
with the line on the stator.
Figure 40, Using a dial indicator to measure
piston height for setting ignition timing.
ROTOR INSTALLATION:
1. Torque the nut on the rotor to 30 ft-lb (45 Nm) with medium strength (blue)
thread locking agent.
2. Recheck the timing following the procedure of timing your ignition.
3. Install the water pump belt back on.
4. Bolt the ignition cover back on.
5. Put the spark plug back in, and firmly stick the spark plug cap onto the spark
plug.
Cooling System
Radiator fluid removal:
Remove the coolant drain plug (13mm bolt) on the front of the engine cases.
NOTE: Inspect the old coolant for evidence of oil, combustion byproducts (black
‘oil slick’ stuff) or other things that may indicate a problem.
54
Tools recommended for impeller service:
Flat head screwdriver
13mm- hex wrench
3mm hex key
4mm hex key
5mm hex key
8mm hex key
Water Pump Installation tool
MCMUTL09, 2010 and newer JR & King
MCMUTL08, 2009 and older JR models
Slide hammer with
fitting to thread into threads on end of shaft (M5x1.0)
single and double hook ends for removing plastic impeller
Dead blow hammer
COBRA IMPELLER SERVICE INSTRUCTIONS
1. Remove radiator cap and drain engine coolant as described above.
NOTE: If the impeller is damaged or broken completely back flush the coolant
system to ensure no solid pieces are in the system.
2. Remove ignition cover using a 4mm hex key (four places)
3. Stick a 3mm hex key in the water pump shaft cross hole, and remove belt
retainer screw using a 4mm hex key. (Figure 42 - item 1)
4. Remove belt retainer, water pump belt and water pump fan pulley.
5. Remove bearing retainer screw using a 3mm hex key.
6. Thread a slide hammer onto the end of the water pump shaft and remove the
assembly.
NOTE: It is quite common for the older plastic impellers to fall off the end of the
shaft during this step of the process if that is the case, then follow the steps at
the end of this section to remove the seal and impeller.
7. Clean any debris or particles from the bore and use some light emery cloth to
remove any scratches in the surface that the removal process may have
created.
8. Lubricate the bore with grease.
55
9. Prepare for assembly by installing the water pump assembly into the
assembly tool and align the tool with engine case making sure alignment pin
is in proper hole.
CAUTION:
Damage may occur if one attempts to install the water pump and the device is
not orientated correctly. If the tool does not sit flat against the cases, the
orientation of the tool to the engine is not correct. Make sure that the top
alignment pin is in the 2nd unthreaded hole, the bottom alignment pin is also in
the 2nd unthreaded hole, and that the relief for the stator bolt head is oriented
toward the stator.
10. Hold the installation tool firmly against the engine case and tap on the end of
the water pump shaft with a dead blow hammer until the insertion punch is
needed
11. Continue driving the assembly with the punch until the head is flush.
NOTE: The insertion punch is 0.010” (0.25mm) longer than the housing so as to
seat the water pump assembly just in from the case surface.
12. The assembly is installed properly when the retaining screw can be tightened
and it does not cause a bind on the spinning shaft (use medium strength
thread lock on the retainer screw).
NOTE: It may be necessary to tap the water pump shaft in (hammer) and out
(with slide hammer) to insure proper free operation of the shaft.
56
13. Reinstall the pulley, belt and fan cover using a 3mm hex key to stop the
rotation of the water pump assembly while tightening with medium strength
thread lock to 10 ft-lb (14Nm).
14. Reinstall the cover
NOTE: Refill the coolant system with 50/50 antifreeze-coolant / distilled water.
CAUTION:
Do not mix Propylene Glycol based coolant / antifreeze solutions with Ethylene
Glycol based coolant / antifreeze solutions.
Fuel & Air System
Carburetor
Tools recommended for carburetor service:
Small flat head screwdriver
WD-40
8mm socket
Your Cobra is equipped with an adjustable carburetor. Some fine-tuning may be
needed according to weather condition and altitude. Proper jetting is very
important for engine performance and engine life. Serious damage to the engine
can occur if not properly adjusted.
