Cobra Moto CX50 JR 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.
MCCJ2011.1
Table of Contents
General Information ......................................................................................................... 4
Specifications - General.............................................................................................. 4
Specifications - Torque Values .................................................................................. 5
Optional Components.................................................................................................. 5
Break-In Procedure...................................................................................................... 6
Starting Procedure ....................................................................................................... 7
Maintenance ..................................................................................................................... 8
Tips................................................................................................................................. 8
Schedule........................................................................................................................ 9
Replacing Transmission / Clutch Lubricant ...........................................................10
Proper Chain adjustment ..........................................................................................11
Air Filter Cleaning .......................................................................................................11
Fork Oil Replacement................................................................................................12
Cobra Frictional Drive (CFD)....................................................................................13
Parts .................................................................................................................................15
Parts – Airbox and Inlet System ..............................................................................15
Parts – Bars and Controls .........................................................................................16
Parts - Carburetor ......................................................................................................17
Parts – Coolant System ............................................................................................18
Parts – Electrical System ..........................................................................................19
Parts – Engine – Bottom End and Transmission ..................................................20
Parts – Engine Clutch and Kicker............................................................................21
Parts – Engine – Water Pump .................................................................................22
Parts – Engine – Top End .........................................................................................23
Parts – Exhaust System............................................................................................24
Parts – Forks & Triple Clamps .................................................................................25
Parts – Forks – Leg Assembly.................................................................................26
Parts – Frame – Mounting Hardware I ...................................................................27
Parts – Frame – Mounting Hardware II ..................................................................28
Parts – Front Brakes..................................................................................................29
Parts – Front Wheel...................................................................................................30
Parts – Plastic & Seat................................................................................................31
2
Parts – Rear Brake ....................................................................................................32
Parts – Rear Wheel ...................................................................................................33
Parts – Shock .............................................................................................................34
Parts – Swingarm Assembly ....................................................................................35
Service .............................................................................................................................36
Engine Service ...........................................................................................................36
Base Gasket Selection..........................................................................................37
Engine Removal .....................................................................................................39
Complete Engine Disassembly Procedure ........................................................39
Top End Disassembly Procedure ........................................................................40
Splitting the Cases .................................................................................................41
Engine Assembly ...................................................................................................41
Clutch...........................................................................................................................43
Clutch Removal: .....................................................................................................45
Clutch Assembly: ...................................................................................................48
Ignition .........................................................................................................................49
Cooling System ..........................................................................................................51
Radiator fluid removal: ..........................................................................................51
Fuel & Air System ......................................................................................................54
Carburetor ...............................................................................................................54
Reeds.......................................................................................................................56
Exhaust........................................................................................................................57
Wheels & Tires ...........................................................................................................57
Rear wheel pullers .................................................................................................57
Tuning ..............................................................................................................................58
Clutch...........................................................................................................................58
Gearing ........................................................................................................................59
Suspension .................................................................................................................61
Rear shock ..............................................................................................................62
Front Forks ..............................................................................................................62
Carburetion .................................................................................................................63
Troubleshooting ..............................................................................................................66
Index.................................................................................................................................68
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
Collapsed fork oil height
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
Champion 8339-1, 8332-1 hotter, 8904-1 colder
0.023” – 0.025” (0.58 – 0.64 mm)
0.035” (0.9 mm) Before Top Dead Center (BTDC)
High octane pump gasoline
Motul 800 2T Off Road
Motul 800 2T Off Road, 50:1 to 63:1
All other premix oil at 32:1 to 40:1
14 mm Dell’Orto
55 / 92
16mm + 0.5mm (0.63” + 0.020”)
Single / Cobra 3 shoe
13/37T or 14/38 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)
Marzocchi 32mm
SAE 20 weight
200 ml (6.8 oz) oil change, 220 ml (7.4 oz) rebuild
70 mm (2.75”) spring in, no spacer
4
Specifications - Torque Values
Torque Value
ft-lb
in-lb
Nm
Cylinder head nuts
8.8
105
12
Crankcase bolts
8.8
105
12
Spark plug
(SP)
(SP)
(SP)
Stator bolts
2.1
25
2.8
Stator cover bolts
1.7
20
2.3
Clutch cover bolts
5.8
70
7.9
Clutch nut
40
480
54
Clutch bolts
12
144
16
CFD nut
55
664
75
Engine mount bolts
22
265
30
Swingarm pivot
21
250
28
Shock bolt
35
420
47
Water pump impeller 3.6
44
5
Intake manifold bolts 4.6
55
6.2
Ignition rotor nut
40
480
54
Rear sprocket bolts
18
216
24
Axle nuts
25
300
34
* Apply high strength thread locking agent when installing.
**Apply medium strength thread locking agent when installing.
Fastener
Size & Remarks
M6 X 1.0
M6 x 1.0
M14 x 1.25
M5 X 0.8**
M4 X 0.75
M6 X 1.0
10 x 1.25*
M6 x 1.0*
½” x 20 LHT*
M8 X 1.25
M14 X 2.0
M10 x 1.5**
M5 x 0.8*
M6 X 1.0
M10 x 1.25*
M7 X 1.0**
M12 X 1.25
(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.
Optional Components
Call your dealer, or the factory, for details
• Carburetor jets
• Sprockets
• Suspension Springs
Weight of Rider (lb)
Fork Spring
Shock Spring
Less than 38 (light)
KCMZ0012A
(12 lb/in, 2.10 N/mm)
SCMUOH04 (275 lb/in) red
38 – 45 (std)
KCMZ0012
(14 lb/in, 2.45 N/mm)
SCMUOH05 (285 lb/in)
yellow
KCMZ0012B
(16 lb/in, 2.80 N/mm)
Tall Seat (Not AMA Legal)
Bar Risers
Wide Foot pegs
SCMUOH06 (295 lb/in)
white
46 to 55 (stiff)
•
•
•
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 Motul 800 T2 Off Road premix oil with high
octane pump gas mixed at 50:1 (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.
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:
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.
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. Motul 800 2T Off Road 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
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
8
8.
cases and can damage the stator as it cools off because of lack of airflow
around the stator.
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 every 10 hours of riding.
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
•
•
•
Between each ride
o Check that the air filter is cleaned and oiled.
o Insure the smooth operation of the throttle cable.
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 it’s safe limits.
o Check the rims for signs of stress, like cracks around the rim, spokes
and hub.
Every 2 hours of operation
o Replace the transmission oil.
Every 10 hours of operation
o Replace the fork oil.
9
o Have the shock oil replaced by a Certified Cobra Mechanic or a
suspension specialist.
Replacing Transmission / Clutch Lubricant
Minimum of 235 ml (8 oz) Cobra Venom 3 Shoe Clutch Milk (Part #
MCMUGF32). Up to 350ml (12 oz) can be applied without hurting performance.
Tools needed:
• 8mm allen wrench
Procedure:
1. Begin this procedure with a bike that has been ridden more than 5 minutes
but less than 10 minutes.
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:
Applying 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
10
# MCMUGF32) was formulated to provide superior lubrication and cooling
capability over extended periods of time and is the recommended lubricant for
your Cobra motorcycle.
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 35mm (13/8”) free
movement behind the chain
block with no load on the bike.
(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 it’s 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
Figure 2
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.
