Instruction Manual for KEIHIN PE24 Carburetor Kit
(Paper-type filter) Item No.
：０３―０５―３２６
：０３―０５―３２６１ (Sponge-type filter)
・We are flattered that you have purchased one of TAKEGAWA’s products. Please strictly follow the following instructions in installing and using the
products.
your dealer.
Fits
CRF50F
XR50R
Frame Nos
：AE03-1400001 ∼
： AE03-10000 1∼
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Please do read the following before installation.
◎ We do not take any responsibility for any accident or damage whatsoever arising from the use of the products not in conformity with the instructions
in the manual.
◎ We shall be held free from any responsibility or compensation whatsoever for any glitch in the parts other than ours if the glitch takes place after the
installation and use of thse products.
◎ The installation of the products entails machining of a stopper on the throttle pipe. And please note that with the machining, an accelerator limiter will
get unavailable.
◎ Do the installation work correctly referring to Honda’s genuine service manual for the above-mentioned applicable models.
◎This kit is designed for exclusive use in the above-mentioned applicable models and frame numbers only. Please take note that this kit cannot be
mounted on other types of motorcycles.
◎ If you make modifications to the products, we shall be held free from any guarantee of the products.
◎ You are kindly requested not to contact us about the combination of our products with other manufacturers'.
◎ Setting of a carburetor needs to be adjusted depending on the natural phenomena like the weather, temperatures, and motorcycles and carburetors
themselves. Arrange the setting to match the engine and other conditions. For your information, the carburetor is shipped out in a state described on
page 2.
Caution
The following show the envisioned possibility of injuries to human bodies or property damages as a result of disregarding the following cautions.
・Work only when the engine and the muffler are cool. (Otherwise, you will burn yourself.)
・Prepare right tools for the work, (Otherwise, the installation with improper tools could cause breakage of parts or injuries to yourself.)
・Always use a torque wrench to screw bolts and nuts tight and securely to the specified torque.
(Improper torque could cause these parts to get damaged or fall off, resulting in accidents.)
・As some products and frames have sharp edges or protruding portions, please work with your hands protected.
(Otherwise, you will suffer injuries.)
・Before riding, always check every section for slack in parts like screws. If you find slack ones, screw them securely up to the specified
torque. (Or improper torque may cause parts to come off.)
・Always use new gaskets and packings. And check those parts to be reused for wear and damage. If you find wear or damage, replace them
with new ones.
Warning
The following show the envisioned possibility of human death or serious injuries to human bodies as a result of disregarding the following cautions.
・Always start the engine in a well-ventilated place, and do not turn the engine on in an airtight place.
(Otherwise, you will suffer from carbon monoxide poisoning.)
・When you notice something abnormal with your motorcycle while riding down a road, stop riding immediately and park your motorcyle in a safe
place. (Otherwise, the abnormality could lead to accidents.)
・Before doing work, secure the motorcycle on level ground for safety's sake.
(Otherwise, your motorcycle could overturn and injure you while you are working.)
・Check or carry out maintenance of parts correctly according to the procedures in the instruction manual or a service manual.
(Improper checking or maintenance could lead to accidents.)
・If you find damaged parts when checking and performing maintenance, do not use these parts any longer, and replace them with new ones.
(The continued use of these damaged parts could lead to accidents.)
・As gasoline is highly flammable, never place it close to fire. Make sure that nothing flammable is near the gasoline. Since vaporized accumulation
of gasoline is at high risk of explosion, work in a well-ventilated place. (It may cause a fire.)
◎ Please be informed that, mainly because of improvement in performance, design changes, and cost increase, the product specifications and
prices are subject to change without prior notice.
◎ This manual should be retained for future reference.
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∼ Kit Contents ∼
３
No.
１
２
１５
1
2
3
Carburetor assembly
Inlet pipe
Insulator
１６
１３
９
１０
１４
１１
１２
６ ７
４
５
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Factory preset mode of the carburetor
Main jet
Slow jet
Jet needle
Clip position
#108
#48
36S
3rd from the top
4
5
6
7
8
9
14
15
16
Band
Inlet pipe gaslet
Socket cap screw, 6x20
Socket cap screw, 6x15
Throttle cable, 710mm
Fuel tank front spacer, 30mm
Fuel tank rear spacer, 20mm
Flange bolt, 8x55
Flange bolt, 8x40
Collar
Washer
Air filter
Fuel hose, 200mm
TOOL Hex wrench, 6mm
Throttle valve 1SC
Cut-way #3.0
Air screw opening 1-1/2
Part Name
∼ Installation Procedures ∼
※Make sure your bike is secure on level ground for safety’s sake.
２．Carburetor Detachment
◇ Shut off a fuel cock, and open a drain cock on the carburetor to drain
gasoline from the float chamber.
◇ First detach from the carburetor a top cap, hose of a storage tank, bolt on
the air cleaner stay and two bolts on the manifold, and then detach a
manifold, carburetor and air cleaner.
１．Detachment of Exterior Parts
◇ First detach two trim clips, two screws and two bolts, and then detach an
assembly of a seat, shroud and rear fender.
Qty
1
1
1
1
1
2
1
1
1
1
1
1
1
2
1
1
1
Bolt
Top cap
Assembly of seat / shroud / rear fender
Trim clip
Screw
Bolts Hose
◇ Attach an earth cable to the frame with the bolt on the air cleaner stay.