IDLE ADJUSTMENT:
On the left side of the carburetor, there are two adjustment screws. The larger
screw with the knurled head is the idle adjustment screw. To raise the idle, turn
the screw in clockwise (in 1/4 turn increments) and rev the engine after each
adjustment. To lower the idle, turn the screw counter-clockwise.
TOP END JETTING:
Indications that the engine is running too rich (too much fuel for the air) are:
Engine not revving out or blubbering at high RPMs.
Engine will not ‘clean out’
Wet or black spark plug
NOTE: Before changing jetting be sure that the air filter is properly cleaned and
has the usual amount of air filter oil. An overly dirty air filter can cause the engine
to run rich.
If the engine is running rich on the top end it should be leaned out. Leaning it out
can be done by:
1. Changing the main jet to a smaller number.
2. Raising the needle clip (this lowers the jet needle) one notch at a time on the
slide.
57
Indications that the engine is running too lean are:
Engine cutting out on top end.
Engine overheating and ultimately seizure.
White spark plug
CAUTION:
It is much safer to operate the engine slightly rich as opposed to slightly lean.
This is because an overly rich engine will just run poorly while an overly lean
engine will seize, potentially causing an expensive top end rebuild and a DNF.
To richen the carburetor:
1. Change the main jet one number at a time (larger).
2. Lower the needle clip (raising the jet needle) one notch at a time until the
engine starts to blubber on the top end, then move the clip back up one notch
or until you get the blubber out.
FUEL MIXTURE SCREW
The smaller brass screw that is towards the front of the engine is a fuel mixture
screw. This screw will also richen and lean your engine more on the bottom and
mid-range. In warmer conditions, turn the screw in. In colder conditions, turn the
screw out. Be sure to keep the carburetor very clean and make sure you don't
have water or dirt in the carburetor bowl. Use automotive carburetor cleaner or
WD-40 to clean the carburetor inside and out.
Cleaning the carburetor:
Clean the carburetor in a well-ventilated area, and take care that there is no
spark or flame anywhere near the working area; this includes any appliance with
a pilot light. Because of the danger of highly flammable liquids, do not use
gasoline or low flash-point solvent to clean the
carburetor.
1. Make sure the fuel is shut off and remove the
carburetor
2. Remove the carburetor.
3. Drain the fuel from the carburetor.
4. Disassemble the carburetor.
5. Immerse all the metal parts in a carburetor cleaning
solution.
6. After the parts are cleaned, dry them with
compressed air.
7. Blow out the fuel passages with compressed air.
8. Assemble the carburetor
9. Install the carburetor onto the motorcycle.
Figure 45 Proper carburetor top
installation And location of rectangular
slide indexing pin and vent elbows.
CAUTION:
The motorcycle will only operate properly if the carburetor top is installed properly
with the mounting screws, cable and choke knob oriented as shown in figure 45.
58
Reeds
The reeds must lay flat on the reed cage.
If the reed tips aren’t lying flat, replace them immediately.
The reeds must have a tight seal on the reed cage.
If the reed is damaged in any way, replace it. This means cracks, chips,
and ruptures. Anything abnormal, replace the reeds.
Take the reed cage out and hold it up to the light and look in through the cage. If
you see light between the reed pedals and the frame, then replace the reeds. If
you do not see light, then the reeds should be ok.
Exhaust
The pipe is a crucial element to a motorcycle. Any kinks, dents, or damage done
to the pipe will result in a major performance loss.
NOTE: Be sure to take the pipe off, and any carbon that may be built up.
Carbon build up is created from exhaust. Exhaust has oils in it, and the oils cling
to the walls of the inside of the pipe. Over a long period of time, the diameter of
the pipe will decrease, due to carbon build up. So it is essential to clear the
residue.
CAUTION:
It is important to repack the silencer.
repacked are:
The bike is louder than normal.
A loss of power.
59
Signs of your silencer needing to be
Rear wheel pullers
Disassembly:
1. Remove axle, and
back wheel
assembly.
2. Pull the rear wheel
pullers out of the
back of the swing
arm.
Figure 47
Rear wheel alignment:
Either
Accurately measure the distance from the swingarm pivot to the axle center
on each side or
From the rear of the bike, sight up through both sprockets to ensure that the
chain is running in a straight line (no bend in between or jog at either
sprocket).