11
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 water-resistant 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 8).
Figure 8
NOTE:
Make sure you change or clean your filter after each ride.
Fork Oil Replacement
Tools required
•
•
•
5 & 6 mm Allen wrench
19 mm wrench or socket (two required)
Spring clip remover
Disassembly
1. Remove the front wheel.
2. Remove the fork legs from the triple clamps.
3. Perform the following on one leg at a time.
4. Using your hands, remove the black rubber plug from the top of the fork leg
exposing the white plastic cap.
12
5. Secure the fork leg assembly in a vice by gripping the leg across the flats
through which the axle bolt goes through.
6. Depress the white plastic cap inwards (down) and remove the wire spring clip
from its groove.
7. Remove the white cap, the fork spring preload sleeve, and the fork spring.
NOTE: Depressing the fork leg will facilitate removing the white cap.
8. The fork can now be turned upside down and drained.
Assembly
1. Fill the leg with 200 cc (6.8 oz) 20 wt fork oil.
2. Standard fork oil level is 70 mm (2.75”) from the top edge with the fork
collapsed.
NOTE: Remove the preload sleeve but leave the spring in for the measurement.
3. Install the preload sleeve.
4. Install and depress the white cap while installing the spring clip.
5. Fork may be reinstalled.
Cobra Frictional Drive (CFD)
The Cobra Frictional Drive (CFD) is essentially a 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’ between a minimum torque value,
and a maximum torque value. The slip torque of the CFD should be checked
every 5 hours of operation.
The blue CFD nut has left hand threads which
require clock-wise rotation to loosen.
Slip Torque
Minimum
Maximum
Ft-lb
55
92
N-m
75
125
To properly measure the torque of the CFD (Cobra
Frictional Drive), access the slip clutch by draining
the oil and removing the cover exposing the CFD.
Next, brace the CFD gear from turning with a
suitable device (Cobra tool EAMU0004 or similar).
Using a beam style torque wrench, turn the torque
wrench counter clockwise and observe the torque
measurement when the shaft slips relative to the
gear. Using a preset value torque wrench, adjust
13
the setting 55 ft-lb (75 Nm) and observe whether the wrench clicks first or the
shaft slips. If the shaft slips first, the slip torque is below 55 ft-lb and the CFD
needs servicing. If the wrench clicks first, the CFD is of acceptable value.
NOTE
To loosen and tighten the blue CFD nut, use a strong wooden object (large
hammer handle) through the spokes of the rear wheel as a brace against the
swingarm to stop transmission shaft rotation.
14
Parts
Parts – Airbox and Inlet System
Figure 7
Airbox and Inlet System
REF #
1
2
Not Shown
4
5
6
7
8
Not Shown
Not Shown
Not Shown
9
10
11
12
13
14
15
16
PART #
ZCMU0132
ECKG0202
ECKG0205
ECKG0203
HCWF0601
HCBC0625
MCKGHO04
RACM0002
FCMU0026
MCMUCL04
RCMU0022
FCMU0019
RCCM1301
MCKGHO01
RCMU0403
RCMU0405
HCBB0612
RCMU1407
RCMU0406
DESCRIPTION
GASKET – REED TO CYLINDER
REED BLOCK ASSEMBLY
REEDS REPLACEMENT
INLET MANIFOLD
6MM FLAT WASHER
M6X25 SOCKET HEAD CAP SCREW
HOSE CLAMP – CARBURETOR TO MANIFOLD
CARBURETOR 14MM
FUEL LINE 5”
HOSE CLAMPS – FUEL LINE
VENT HOSE
THROTTLE CABLE
VELOCITY STACK
HOSE CLAMP – AIR BOOT TO CARBURETOR
AIR FILTER WITH BOOT
AIR BOX – CM
M6X12 BUTTON HEAD BOLT (2 REQ’D)
BRACKET – MUD FLAP
MUD FLAP – CM
15
Parts – Bars and Controls
Figure 8
Bars and Controls
REF #
1
2
3
4
5
6
7
8
9
10
PART #
FCMU0066
FCMU0068
TCMU0008
FCMU0019
FCMU0033
KCMZ0001
KCMZ0003
KCMZ0002
TCMU0019
BCKG0024
DESCRIPTION
THROTTLE ASSEMBLY
THROTTLE COVER
GRIPS (SET OF TWO)
THROTTLE CABLE
KILL SWITCH ASSEMBLY
M8X50 SOCKET HEAD CAP SCREW (4 REQ’D)
LOWER HANDLE BAR CLAMP (2 REQ’D)
TOP HANDLE BAR CLAMP (2 REQ’D)
HANDLEBAR - ALUMINUM
BRAKE PERCH ASSY W/LEVER & BALL
FOR FRONT BRAKE ACCESSORIES SEE “FRONT BRAKE” SECTION
16
Parts - Carburetor
Carburetor
REF. #
Figure 9
1
2
3
4
PART #
RCCM0001
RCMU0305
RCMU0601
RCMU00
RCMU00xx
DESCRIPTION
COMPLETE CARBURETOR 14MM
CARB SLIDE
NEEDLE
ATOMIZER AU2.62
MAIN JET, xx denotes size
5
RCMU00xx
PILOT JET, xx denotes size
6
7
8
9
11
12
RCMU0301
RCMU0102
RCMU0003
RCMU0006
RCMU0106
CHOKE JET
FLOAT
RUBBER CABLE CAP SEAL
CABLE ADJUSTOR
TOP CARB SCREW
CARB TOP
13
ZCMU0007
TOP CARB GASKET
14
RCMU0004
SLIDE SPRING
15
RCMU0028
NEEDLE RETAINER PLATE
16
RCMU0007
NEEDLE CLIP
17
RCMU0204
CHOKE ASS’Y. 2001 CM
20
RCMU0009
FUEL MIXTURE SCREW
21
RCMU0011
IDLE ADJUSTMENT SCREW
25
RCMU0103
FLOAT BOWL GASKET
26
RCMU0107
FLOAT NEEDLE
27
RCMU0012
DIFFUSER
28
RCMU0016
FLOAT RETAINER PIN
29
RCMU0108
FLOAT BOWL
30
HCWF0401
WASHER 4MM FLAT
31
RCMU0201
BOTTOM FLOAT SCREW
Not Shown RCCM1301
VELOCITY STACK – 05 style
Not Shown RCCM0314
14MM CARB RESTRICTOR
Not Shown FCMU0026
FUEL LINE 5”
Not Shown MCMUCL04
Not Shown RCMU0022
HOSE CLAMPS – FUEL LINE
CARB VENT HOSE 2” EACH
17
Parts – Coolant System
Coolant System
REF #
1
NOT SHOWN
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
KIT
PART #