Brakes
Check before each ride:
Make sure the brake does not have any leaks by holding the lever in while
checking hose connections.
Make sure the brake lever pressure is OK by pulling in on the lever and
ensuring full braking performance is achieved before the lever touches the
handlebar. If this is not the case, pump the lever several times until the lever
feels firm.
Always make sure the rotor and brake pads are free from oil and grease.
Clean the rotor with mild dish soap or alcohol. Contaminated pads must be
replaced.
Ensure that the brake caliper is centered over the brake rotor. It a correction
is needed, Cobra has thin brake shims to help make minor adjustments in
alignment.
Always leave adequate free-play in the lever or pedal.
CAUTION:
This brake system uses only DOT 4 or 5.1 brake fluid!
60
Front Forks
Tools recommended for front fork service:
Flat head screwdriver
Hammer
Pick
Seal driver MCMUTL02
9/16” (loose 14 mm) wrench
25mm wrench or socket
2.5 wt fork oil
FORK DISASSEMBLY PROCEDURES:
o
o
o
o
o
o
o
o
o
Using the 25mm wrench, remove the fork cap.
Drain the fork oil into a suitable container.
Disconnect the fork cap from the damper rod (9/16” wrench & 25mm wrench).
Disconnect the damper assembly from the fork leg by removing the large
aluminum bolt from the bottom of the fork leg (22mm wrench).
Pry the dust seal (swiper) from its position with a small screw driver.
Using a pick, remove the wire retaining ring holding the fork seals into place.
‘Pop’ the fork seal out by forcibly pulling on both ends of the fork tube
assembly, thus separating the inner from the outer tube.
Remove the bushings
Clean all components to be reused.
FORK ASSEMBLY PROCEDURES:
Figure 46
CAUTION:
Make sure all components are clean before assembly.
CAUTION:
Be sure to apply oil to the new fork seal and other components before installing.
1. Slide dust seal (swiper) (#6) onto lower fork leg.
2. Slide retaining ring (#5) onto lower fork leg.
3. CAREFULLY slide seal (#4) onto lower fork leg with spring facing away from
snap ring.
61
CAUTION:
It is helpful to cover the sharp corners of the fork leg with tape or thin plastic
before sliding on the new seal. Also take care that the inner lip is not folded over
when installing.
4. Slide bushing (#3) onto lower fork leg.
5. Install the glide ring into groove on lower fork leg.
6. Slide the bushing over the glide ring about 1/4" to hold the glide ring in the
groove.
7. Insert the lower leg assembly into the upper fork tube about 5-6".
8. Use a seal driver to drive the seal into the upper tube.
9. Install the retaining ring. Make sure it is properly seated in the groove.
10. Snap the dust seal (swiper) into the groove in the upper tube.
11. Reinstall the damper cartridge assembly to the fork leg. Secure the large bolt
with 22 mm wrench to 35 ft-lb with green thread locking agent.
12. Fill with 3.6 oz (107 ml) 2.5 wt fork oil should measure 6 mm (0.25”) above
the damper cartridge tube with spring removed. (This oil volume works out to
leave an oil height of 120mm from top of outer tube with forks collapsed,
damper rod down, and spring removed).
13. Install the fork spring
14. Connect the cartridge rod to the cap and tighten to 12 ft-lb (16 Nm).
CAUTION:
The damper rod is hollow and will break if the nut is over tightened (proper torque
is 12 ft-lb, 16 Nm).
Because of different rider weights, sizes and riding styles, we offer various
suspension options:
See Optional Components section of this manual for details on these and other
optional components for your Cobra Motorcycle.
Rear Shock
The rear shock is fully serviceable but it is recommended that only trained
professionals should service your shock. Contact Cobra for questions and
service of your CX50 SR shock.
62
Tuning
Clutch
There are performance characteristics to observe and things to measure.