FCCJ0004
FCMU0022
MCMUHO02
MCMUCL07
EACJ0001
HCBC0608
HCNL0601
MCKGGR00
MCCMHO01
TCCJ0001
FCMU0049
MCMUCL05
ECHA0109
HCBC0665
FCCJ0002
HCCN0000
HCBC0501
FKMU0001
DESCRIPTION
RADIATOR WITH CAP
CAP, 1.2 BAR
RADIATOR HOSE LEFT
HOSE CLAMP
MOUNTING BRACKET – RADIATOR BOTTOM
M6X55 SOCKET HEAD CAP SCREW
6MM 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)
M6X65 SOCKET HEAD CAP SCREW
LOUVER SET (LEFT AND RIGHT)
5MM CLIP NUT
M5X12 SHCS
RADIATOR SERVICE REPLACEMENT KIT (INCLUDES HARDWARE)
18
Parts – Electrical System
Electrical System
REF #
1
2
2H
2C
3
4
NOT SHOWN
NOT SHOWN
NOT SHOWN
6
7
8
9
10
NOT SHOWN
11
12
13
14
15
PART #
IAMU0005
ECMU0065
ECMU0067
ECMU0066
FCMU0033
HCBC0516
HCWF0501
HCWP0002
HCNL0501
ICMU0018
HCBC0535
HCBC0525
HCWF0504
ICMU0036
ICMU0012
ECKG0042
HCNS1001
ECCS0001
ZCCS0002
HCBC0402
DESCRIPTION
COIL W/SPARK PLUG CAP
SPARK PLUG, CHAMPION (8339-1)
OPTIONAL HOTTER PLUG (8332-1)
OPTIONAL COLDER PLUG (8904-1)
KILL SWITCH ASSEMBLY
SCREW, M5 X 16 (2 PER)
5MM WASHER (2 REQ’D)
5MM WASHER SPECIAL (2 REQ’D)
5MM LOCK NUT (2 REQ’D)
STATOR WITH GROMMET
5mm x 35 SOCKET HEAD CAP SCREW (2 REQ’D)
5mm x 25 SOCKET HEAD CAP SCREW
WASHER FOR STATOR (3 PER)
ROTOR – LOW INERTIA
WOODRUFF KEY
PULLEY, WATERPUMP CRANK
NUT 10MM
IGNITION COVER
GASKET – IGNITION COVER
M4X35 SHCS (4 REQ’D)
19
Parts – Engine – Bottom End and
Transmission
Figure 7A
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
NOT SHOWN
23
24
25
26
27
28
PART #
EKCS0002
EKCS0002
ZCCS0005
HCBC0605
HCBC0608
HCBC0606
ECMU0038
ECMU0016
ECMU0118
ECDC0031
ECMU0099
ECMU0100
ECMU0001
ECKG0031
HCBH0612
HCWL0601
ECMU0020L
ECKGBR01
ZCDCOR01
ECMU0072
ECMU0073
ECKGSR03
PCKG0014
HCBH0805
HCWC0000
ECMU0533
ECMU0534
HCWF0316
ECMU0156
DESCRIPTION
ENGINE CASE SET W/B&S 50 2011 JR
ENGINE CASE SET W/B&S 50 2011 JR
GASKET, CRANKCASE CENTER
6X40MM SOCKET HEAD CAP SCREW (6 REQ’D)
6X55MM SOCKET HEAD CAP SCREW (1 REQ’D)
6X45MM SOCKET HEAD CAP SCREW (2 REQ’D)
CRANKSHAFT
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
M6X12 HEX HEAD SCREW - BEARING RETAINER (2 PLACES)
6MM LOCK WASHER
BEARING, TRANSMISSION PRECISION
BEARING, TRANSMISSION OUTPUT SHAFT
O-RING, SPROCKET SPACER
SEAL, OUTPUT SHAFT
SPACER, SPROCKET
SNAP RING, SPROCKET
SPROCKET, 14 T
M8X12 SCREW – COOLANT DRAIN
COPPER GASKET
FITTING, CRANKCASE VENT
VENT HOSE, CRANKCASE, 9”
WASHER – FLAT
SHIM – OUTPUT SHAFT 50’S (MAY NOT BE NEEDED)
20
Parts – Engine Clutch and Kicker
Figure 7B
Engine – Clutch and Kick Starter
REF #
1
2
3
4
5
6
7
8
9
OPTIONAL
10
11
12
KIT
KIT
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
PART #
CAMU0005
CAMU0013
CCMU0029
CAMU0010
HCBS0004
ECMU0018
ECMU0120
ECMU0119
ECMU0040
ECMU0040T
ECMU0132
EAMU0010
ECMU0162
EKMU0005
EKMU0006
ECMU0138
ECMU0166
ECMU0159
ECMU0169
HCNS1202
EAMU0001
ECMU0116
ZCMUB014
HCWS1622
ECDC0036
ECMU0130
ECMU0250
HCBF0625
ECMU0115
ZCMU0030
ECMU0168
ZCMUB014
HCBC0608
ECMU0207
ECMUSP01
DESCRIPTION
CLUTCH COMPLETE
CLUTCH SHOES (SET OF 3) WITH BOLT & WASHERS
CLUTCH ARBOR
SPRINGS, WASHER & BOLT (SET OF 3)
CLUTCH BOLT (3 REQ’D)
CLUTCH NUT, SPECIAL
CLUTCH BASKET WITH NEEDLE BEARING
CLUTCH BEARING
CLUTCH TO HUB SPACER (0.030”, 0.76MM)
CLUTCH TO HUB SPACER (THIN – 0.015”, 0.38MM)
COOLANT FITTING
CFD V2 HUB / PRESSURE PLATE
PRESSURE PLATE WITH FRICTION MAT
COMLETE GEAR CFD UPGRADE KIT
CFD RFRESH KITW/NUT, SPRING, AND FRICTIONS
FRICTION RING (BRASS), CFD
GEAR, CFD ’09 STYLE
SPRING WASHER, CFD, 60MM OD
CENTERING WASHER, CFD V2
NUT, CFD (½-20 LEFT HAND THREAD – BLUE)
KICKSTART GEAR & SHAFT
SPRING, KICKSTART
O-RING KICK SHAFT
SHIM, KICK SHAFT
SNAP RING, KICK SHAFT
KICK LEVER W/BOLT
WASHER – KICK LEVER MOUNTING
6MM X 25 FLANGE HEAD BOLT
CLUTCH COVER
CLUTCH COVER GASKET
OIL FILL PLUG, ALUMINUM
O’RING, OIL FILL PLUG
6MM X 55 SOCKET HEAD CAP SCREW (6 REQ’D)
KICKSTART GEAR SMALL
KICK START DOG SPRING (PAPER CLIP / ‘J’ SPRING)
21
Parts – Engine – Water Pump
Figure 7C
Engine – Ignition and Water Pump
REF #
1
2
3
4
5
7
8
9
10
11
12
13
14
15
16
PART #
EKMU0011
ECKG0142
ECKG0072
ECKG0074
ECKG0073
HCBC1512
ECMU0167
ECKG0175
ECMU0180
HCBS0003
ECKG0170
ECKG0042
HCNS1001
HCBC0408
HCWF0401
DESCRIPTION
WATER PUMP KIT
SHAFT, WATER PUMP
BEARING, WATER PUMP
SEAL, WATER PUMP SHAFT
IMPELLER, WATER PUMP (ALUMINUM)
5X12MM SHCS STAINLESS
BEARING –WATER PUMP BIG
WATER PUMP PULLEY, FAN TYPE - DRIVEN
BELT RETAINER
SHOULDER BOLT 6MM
WATER PUMP BELT
WATER PUMP PULLEY, CRANK
NUT 10MM
M4mm x 8 SOCKET HEAD black oxide
4MM WASHER
22
Parts – Engine – Top End
Figure 7D
Engine – Top End
REF #
1
PART #
ECMU0129
2
3
5
6
7
8
9
10
ZCKG0501
ECMU0060x
ECMU0155
ECMUSR00
ECKG0012
ECMU0077
ZCMUOR07
ECMU0086
ZCMOTE11
HCBC0612
HCNF0601
HCWS1401
ECMU0530
ZCMUOR02
ZCMUV024
ZCMUOR10
ECMU0532
ZCMUV032
ECMU0075
ZAKGTE05
ZAKGOR05
NOT SHOWN
11
12
13
14
15
16
17
18
19
20
NOT SHOWN
NOT SHOWN
DESCRIPTION
CYLINDER (INCLUDES PISTON, RINGS, PIN & CLIPS)
BASE GASKET 0.015” (0.4mm thick) For other Base Gaskets refer to
Base Gasket Selection section of this manual
PISTON KIT (“x” denotes size, AB, A, C, etc…..)