1) Performance characteristics to observe
a) Clutch coming in too late
i) Engine rev’s to a high RPM before moving the motorcycle
ii) Clutch never fully engages on a reasonable straight stretch
iii) Basket turns blue in short amount of time
b) Clutch coming in too early
i) Motorcycle moves too soon when accelerating off idle
ii) Motorcycle moves but not with much power
iii) Clutch fully engages before the ‘power band’ kicks in
2) Things to measure that can have an effect
a) Spring washer configuration
b) Spring stack without flat washer
c) Thickness of flat washer
d) Individual spring washer thickness
e) Individual spring washer height
f) Effective bolt shoulder length
g) Shoe thickness (difficult to measure accurately - can only be approximated
by the size of the step where it sticks out of the basket)
h) Basket has worn and is too large
There is a relationship between observed characteristics and the things
that can be measured
If a clutch comes in too early, it means that clutch spring stack is not providing
enough force to keep the shoes from being thrown out to the clutch basket at
the proper time with the given shoes, basket, arbor, and bolt. This can be due to:
1. Clutch spring stack is to short
Wrong configuration
Sacked out (over stressed) washers
Too thin a flat shim in the stack
2. Spring rate too low (wrong configuration with proper stack height)
3. Clutch arbor shoulder bolt is too long
If a clutch comes in too late, it means that clutch spring stack is providing too
much force to keep the shoes from being thrown out to the clutch basket at the
proper time with the given shoes, basket, arbor, and bolt. This can be due to:
63
1. Clutch spring stack to tall
Wrong configuration
Too thick a flat shim in the stack
2. Spring rate too high (wrong configuration with proper stack height)
3. Clutch arbor shoulder bolt is too short
4. Clutch shoe material has worn too thin
5. Clutch basket has worn too much and is too large of a diameter
With the exceptions of component failures, generally two things will occur:
1) The clutch shoes will wear causing the clutch to engage later, and
2) The springs will sack causing the clutch to engage earlier.
Typically the springs will sack at a quicker rate than the shoes will wear, meaning
that an un-tampered clutch that worked fine will ultimately hit too early at some
time. When this occurs it is easily remedied with a new spring stack or a thicker
flat shim. Because the shoes have worn, a thinner flat washer may be needed
with the fresh new springs to allow proper clutch engagement.
One thing to remember:
If your clutch is hitting fine, don’t mess with it!
Some things to remember to aid clutch life
Change oil each ride
Gear to the low side
Avoid mud if possible
(Cut mud practice to 1 lap or none)
Stay on the gas (no throttle blipping)
Run more air pressure to allow wheels to spin (helps throttle steer)
Make sure wheels spin freely (no bent rotors, dragging brakes, chain too
tight, etc…)
Make sure the engines pulls cleanly and strong by having properly
maintained engine with correct ignition timing and carburetion.
With the exceptions of component failures, generally two things will occur:
The clutch shoes will wear causing the clutch to engage later, and
The springs will sack causing the clutch to engage earlier.
Typically the springs will sack at a quicker rate than the shoes will wear, meaning
that an un-tampered clutch that worked fine will ultimately hit too early at some
time. When this occurs it is easily remedied with a new spring stack or a thicker
flat shim. Because the shoes have worn, a thinner flat washer may be needed
with the fresh new springs to allow proper clutch engagement.
64
Effective length of the shoulder on the clutch arbor bolt (see Figure C1). Nominal
is 16.00mm (0.630”). As this decreases, the spring stack needs to decrease
equally. This can change due to the shoulder bolt ‘setting’ into the arbor (see C2)
Figure C1
Figure C2
If your effective shoulder length is off, or your shoes are worn, adjust the height
of your overall combined spring stack accordingly (i.e. if your effective shoulder
length is 0.5mm short of the 16.00 measurement, decrease the overall combined
spring stack height by 0.5mm, or if your shoes are worn by 0.5 mm, increase the
overall combined spring stack height by 0.5mm).
Frequently asked questions
Q: When should the springs be replaced?
A: When the clutch ‘hit’ occurs too early or too late.
Q: Should the clutch springs be replaced if the shoes wiggle on the arbor?
A: Not if the clutch is ‘hitting’ correctly. Don’t mess with it
Q: What is the acceptable tolerance on any of the measurements?
A: For the most part that does not matter. Suffice it to say that any efforts
to make the three shoes behave identically will make the best performing
clutch. Taking extra time to balance the three stacks (shims, springs,
bolts, etc…) to as close to the same length as you are willing to put effort
into will result in a better performing motorcycle.
Q: One of my two riders weighs 85 pounds and the other weighs 45 pounds.