PISTON RINGS (2 PER SET)
SNAP RING FOR PISTON (2 REQ'D)
WRIST PIN
BEARING, WRIST PIN
O-RING, EXHAUST FLANGE
EXHAUST FLANGE
O-RINGS – PIPE TO FLANGE (2 REQ’D)
M6X12, EXHAUST FLANGE SCREW (2 REQ'D)
6MM FLANGE NUT
HARDENED WASHER
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
STUD, CYLINDER 6mm
TOP END GASKET / O-RING KIT
TOP END/O-RING KIT
23
Parts – Exhaust System
Figure 8
Exhaust System
REF #
1
2
3
PART #
XCCJ2009
ZCMOTE11
XCMU0005
4*
MCMUGR02
5*
MCMUGR10
6*
MCMUGR02
7*
HCWF1478
MCMUGR02
HCBF0635
HCHA0003
HCWF1410
XCMU0032
XCMU0026
HCBB0408
XCMU0028
MCMUGR03
TCKG0001
HCBF0625
FCKG0028
HCHA0003
HCCN0000
NOT SHOWN
8*
NOT SHOWN
NOT SHOWN
9
NOT SHOWN
NOT SHOWN
10
11
12
13
14
NOT SHOWN
NOT SHOWN
DESCRIPTION
2009-2011 CX50JR EXHAUST PIPE
HEADER PIPE O-RINGS (2 REQ’D)
EXHAUST SPRING - SHORT
PIPE GROMMET MALE (ONLY AVAILABLE IN MCMUGR02
GROMMET KIT)
PIPE GROMMET FEMALE
PIPE GROMMET SPACER (ONLY AVAILABLE IN MCMUGR02
GROMMET KIT)
SILENCER GROMMET WASHER (2 REQ’D)
PIPE MOUNT GROMMET KIT
M6X35 FLANGE HEAD BOLT
6MM CLIP NUT – FOR FRONT PIPE MOUNT
FLAT WASHER FOR PIPE MOUNT
SILENCER
SILENCER PACKING KIT
M4 X 8 SILENCER SCREW
PIPE / SILENCER SEAL
MOUNTING GROMMET (4 REQ’D TOTAL, 2 PER BOLT)
SPACER (2 REQ’D)
M6X25 FLANGE HEAD BOLT (2 REQ’D)
BRACKET – RIGHT SIDE RADIATOR SHROUD
6MM CLIP NUT FOR PIPE MOUNTING
5MM CLIP NUT (ON SHROUD BRACKET)
*Parts are included in MCMUGR02 grommet kit.
24
Parts – Forks & Triple Clamps
Figure 9
Front Forks and Triple Clamp
REF #
********
PART #
KACM2007
1
KCMZ0029
NOT SHOWN
KCMZ0131
NOT SHOWN
KACM005R
2
KCMZ0006
NOT SHOWN
KCMZ0010
NOT SHOWN
KACM0007L
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
NOT SHOWN
18
KCMZ0026
KCMZ0027
HCCC0001
HCBC0502
HCNL0501
HCBF0616
KCMZ0025
HCBC0625
KCMZ0005
HCBC0806
KCMZ0003
KCMZ0002
KCMZ0001
HCNJ0102
FCMU0004
FCMU0011
FCMU1103
DESCRIPTION
FORK ASSEMBLY WITH TRIPLE CLAMPS
OUTER FORK LEG – RIGHT (NON BRAKE) SIDE
(NOT AVAILABLE)
OUTER FORK LEG ASSY – RT W/ SEAL & SWIPER
(NOT AVAILABLE)
FORK LEG COMPLETE – RIGHT SIDE
(NOT AVAILABLE)
OUTER FORK LEG – LEFT (BRAKE) SIDE for Disc
OUTER FORK LEG ASSY – LEFT WITH SEAL & SWIPER for Disc
(NOT AVAILABLE)
FORK LEG COMPLETE – LEFT SIDE for Disc
(NOT AVAILABLE)
INNER FORK LEG – RIGHT (COMPRESSION) SIDE
INNER FORK LEG – LEFT (REBOUND) SIDE
CLAMP – BRAKE CABLE
M5X16 SOCKET HEAD CAP SCREW
5MM LOCK NUT
FENDER BOLT, M6X16 FLANGE HEAD (4 REQ’D)
TRIPLE CLAMP – LOWER WITH STEM
M6X25 SOCKET HEAD CAP SCREW (4 REQ’D)
TRIPLE CLAMP – UPPER (NO BAR MOUNTS)
M8X30 SOCKET HEAD CAP SCREW (2 REQ’D)
BAR MOUNT – LOWER (2 REQ’D)
BAR MOUNT – UPPER (2 REQ’D)
M8X50 SOCKET HEAD CAP SCREW
STEERING HEAD JAM NUT (2 REQ’D)
STEERING HEAD BEARING (2 REQ’D)
RACES ONLY FOR STEERING HEAD BEARINGS
DUST COVER (2 REQ’D)
25
Parts – Forks – Leg Assembly
Figure 10
REF #
4
7
8
9
11
12
13
14
15
16
17
18
18A
19
20
21
22
23
26
27
28
29
31
32
PART #
KCMZ0004
KCMZ0007
KCMZ0008
KCMZ0009
KCMZ0111
KCMZ0012
KCMZ0013
KCMZ0014
KCMZ0015
KCMZ0016
KCMZ0017
KCMZ0018
KCMZ0018A
KCMZ0019
KCMZ0006
KCMZ0010
HCWC0000
HCBC0806
KCMZ0026
KCMZ0027
KCMZ0028
KCMZ0029
NOT IN STOCK
HCBC0609
DESCRIPTION
FORK PLUG – BLACK
SNAP RING FOR FORK CAP
INNER FORK CAP - WHITE
O-RING UNDER FORK CAP
PRELOAD SLEEVE
FORK SPRING
SWIPER
SNAP RING
FORK SEAL
WASHER
SEALING RING FOR REBOUND PISTON
PISTON ROD - REBOUND
PISTON ROD - COMPRESSION
REBOUND SPRING
FORK LEG OUTER LEFT
FORK LEG – 5 PIECE UNIT – LEFT
WASHER
8 X 30 CS
FORK TUBE – INNER RIGHT
FORK TUBE – INNER LEFT
TOP OUT BUMPER
FORK LEG – OUTER RIGHT
FORK LEG – 5 PIECE UNIT – RIGHT
6 X 20 CS
26
Parts – Frame – Mounting Hardware I
Figure 11
Frame – Engine, Tank, and Pipe Mounts, Brake Snake
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
30
PART #
WCMU0016
HCNL1201
HCBH0880
HCNL0801
MCMUGR06
MCMUGR10
MCMUSP02
HCWF1478
HCBF0635
HCHA0003
BCMU0008
BCMU0009
TCHA0004
HCNL0601
TCHA0006
HCBF0685
HCBB0635
HCBF0620
HCNF0602
HCBF0625
MCMUGR03
TCKG0001
HCWF1478
HCBF0616
FCMU0057
TCMU0010
TCMU0107
HCBH0840
HCNL0802 &
HCWF0803
BCDC0009
HCBH0620
HCNS0601
MCMUGR02
DESCRIPTION
SWINGARM BOLT
SWINGARM LOCK NUT (M12)
M8X80 SOCKET HEAD CAP SCREW
8MM LOCKNUT
PIPE GROMMET MALE
PIPE GROMMET FEMALE
PIPE GROMMET SPACER
PIPE GROMMET WASHER
M6X35 FLANGE HEAD BOLT
6MM CLIPNUT
CABLE – BRAKE SNAKE (NOT SHOWN)
CRIMP – BRAKE SNAKE (2 REQ’D) (NOT SHOWN)
BUSHING – REAR TANK MOUNTING
6MM LOCKNUT
BUSHING – FRONT TANK MOUNT (2 REQ’D)
M6X85 SHCS
M6X35 BUTTON HEAD CAP SCREW
M6X20 FLANGE HEAD BOLT
6MM NYLOC FLANGE NUT
M6X25 FLANGE HEAD BOLT
GROMMET – SILENCER (2 REQ’D)
SPACER FOR EXHAUST GROMMETS
WASHER – EXHAUST GROMMET
M6X16 FLANGE HEAD BOLT
CHAIN ROLLER
WIDE FOOTPEGS (PAIR) KING STYLE
FOOTPEG SPRINGS (PAIR)(NOT SHOWN)
M8X40MM FOOTPEG BOLT
8MM LOCKNUT & FLAT WASHER (NOT SHOWN)
BRAKE PEDAL PIVOT BOLT
6X20 HEX HEAD
6MM NUT
GROMMET KIT PIPE & SPACER
27
Parts – Frame – Mounting Hardware II
Figure 12
Frame – Seat, Fender, Right Side Panel, Brake Pedal, Silencer & Shock Mounts
REF #
1
2
3
4
5
6
7
8
9
10
11
12
13
PART #
FACJ2011
HCBF1040
ECHA0003
HCBC0608
HCNL0601
MCKGGR00
ECHA0109
HCBC0665
HCBF0616
HCHA0003
HCBH0502
HCWP0002
HCNL0501
HCWF0501
DESCRIPTION
FRAME 2011 CX50 JR
M10X40 FLANGE HEAD BOLT
MOUNTING BRACKET – RADIATOR BOTTOM
M6X55 SOCKET HEAD CAP SCREW
6MM LOCK NUT
GROMMET – RADIATOR MOUNT (2 REQ’D ON BOTTOM, 1 ON TOP BRACKET)
MOUNTING BRACKET – RADIATOR TOP
M6X65 SOCKET HEAD CAP SCREW
M6X16 FLANGE HEAD BOLT
6MM CLIPNUT
5X16 HEX HEAD(2 REQUIRED)
WASHER POP RIVET(2 REQUIRED)
5MM LOCKNUT (2 REQUIRED)
5MM FLAT WASHER (2REQUIRED)
28
Parts – Front Brakes
Figure 14
Front Brakes
REF #
1
2
3
4
5
6
7
8
9
10
11
12
13
PART #
BAKG0003
BCKG0030
BCKG0023
BCKG0024
BCKG0029
BKKG0001
BCMU0503
HCBC0501
HCBF0650
HCBF0630
BCCM0001
BCKG0031
ACCESSORY
ACCESSORY
BCKG0028
BCKG0027
ACCESSORY
BCKG0025
ACCESSORY
ACCESSORY
BCKG0026
BCKG0017
BCKG0018
BCKG0019
ZCMUOR09
BCMU0014
BCKG0033
ACCESSORY
ACCESSORY
ACCESSORY
ACCESSORY
ACCESSORY
DESCRIPTION
FRONT BRAKE ASSEMBLY
HOSE – BRAKE FRONT
ALLOY BRAKE LEVER
BRAKE PERCH & MASTER CYLINDER ASSY W/ LEVER
CALIPER – FRONT
BRAKE PADS, WITH “E” CLIP
BRAKE ROTOR
M5X12 SOCKET HEAD CAP SCREW (6 REQ’D)
M6 X 50 SOCKET HEAD CAP SCREW
M6 X 30 SOCKET HEAD CAP SCREW
SPACER – CALIPER MOUNTING (2 REQ’D)
BLEED KIT (MULTIPLE SYRINGES, FITTINGS & HOSE)
BRAKE FLUID (DOT 4)
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
2MM ID O-RING
29
Parts – Front Wheel
Figure 15
Front Wheel
REF #
1
2
PART #
WACJ0001
WCMU1050B
WCMU1050D
WCMU1050V
WCMUTU10
GCC60015
HCWF1202
WCCJ0002
WCMU0120
WCCJ0004
BCMU0503
DESCRIPTION
WHEEL WITH BEARINGS (NO TIRE & TUBE) ’08 SPOKE STYLE
FRONT TIRE 10X2.50” BRIDGESTONE
FRONT TIRE 10X2.50” DUNLOP
FRONT TIRE 10X2.50” VEE RUBER
TUBE 10”
FRONT AXLE
WASHER – AXLE
WHEEL SPACER LEFT (SHORT)
BEARING – WHEEL (2 REQ’D)
SPACER – WHEEL FRONT
BRAKE ROTOR – FRONT
NOT
SHOWN
HCBC0501
5X12MM SHCS (6 REQ’D)
10
11
HCNL1201
WCCJ0003
LOCK NUT – AXLE
WHEEL SPACER RIGHT (LONG)
3
4
5
6
7
8
9
30
Parts – Plastic & Seat
Figure 16
Plastic and Seat
REF #
NOT SHOWN
1
NOT SHOWN
2
NOT SHOWN
3
Not shown
4
5
6
NOT SHOWN
NOT SHOWN
NOT SHOWN
NOT SHOWN
NOT SHOWN
NOT SHOWN
NOT SHOWN
NOT SHOWN
NOT SHOWN
7
Not Shown
Not Shown
8
NOT SHOWN
NOT SHOWN
9
NOT SHOWN
NOT SHOWN
NOT SHOWN
10
NOT SHOWN
NOT SHOWN
NOT SHOWN
11
NOT SHOWN
PART #
TCCJ2011
TCHA0107
HCBF0616
TCMU0005
HCBF0625
TCHA0008
TCMU0032
TCHA0009
MCMUBC01
TCHA0001
TCHA0002
TCHA0003
HCFH0620
TCHA0005
TCHA0006
HCBC0685
HCNL0601
HCBC0645
TCHA0004
TCMU0151
FCMU0026
MCMUCL04
TCCM0007
HCBB0640
MCMU0013
TCHA0011
HCBF0616
HCBF0620
HCNF0602
TCHA0010
HCBF0616
HCBF0620
HCNF0602
TCHA0112
HCBF0616
DESCRIPTION
GRAPHIC KIT 2011
FRONT FENDER
FENDER BOLT, M6X16 FLANGE HEAD (4 REQ’D)
NUMBER PLATE – FRONT
M6X25 FLANGE HEAD BOLT – FRONT NUMBER PLATE MOUNT
RADIATOR SHROUD – RIGHT
RADIATOR PAD
RADIATOR SHROUD – LEFT
BUNGEE CORD – SHROUD HOLDING
FUEL TANK – NOT COMPLETE
CAP – FUEL TANK
HOSE – FUEL CAP
M6X20 PHILIPS HEAD SCREW – SEAT & SHROUD HOLD
SPACER – SEAT & SHROUD HOLD