Should I have their clutches adjusted differently because of their weight?
A: No, there is one best setting and it works for light or heavy riders.
Q: If my clutch basket changes color, should I replace it?
A: If it is blue or purple, replace it. If it is silver or brown, you are fine.
Cobra is now going to greater lengths to ensure that the clutch on your
motorcycle is performing the best possible from the shop and so it may have a
different clutch stack or shim washer from what you are used to. Please take
measurements for knowledge sake but don’t blindly restack washers to different
heights without first consulting the factory.
65
Gearing
For a bike with a centrifugal clutch, it’s better to be geared too low than too
high.
Condition
Gear Taller Gear Lower
Mud
What happens with improper
gearing?
Sand
Poor performance
Hills
Not enough top end
speed
Hard Pack
No snap
Throttle Blipper (novice)*
Over heat clutch
Premature failure of
engine seals, bearings, & electronics
High clutch wear
*It may be helpful to set up the clutch to hit early for smooth power delivery
Front Sprocket
15
15
15
14
15
14
15
14
15
13
14
15
13
14
15
13
14
15
13
14
15
13
14
13
14
13
14
13
13
13
Rear Sprocket
Gear Ratio
33
34
35
33
36
34
37
35
38
33
36
39
34
37
40
35
38
41
36
39
42
37
40
38
41
39
42
40
41
42
2.20
2.27
2.33
2.36
2.40
2.43
2.47
2.50
2.53
2.54
2.57
2.60
2.62
2.64
2.67
2.69
2.71
2.73
2.77
2.79
2.80
2.85
2.86
2.92
2.93
3.00
3.00
3.08
3.15
3.23
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*
Suspension
Adjustment
1. Front forks
1.1. Fork oil
1.1.1. Oil type
1.1.1.1. Heavier weight oil – more damping – slower responding
1.1.1.2. Lighter weight oil – less damping – quicker responding
1.1.2. Oil quantity / level
1.1.2.1. Greater quantity / higher level – greater bottoming
resistance, stiffer near the end of the travel.
1.1.2.2. Smaller quantity / lower level – less bottoming resistance,
less stiff near the end of the travel.
1.2. Fork spring
1.2.1. Stiffer spring (higher spring rate) – stiffer throughout the travel.
1.2.2. Less stiff spring (lower spring rate) – less stiff throughout the travel.
1.3. Gas pressure – always bleed off any pressure.
1.4. Fork height
1.4.1. Rise in clamps for quicker turning.
1.4.2. Lower in clamps for improved straight line stability.
1.5. Compression damping
1.5.1. Harder (more damping, slower) – adds resistance to the
suspension motion when the suspension is compressing.
1.5.2. Softer (less damping, quicker) – reduces resistance to the
suspension motion when the suspension is compressing
1.6. Rebound damping
1.6.1. Harder (more damping, slower) – adds resistance to the
suspension motion when the suspension is returning to full length.
1.6.2. Softer (less damping, quicker) - reduces resistance to the
suspension motion when the suspension is returning to full length
2. Rear shock
2.1. Preload adjustment
2.1.1. More preload (greater distance) – less race sag.
2.1.2. Less preload (smaller distance) – more race sag.
2.2. Shock spring
2.2.1. Stiffer spring – stiffer throughout the travel.
2.2.2. Less stiff spring – less stiff throughout the travel.
2.3. Compression damping
2.3.1. Harder (more damping, slower) – adds resistance to the
suspension motion when the suspension is compressing.
2.3.2. Softer (less damping, quicker) – reduces resistance to the
suspension motion when the suspension is compressing.
2.4. Rebound damping
2.4.1. Harder (more damping, slower) – adds resistance to the
suspension motion when the suspension is returning to full length.
2.4.2. Softer (less damping, quicker) - reduces resistance to the
suspension motion when the suspension is returning to full length
67
Front Fork Operation
The front suspension on the CX50SR works under the principals of hydraulic damping,
and it features full adjustability to help tune the fork to meet each rider’s needs. The
CARD fork contains MXT ‘Smart Leg’ technology that provides very progressive
operation; allowing a small bike to perform well on track surfaces ripped up by larger
machines.