SPACER – FRONT TANK MOUNT (2 REQ’D)
M6X85 SHCS – FRONT TANK MOUNT
6MM LOCK NUT – FRONT TANK MOUNT BOLT
M6X45 SOCKET HEAD CAP SCREW
BUSHING – REAR TANK MOUNTING
FUEL PETCOCK
FUEL LINE, 5”
HOSE CLAMPS – FUEL LINE
SEAT
M6X40 SHCS – SEAT HOLDING
STRAP HANDLE
NUMBER PLATE – LEFT REAR
M6X16 FLANGE HEAD BOLT – FRONT SECURE
M6X20 FLANGE HEAD BOLT – FENDER & REAR SECURE
6MM NYLOC FLANGE NUT
NUMBER PLATE – RIGHT REAR
M6X16 FLANGE HEAD BOLT – FRONT SECURE
M6X20 FLANGE HEAD BOLT – FENDER & REAR SECURE
6MM NYLOC FLANGE NUT
FENDER – REAR
M6X16 FLANGE HEAD BOLT – FENDER & AIRBOX SECURE
31
Parts – Rear Brake
Figure 17
Rear Brake System
REF #
1
2
3
4
5
6
7
8
9
10A
10B
11
12
13
14
15
16
17
18
19
ACCESSORY
ACCESSORY
ACCESSORY
ACCESSORY
ACCESSORY
ACCESSORY
ACCESSORY
ACCESSORY
ACCESSORY
PART #
BAKG0002
BCMU0099
BCDC0009
HCBH0620
HCNS0601
BCMUSP02
BCMU0501
BCDC0004
HCBF0620
HCPP0832
HCCC0000
HCCC0006
BCKG0010
HCBF0635
HCBF0620
BCKG0013
BCKG0103
BCKG0006
BCMU0502
HCBC0601
BCKG0012
BKKG0001
BCKG0031
BCKG0014
BCKG0015
BCKG0016
BCKG0017
BCKG0018
BCKG0019
ZCMUOR09
DESCRIPTION
BRAKE COMPLETE
BRAKE PEDAL
BRAKE PIVOT BOLT
M6X20 HEX HEAD BOLT
6 MM NUT
BRAKE RETURN SPRING
SEAL – BRAKE PEDAL (2 REQ’D)
PUSH ROD, REAR BRAKE
M6X20 FLANGE HEAD BOLT (2 REQ’D)
BRAKE HOSE CLAMP FASTENER (2 REQ’D)
BRAKE HOSE CLAMP (2 REQ’D) for hose with clear cover
BRAKE HOSE CLAMP (2 REQ’D) for hose with black cover
REPLACEMENT BRAKE HOSE
M6X35 FLANGE HEAD BOLT
M6X20 FLANGE HEAD BOLT
CALIPER – REAR BRAKE
BRAKE CARRIER WITH PAD
WHEEL SPACER - FLOATING CARRIER
BRAKE ROTOR
M6X16 SOCKET HEAD CAP SCREWS (5 REQ’D)
BRAKE – MASTER CYLINDER - REAR
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
32
Parts – Rear Wheel
Figure 18
REF #
1
2
3
4
5
6
7
9
10
11
12
13
14
15
NOT SHOWN
16
17
18
19
20
PART #
WAKG2007R
WCMU1075D
WCMUTU10
BCMU0502
HCBC1616
PCMU01XX
WCMU0020
HCBH0702
PCMU0100
PCMU0001
WCMU0016
HCPA0002
BCKG0006
BCKG0103
BCKG0104
WCMU0120
WCMU0034
WCMU0101
HCWF1202
HCNL1201
Rear Wheel
DESCRIPTION
REAR WHEEL W/BEARINGS
TIRE – REAR 10X2.75” DUNLOP
TUBE, 10"
BRAKE ROTOR
M6X16 SOCKET HEAD CAP SCREWS (5 REQ’D)
REAR SPROCKET (NO DAMPERS), XX DENOTES TEETH
WHEEL BEARING BRAKE SIDE
M7X30 HEX HEAD BOLT
CHAIN 420 X 100
MASTER LINK 420
REAR AXLE
AXLE HEAD FIXING PLATE
WHEEL SPACER - FLOATING CARRIER
BRAKE CARRIER
BRAKE CARRIER PAD
WHEEL BEARING SPROCKET SIDE
WHEEL BEARING SPACER
WHEEL SPACER
AXLE WASHER
AXLE NUT 12MM
33
Parts – Shock
Figure 19
REAR SHOCK
REF#
1
2
3
4
5
6
PART #
SACM2007
SCMUOH05
SCMUOH04
SCMUOH06
HCBF1040
SCKGOH01
SCKGOH04
SCKGOH05
DESCRIPTION
SHOCK ABSORBER
SPRING – STANDARD (285 lb/in)
SPRING – LIGHT (275 lb/in)
SPRING – HEAVY (295 lb/in)
M10X40 FLANGE HEAD BOLT
SPRING PLATFORM (BOTTOM)
SPRING PLATFORM (UPPER THREADED)
LOCKNUT
34
Parts – Swingarm Assembly
Figure 20
Swingarm
REF #
1
2
3
4
5
6
7
8
9
11
12
13
14
15
16
17
18
19
20
21
22
23
24
PART #
GACJ2011
GCMU0001
GCCJ0001
GCMU0017
HCFH0516
HCWF0501
HCNL0501
HCBF0620
PAKG0001
PCKG0004
HCBFT640
HCNL0601
FAMU0005
FCMU0203
FCMU0202
HCWF0801
HCBH0810
WCMU0016
HCNL1201
HCBF1040
WCMU0016
HCPA0002
HCNS1201
DESCRIPTION
SWINGARM 2011
SWINGARM BUSHING (SINGLE PIECE)
SPACER - PIVOT TUBE
CHAIN GUARD
M5X16 FLAT HEAD SCREW
5MM FLAT WASHER
5MM LOCK NUT
M6X20 FLANGE HEAD BOLT (2 REQ’D)
CHAIN GUIDE – ASSEMBLY COMPLETE
CHAIN GUIDE - BOTTOM SLIDER
M6 X 40 FLAT HEAD BOLT
6MM LOCKNUT
WHEEL PULL ASSEMBLY
WHEEL PULL
WHEEL PULL ENDCAP
8MM FLAT WASHER
M8X65 HEX HEAD BOLT (FULL THREAD)
SWINGARM PIVOT BOLT 195MM
12MM LOCK NUT
M10X40 FLANGE HEAD BOLT
AXLE BOLT 195MM
AXLE HEAD FIXING PLATE
12MM LOCKNUT
35
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
Engine NEEDS Rebuilt
Measured Value * 0.8
110 psi * 0.8 = 88 psi
Procedure for Compression Testing
1. Shut off the fuel petcock.
2. Install the compression gauge into the spark plug hole.
36
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 21 for location) along with
the table below to reorder the correct thickness gasket.