The key to Smart Leg technology is to understand that each leg has a different
role. The brake side leg features a conventional open cartridge. This cartridge
handles both standard compression and rebound damping duties. Rebound
damping is adjustable on the fork cap, and compression damping is adjusted at
the bottom of the fork. The other leg (the Smart Leg) has no rebound damping,
and it contains both a speed sensitive compression damping mechanism as well
as a position sensitive one. This design allows for a firm low speed response,
controlling rapid chassis pitch, which promotes stability and control. The fork
produces significantly less mid and high-speed compression until it travels into
the progressive / speed sensitive portion of the smart leg. The speed sensitive
compression component is adjustable at the top of the fork.
The combination of the Smart Leg and the conventional leg allows the fork to be
very supple throughout all low amplitude operation and yet take punishing hits;
producing a progressively increasing damping rate that slows the forks
movement as it approaches full bottom. Therefore, the Smart Leg also acts as a
hydraulic bottoming control device. Finally, the large degree of adjustability in
both legs allows the fork to be tuned to meet each rider’s size, ability, and type of
riding they do (motocross, off-road, flat track, etc).
Fork Damping Adjustments
Tools required
Small flat blade screwdriver
The speed at which the fork rebounds can be adjusted
at the top of the conventional leg. Turning the
adjustment screw clockwise slows the rate at which
the fork extends after being compressed, and likewise,
turning the screw counter-clockwise returns the leg to
its extended position faster. As shown in the figure, ‘S’
(slower) and ‘F’ (faster) are etched into the cap as an
adjustment guide.
At the base of the conventional leg is another adjustment
screw that controls the amount of compression damping.
Turning this screw clockwise increases damping and turning
68
it counter-clockwise will decrease it. This is illustrated by the “HARD” and “SOFT”
in the figure at the right.
The Smart Leg cap is labeled “Speed Sensitive
Bottoming Control”, and this adjuster provides a range
of control over how progressive the fork feels. Turning
the screw clockwise increases the fork’s resistance to
bottoming, while turning the screw counter-clockwise
decreases it. On the track, this effect will be felt on
sections where the fork is forced to move very quickly
such as on harsh landings or when traversing sharp
edged bumps.
Symptom
Rear end feels stiff on small bumps
Rear end ‘sways’ on straights
Bike tends to jump ‘rear end high’
Bike tends to jump ‘rear end low’
Frequent rear end bottoming
Bottoms after end of continuous bumps
Rear end ‘kicks’ over square edge bumps
Action
Softer compression damping
Harder compression damping
Harder rebound damping
Softer rebound damping
Harder compression damping
Softer rebound damping
1) Harder rebound, 2) Softer
Compression
Rear Shock Adjustments
Always start with standard settings and make damping changes in no more than
two click increments and only make one change at a time.
Symptom
Rear end feels stiff on small bumps
Rear end ‘sways’ on straights
Bike tends to jump ‘rear end high’
Bike tends to jump ‘rear end low’
Frequent rear end bottoming
Bottoms after end of continuous bumps
Rear end ‘kicks’ over square edge bumps
Rear end feels stiff under acceleration
bumps.
Proactive Suspension Adjustments
69
Action
Softer Low Speed Compression
Damping
Harder Low Speed Compression
Damping
Harder High Speed Compression
Softer High Speed Compression
Harder Compression Damping
Softer rebound damping
1) Harder rebound, 2) Softer Low and
High Speed Compression
Softer Rebound and/or Stiffer Low
Speed Compression Damping
Once you have the suspension adjusted for decent overall feel, you can make
proactive adjustments when faced with different racing conditions.
Situation
Sand track
Sand track
Long fast track
Tight slow track
Mud track
Actions
Lower the rear end (increase race sag).
Stiffer compression and rebound damping.
Lower the forks in the clamps by 3 mm.
Raise the forks in the clamps by 3 mm.
Lower the bike if the rider has difficulties
touching the ground.
Shock preload
Loosen the set screw and turn the spring perch in
full turn increments to get the desired sag settings.
NOTE:
Always leave the spring perch rotated in such
position so that the set screw is easily accessible.
Shock Damping
11. Adjustment of rebound damping
12. Adjustment of compression damping
Carburetion
Although your Cobra is sent from the factory with the carburetor jetted for optimal
performance, you may find it necessary to adjustment your particular jetting due
to current weather conditions, altitude, fuel variations, and/or engine
modifications.