Figure 21
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
NOTE
Tolerances will affect the actual gasket thicknesses.
37
Cobra #
Part #
ZCMU0703
ZCKG0501
ZCMU0705
ZCMU0706
ZCMU0707
ZCMU0708
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 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
38
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 (Call local dealer for details).
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.
8.
9.
Remove the master link from the chain.
Remove front engine mount bolt (13 mm socket, 6 mm hex key).
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 magneto 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).
39
6. Remove the left hand thread blue nut holding the CFD to the transmission
input shaft (19 mm socket).
7. Remove the special nut / starter gear that holds on the clutch (special tool
available, contact your local dealer).
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.
2.
3.
Remove the cylinder head nuts (10mm).
Remove the cylinder head outer.
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.
6.
Remove the piston clip with a scribe.
Remove the piston pin with a piston pin remover.
40
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 0.008” (0.2 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.
7.
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)
Install the water pump assembly wire ring retainer
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).
CAUTION:
Insert a 7.05mm (0.278”) shim between the crank throws before pressing on the
crank.
8.
Insert the case screws with the proper lengths at locations shown.
41
Figure 28
9. Torque to 12 Nm (105 in-lb) in the pattern shown in figure 28.
10. Trim away any excess gasket material if necessary.
NOTE: Check engine mount holes for excess material that may cause problems
in engine installation.
11. 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.
12. Install the piston rings.
CAUTION:
Ring end gap should be no less than 0.25 mm (0.010”) and no more than
0.64mm (0.025”)
13. Install the base gasket.
CAUTION:
See base gasket selection at the beginning of service section.
14. 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.
15. Install cylinder head insert.
42
NOTE: A light application of silicone grease can help
hold the O-rings into position during assembly.
16. Install O-RINGs as shown in figure 29.
17. Install the cylinder head.
18. Install the washers (with flat side down) and nuts.
Torque to 105 in-lb (12 Nm)
19. Install reed and inlet manifold with new gasket (105
in-lb, 12 Nm).
20. Leak check the engine at 20 psi to ensure proper
seal.
21. Install stator reinstalling the grommet and wires
22. Install the rotor per Rotor Installation section, under
the S3: Ignition portion of this manual.
23. 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 a bench.
Figure 29
24.
25.
26.
27.
28.
Install the CFD.
Install the clutch per Clutch Installation section in this manual.
Install the coolant drain plug with copper washer (11 ft-lb, 15 Nm).
Make sure that the exhaust spacer is on the cylinder (53 in-lb, 6 Nm).
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 for 2011, Cobra has again 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.
43
Factors that affect what the clutch spring stack should be include
1) Amount of wear on shoes (this is difficult to measure and can only be
approximated by the step in the shoe where it rides outside the basket – new
shoes will not have one, old shoes will have a large one).
2) 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.
44
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.
Cobra clutch puller assembly:
Figure 30
Figure 31 Clutch puller installation
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) & spanner wrench (ECMU0082).
• 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)
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.
4. If necessary apply heat to the center clutch hub.
45
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.
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
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
46
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 #
HKCSM015
HKCSM012
HKCSM008
HKCSM006
HKCSM005
HKCSM004
HKCSM003
HKCSM001
HKAM0022
Thickness mm (inch)
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)
CLUTCH SHIM KIT
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:
• 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.
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’.
47
REF #
1
2
3
4
5
6
PART NO. DESCRIPTION
ECMU0118
ECMU0040
ECMU0040T
ECMU0119
ECMU0120
CAMU0005
ECMU0018
CCMU0029
Crank seal
Clutch to hub spacer (standard 0.030” 0.76mm)
Clutch to hub spacer (thin, 0.015” 0.38mm)
Needle bearing
Clutch basket with bearing
Clutch Complete w/ Arbor
Clutch nut
Clutch arbor
Figure 33, Clutch Assembly Drawing
Clutch Assembly:
1. After cleaning or replacing the spring washers, reassemble the stack up of
washers.
CAUTION:
It is also important that all three shoes are stacked the same. (See figure 32)
2. Clean the threads of the stack bolt and the clutch with brake cleaner removing
all old thread locking material.
3. Apply high strength thread lock material to the stack bolt and tighten to 12 ftlb (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 center hole of the clutch and on the tapered section of the
crankshaft.
48
5. Apply a small amount of wicking / bearing retainer (green) thread lock agent
to the center tapered section of the crankshaft and taper of clutch arbor.
CAUTION:
Lean the bike / engine such that any excess thread lock agent goes away from
the bushing in the clutch drum.
6. Put the clutch back in.
7. Apply high strength thread locking agent to the threads and install the nut and
torque to 40 ft-lb (54Nm) with the special socket (see figure 33).
CAUTION:
Use high strength (red) thread locker on the threads of the clutch nut. If you are
using an impact socket, just zap it lightly with an air wrench to tighten it because
there are only about 4 threads inside the nut and they can be easily stripped. If
you are tightening it by hand, you can hold the crank from turning with the clutch
removal spanner ECMU0082.
Install the clutch cover tightening the bolts from inside out. (8 or 10 mm socket,
5.8 ft-lb, 7.8 Nm).
INSPECTION NOTE:
• There must be in / out play in installed clutch, 0.4mm to 1.0 mm
(0.015” to 0.040”).
• Excess in/out will cause early crank seal failure.
• A blue clutch drum is worn out from excessive slippage or improper
lubrication.
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.
Fill with oil (235 ml (8.0 oz) Cobra 3 Shoe Clutch Milk (Part # MCMUGF32).
Ignition
Stator care
Stator failure will 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.
49
4. Clutch slippage. See “CLUTCH” section for causes of slippage.
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 0.035” before Top Dead Center
(that means 0.035” 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
• 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.
6. Set the dial indicator to zero
7. Turn the crankshaft clockwise until the dial indicator reaches 0.035” (0.9mm)
from top dead center.
8. At this position the line on the rotator 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.
50
0.035”
before
TDC
Figure 26, Lining up the line on the rotor
with the line on the stator.
Figure 27, Using a dial indicator to measure
piston height for setting ignition timing.
ROTOR INSTALLATION:
1. Torque the nut on the rotor to 40 ft-lb (54 Nm) with high strength (red) 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.
51
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 41 - 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.
52
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.
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.
53
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.
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.
54
•
•
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.
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.
55
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.
CAUTION:
1. 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 34.
Figure 34 Proper carburetor top installation and
location of rectangular slide indexing pin and
vent elbows.
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. (See figure 35)
Figure 35
The presence of light indicates that the reeds should be replaced, or possibly
turned over.