70
CAUTION:
Proper jetting is very important for engine performance and engine life.
Symptoms of improper jetting are listed below.
Symptoms of incorrect oil or oil / fuel ratio
o Poor acceleration
o Misfire at low engine speeds
o Excessive smoke
o Spark plug fouling
o Excessive black oil dripping from exhaust system
Symptoms of too rich a fuel mixture
o Poor acceleration
o Engine will not ‘rev’ out, blubbers on top
o Misfire at low engine speeds
o Excessive smoke
o Spark plug fouling
o Wet, black, or overly dark spark plug (when removed for inspection)
Symptoms of too lean a fuel mixture
o Pinging or rattling
o Erratic acceleration
o Same actions as running out of fuel
o High engine temperature
o White spark plug (when removed for inspection)
NOTE: When inspecting the spark plug to evaluate jetting, a properly jetted
machine will produce a spark plug that is dry and light tan in color.
Environmental and altitude related mixture adjustments
Condition
Mixture will be
Required adjustment
Cold air
Leaner
Richer
Warm air
Richer
Leaner
Dry air
Leaner
Richer
Very humid air
Richer
Leaner
Low altitude
Standard
None
High altitude
Richer
Leaner
Low barometric pressure
Richer
Leaner
High barometric pressure
Leaner
Richer
NOTE: Before making any carburetor jetting changes verify that:
o You are using the proper fuel and oil
o The fuel is fresh and uncontaminated
o The oil and fuel have been mixed in the proper ratio
o The carburetor is clean (no plugged jets)
o The air filter is properly clean and oiled
o The float height is within proper specification (proper measuring technique
is described later in this section)
71
NOTE: Perform all jetting changes on a motorcycle that has been warmed up to
proper operating temperature.
The carburetor on your Cobra motorcycle is quite adjustable. Figure 59 shows
its range of adjustment and in particular what adjustable component affects what
range of operation (specifically throttle position).
Figure 59
FUEL SCREW ADJUSTMENT: Adjust for maximum idle speed
The fuel adjustment screw is located on the left side of the carburetor. It is the
smaller of the two adjustment screws and requires the use of a small flat blade
screwdriver for adjustment. After adjusting for maximum idle speed, use the idle
screw to adjust the desired idle speed.
NOTE: If the fuel screw requires more than 3 turns out, replace the pilot jet for
one that is one size richer (larger number) then re-adjust the fuel screw.
IDLE ADJUSTMENT:
Adjust for desired idle speed
The idle speed screw is located on the left side of the carburetor. It is the larger
of the two screws on the side of the carburetor and is unique with its knurled
head for easy fingertip adjustment. To raise the idle, turn the screw in, clockwise,
(in 1/4 turn increments) and rev the engine after each adjustment. To lower the
idle, turn the screw counter-clockwise.
TOP END JETTING:
Adjust for clean full throttle acceleration
Jet your top end (main jet) based on the acceleration of your Cobra Motorcycle
on the longest straight at the track. Observe any of the lean or rich symptoms
(spark plug appearance and bike performance) listed above and change your
jetting accordingly.
PART THROTTLE
Adjust for desired acceleration
Using an area of the track that allows the rider to operate and mid throttle and
transition (accelerate, or ‘roll on’) from closed, or mostly closed throttle, to a
larger throttle opening. Observe the rich and lean symptoms listed above.
Adjust the jet needle position by moving the clip from its current position (move
the clip higher on the needle to make the bike run leaner, or move the clip lower
on the needle to make the bike run richer) to one higher or lower.