56
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.
Signs of your silencer needing to be
Wheels & Tires
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 36
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).
57
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
• Shoe thickness (difficult to measure accurately - can only be approximated by
the size of the step where it sticks out of the basket)
• 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:
i) Clutch spring stack is to short
(1) Wrong configuration
(2) Sacked out (over stressed) washers
(3) Too thin a flat shim in the stack
ii) Spring rate too low (wrong configuration with proper stack height)
iii) 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:
i) Clutch spring stack to tall
(1) Wrong configuration
(2) Too thick a flat shim in the stack
58
ii)
iii)
iv)
v)
Spring rate too high (wrong configuration with proper stack height)
Clutch arbor shoulder bolt is too short
Clutch shoe material has worn too thin
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.
Also refer to the Clutch Service section of this manual for more information on
proper clutch care.
Gearing
For a bike with a centrifugal clutch, it’s better to be geared too low than too
high.
What happens with improper gearing?
•
Poor performance
•
Not enough top end speed
•
No snap
•
Over heat clutch
•
Premature failure of engine seals, bearings, & electronics
•
High clutch wear
59
Condition
Gear Taller
Gear Lower
Mud
Sand
Hills
Hard Pack
Throttle Blipper (novice)*
*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
stock
15
13
14
15
13
14
13
14
13
14
13
13
13
Rear
Sprocket
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
60
Gear Ratio
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
Ratio Write © Cobra R&D
2004
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 (optional 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. Fork height
1.3.1. Rise in clamps for quicker turning.
1.3.2. Lower in clamps for improved straight line stability.
2. Rear shock
2.1. Shock spring (optional spring)
2.1.1. Stiffer spring – stiffer throughout the travel.
2.1.2. Less stiff spring – less stiff throughout the travel.
2.2. Compression damping (optional valve)
2.2.1. Harder (more damping, slower) – adds resistance to the
suspension motion when the suspension is compressing.
2.2.2. Softer (less damping, quicker) – reduces resistance to the
suspension motion when the suspension is compressing.
2.3. Rebound damping (optional valve)
2.3.1. Harder (more damping, slower) – adds resistance to the
suspension motion when the suspension is returning to full length.
2.3.2. Softer (less damping, quicker) - reduces resistance to the
suspension motion when the suspension is returning to full length
Front Forks Bottoming Too Frequently
Fork oil level
If the front forks bottom harshly more than a couple of times per lap and the fork
springs are proper for the weight of rider (as detailed above), try raising the fork
oil level in increments of 10mm. Raising the fork oil level, reduces the air volume,
and increases the stiffness of the forks late in the travel, thus adding a
progressive’ feel.
Front forks feel too stiff over small bumps.
Fork oil weight
If the forks feel too stiff over small bumps try decreasing the weight (increasing
the viscosity) of the fork oil.
61
Rear suspension troubleshooting.
Damping
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
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
Proactive Suspension Adjustments
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.
Rear shock
The rear shock on your Cobra is adjustable to your riders weight and riding style
by changing the spring rate (stiffness) of the spring and / or by changing the
damping valves.
Due to the complexities of the shock absorber internals, Cobra recommends that
you either send the shock back to us for damping valve changes or send the
shock to a competent suspension specialist such as PR2.
Cobra offers stiffer and softer shock springs depending on the weight of your
rider. See the Parts Shock section or the Optional component section at the
beginning of the manual for these other components.
Front Forks
Cobra offers stiffer and softer fork springs depending on the weight of your rider.
See the Parts Shock section or the Optional component section at the beginning
of the manual for these other components.
62
The front forks are designed with the damping components in separate fork legs.
The compression damping duties are performed in the right fork leg and the
rebound damping duties are performed in the left fork leg. This allows easy
adjustment of the damping characteristics by appropriately changing the viscosity
of the fork oil in the fork leg controlling the damping characteristic that needs
changed.
Example: if stiffer compression damping is required, switch from 20 (standard)
weight fork oil to 25 or 30 weight oil in the right leg. If softer rebound damping is
desired, switch from 20 (standard) to 15 or 10 weight fork oil in the left leg.
NOTE:
Fork oil level affects bottoming harshness, and oil viscosity affects valving speed.
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.
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)
63
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)
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
64
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.
65
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
66
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
67
Index
Air Filter Maintenance .....................11
Forks
Airbox
Parts ...............................................25
Parts ...............................................15
Frame Parts ......................................27
Bars and Controls ............................16
Frictional Drive ..................................13
Base Gasket Selection....................37
Front Brake
Break-In ............................................... 6
Parts ...............................................29
Carburetor
Front Forks
Parts ...............................................17
Service ...........................................62
Service ...........................................54
Front Forks: .......................................62
Specifications.................................. 4
Front Wheel Parts ............................30
Tuning ............................................63
Fuel System
CFD Cobra Frictional Drive ............13
Service ...........................................54
Chain
Gearing ..............................................59
Adjustment ....................................11
Hardware and Fasteners
Chassis
Frame.............................................27
Specification.................................... 4
Plastic.............................................31
Clutch
Ignition
Parts ...............................................21
Parts ...............................................22
Clutch Lubricant
Timing ............................................50
Replacing .......................................10
Jetting
Compression test .............................36
How To...........................................54
Cooling System ................................51
Stock ................................................ 4
Electrical
Troubleshooting ............................63
Parts ...............................................19
Lubrication
Engine
Recommended ............................... 4
Specifications.................................. 4
Maintenance
Exhaust..............................................57
Schedule .......................................... 8
Parts ...............................................24
Tips................................................... 8
Fork Oil
Oil
Replacement .................................12
Recommended ............................... 4
68
Optional Components........................ 5
Rear Wheel
Parts
Parts ...............................................33
Airbox and Filter ...........................15
Pullers ............................................57
Bars and Controls ........................16
Reeds.................................................56
Bottom End & Transmission.......20
Shock .................................................62
Carburetor .....................................17
Parts ...............................................34
Clutch & Kick Starter ...................21
Service ...........................................65
Coolant System ............................18
Slip Clutch.........................................13
Electrical ........................................19
Spark Plug
Engine ............................................20
Recommended ............................... 4
Exhaust..........................................24
Specifications...................................... 4
Forks ..............................................25
torque values .................................. 5
Frame.............................................27
Starting ................................................. 7
Front Brake ...................................29
Suspension .......................................65
Front Wheel...................................30
Swingarm Parts ................................35
Ignition & Water Pump ................22
Top End
Inlet.................................................15
Parts ...............................................23
Plastic & Seat ...............................31
Service ...........................................36
Rear Brake ....................................32
Torque Values .................................... 5
Rear shock ....................................62
Transmission
Rear Wheel...................................33
Specifications.................................. 4
Shock .............................................34
Transmission Lubricant
Swingarm.......................................35
Replacing .......................................10
Top End .........................................23
Troubleshooting ................................66
Triple Clamps................................25
Jetting .............................................63
Parts List
VIN reading ......................................... 8
Front Forks ....................................62
WARNING ........................................... 1
Plastic & Seat Parts .........................31
Water Pump
Pullers ................................................57
Parts ...............................................22
Rear Brake
Wheels
Parts ...............................................32
Service ...........................................57
69