72
Troubleshooting
1) Engine not behaving properly
a) Carburetor top is installed backwards (happens a lot)
b) The carburetor slide indexing pin is missing
c) Wrong spark plug installed (8339 Champion to be used on ’04 or later & no
mods)
d) Needle clip is on top of plastic not below
e) Air leak – find where with carb cleaner or similar
f)
Ground wire or ignition leads have fault
2) Engine is down on power
a) Clutch engagement is not set properly
b) Jetting is incorrect
c) Silencer needs repacked
d) Exhaust pipe
i)
Has excess carbon buildup
ii) Has large dent in it
e) Compression is low
i)
Piston
ii) Rings
f)
Reeds are damaged
g) Ignition timing is incorrect
3) Engine is excessively loud
a) Silencer needs to be repacked
4) Engine cuts out at high RPMs
a) Stator bad
b) Carburetor diffuser plate upside down (install like a skirt)
c) Plugged fuel petcock
d) Silencer core tube broken
5) Engine won’t start
a) Fuel
i)
None in tank
ii) Is sour or bad
b) Carburetor is dirty
c) Ignition
73
i)
Spark plug fouled
ii) Wrong spark plug installed (8339 Champion to be used on ’04 or later & no
mods)
iii) Spark plug cap off
iv) Engine Shut-off ‘kill’ switch is shorted
v) Bad electrical ground
vi) Stator winding damaged
d) Exhaust is plugged
6) Overheating
a) Bad stator
b) Water pump pulleys or belt broken
c) Water pump impeller broken or bolt out
d) Jetting too lean
e) Too much throttle blipping
f) Too high gearing
g) Kinked radiator hose
h) Rear brake dragging
i)
Chain too tight
j)
Air leak
7) Engine won’t idle
a) Idle knob needs adjusted
b) Air leak
c) Carburetor jets are dirty
74
Index
Air Filter Maintenance ................... 14
Frame Parts .................................. 31
Airbox
Frictional Drive .............................. 16
Parts .......................................... 18
Front Brake
Bars and Controls ......................... 19
Parts .......................................... 33
Base Gasket Selection.................. 42
Front Wheel Parts ......................... 34
Break-In .......................................... 6
Fuel System
Carburetor
Service....................................... 57
Parts .......................................... 20
Hardware and Fasteners
Service ...................................... 57
Frame ........................................ 31
Specifications .............................. 4
Plastic ........................................ 35
Tuning ....................................... 70
Ignition
Timing ........................................ 53
CFD Cobra Frictional Drive ........... 16
Chain
Jetting
Adjustment ................................ 11
How To ...................................... 57
Chassis
Stock............................................ 4
Specification ................................ 4
Troubleshooting ......................... 71
Clutch Lubricant
Lubrication
Replacing .................................. 10
Recommended ............................ 4
Compression test .......................... 41
Maintenance
Cooling System ............................. 54
Schedule...................................... 8
Engine
Tips .............................................. 8
Specifications .............................. 4
Oil
Exhaust ......................................... 59
Recommended ............................ 4
Parts .......................................... 27
Optional Components...................... 5
Fork
Parts
Adjustments ............................ 68
Airbox and Filter ........................ 18
Operation ................................. 68
Bars and Controls ...................... 19
Fork oil replacement ............. 15, 16
Bottom End & Transmission ...... 23
Forks
Carburetor ................................. 20
Parts .......................................... 28
Coolant System ......................... 21
75
Engine ....................................... 23
Parts .................................... 38, 39
Exhaust ..................................... 27
Slip Clutch ..................................... 16
Forks ......................................... 28
Spark Plug
Frame ........................................ 31
Recommended ............................ 4
Front Brake ............................... 33
Specifications .................................. 4
Front Wheel ............................... 34
torque values ............................... 5
Inlet ........................................... 18
Starting ............................................ 7
Plastic & Seat ............................ 35
Suspension
Rear Brake ................................ 36
Adjustment................................. 67
Rear Wheel ............................... 37
Swingarm Parts ............................. 40
Shock .................................. 38, 39
Top End
Swingarm .................................. 40
Parts .......................................... 26
Top End..................................... 26
Service....................................... 41
Triple Clamps ............................ 28
Torque Values ................................. 5
Transmission
Plastic & Seat Parts ...................... 35
Specifications .............................. 4
Pullers .......................................... 60
Transmission Lubricant
Rear Brake
Adjustment ................................ 11
Replacing................................... 10
Parts .......................................... 36
Troubleshooting ............................ 73
Jetting ........................................ 71
Rear Wheel
Parts .......................................... 37
VIN reading ..................................... 8
Pullers ...................................... 60
WARNING ....................................... 1
Wheels
Reeds ........................................... 59
Service....................................... 59
Shock
Adjustments ............................ 69
76