Bolt
◇ Detach a fuel hose from the carburetor, and detach two bolts to demount
a fuel tank.
Bolts
Collar
Washer
Earth cable
Bolt
◇ Unscrew a bolt on the storage tank, and pull out a breather hose from the
crankcase.
Fuel tank
Storage tank
Bolt
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３．Detachment of Throttle Cable
◇ Loosen a hex nut on the throttle cable.
◇ Unfasten two screws, and detach a throttle housing and throttle pipe from
the handle.
◇Attach the throttle valve to the carburetor, aligning the notch with the
throttle stop screw.
※ Snap the throttle a few times to check how much the throttle valve opens
and closes.
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◇ You are requested to dispose of the blow-by gas from the crankcase by
yourself.
(For example: Attach the storage tank so the air filter does not interfere
with the tank, and let the blow-by gas into the air filter with
a breather hose of the kit.)
◇ Machine the stopper on the throttle pipe to remove it.
Stopper
Notch
Throttle stop screw
◇ Attach a throttle cable of the kit to the lower throttle housing.
◇Connect an inner cable to the machined throttle pipe, and fix the throttle
housing to the handle with two screws.
◇ Tighten hex nuts on the throttle cable.
５．Attachment of Carburetor
◇Place a gasket between cylinder head and inlet pipe, and tighten the
gasket with socket cap screws. Fix firmly the insulator into the inlet pipe
with a socket cap screw.
Torque= 10 N・m (1.0 kgf・m)
６．Attachment of Exterior Parts
◇ Put a front tank spacer between the front fuel tank and frame, and attach
a bolt. And put a rear tank spacer between the rear fuel tank and frame,
and attach the collar and kit’s washer, and fasten the bolt.
Bolt 8x55 Bolt 8x40
Insulator
Washer
Screws 6x15
Screws 6x20
Gasket
Carburetor
Band
◇ Place the carburetoe into the insulator, and tighten the band to secure it.
◇Remove the top cap from the carburetor, and detach the spring, needle
clip, retainer and throttle valve.
◇Attach to the throttle cable the top cap, spring, throttle valve, and then the
needle clip retainer.
Collar
Stock collar
Front tank spacer Rear tank spacer
◇Put a prong on the back of the seat into a hook on the frame, and attach an
assembly of seat / shroud / rear fender with two each of trim clips,
screws and bolts.
※ Pulling the shroud, align the mounting hole with a threaded screw hole in
the fuel tank, and fit two screws into the holes.
In case it’s hard to fit the screws, elongate the holes with a rasp and the
like.
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Co.,Ltd.
3-5-16 Nishikiorihigashi Tondabayashi Osaka Japan
TEL : 81-721-25-1357 FAX : 81-721-24-5059 URL : http://www.takegawa.co.jp
How to Set the Carburetor
・When the carburetor does not match the engine and the engine fails, the engine failures are caused by either too dense or too lean air-fuel mixture.
・The engine failure symptoms for the engine are as follows:
When the air-fuel mixture is too dense:
・The explosion sound with a dull thud continues intermittently.
・The engine malfunctions further if you use the choke.
・The engine malfunctions when you warm it up.
・The engine works well if the cleaner is detached.
・The motorcycle belches dense (or, black) exhaust gas.
・The plug smolders, getting blackened.
When the air-fuel mixture is too lean:
・The engine overheats somewhat.
・The engine starts working well If you use the choke,.
・The engine does not accelerate well. (No smooth acceleration)
・Revolutions change, generating weak power.
・The plug burns white.
Whether or not the engine revolution is in proportion to the throttle operation
・When the acceleration is not smooth or even, make the air-fuel mixture dense.
・Make the air-fuel mixture lean when the engine revolution goes up heavily and belches black gas.
The mixture ratio at this throttle position can be adjusted by the location of E-ring in the grooves. The air-fuel mixture becomes dense as the
location of the E-ring moves down from the 1st to the 5th groove.
○Main jet (The throttle position at 3/4 - 4/4)
The air-fuel mixture ratio at this throttle position can be adjusted by changing the number of the main jet. The larger the main jet numbers, the
denser the mixture ratio becomes.
In view of the engine and muffler specifications, select the most appropriate main jet to get the highest revolutions.
○Pilot jet (First of all, please adjust the air screw.)
・In case you have given more than three turns to the air screw to tighten it, use a pilot jet with a small number.
・ If you have tighten the air screw (clockwise) to the full, use a pilot jet with a larger number.
Check whether you have made a right choice of the pilot jet by seeing if the engine starts up revolving smoothly from the idling to running
at slow speed.
・When the engine revolves up unevenly, the pilot jet number is too small. (At idle)
・ When the motorcycle belches black exhaust gas and produces heavy exhaust sound, the pilot jet number is too big. (At idle)
・After replacing the pilot jet, you need to readjust the airscrew.
○ Air screw
The air screw adjusts the air mass flow at the time of engine’s revolving at slow speed. (At idling)
・Give the air screw a right turn → The air-fuel mixture gets dense.
・Give the air screw a left turn → The air-fuel mixture gets lean.
Loosen the tightened air screw back to the 1.5-turn position. And then from this position, give to the airscrew a right or left turn of 1/4 to 1/2
till the engine revolves at the highest speed.
Loosen the idle stop screw till you get the steady idling revolutions. And once again adjust the position of the airscrew to get the highest
revolutions.
●On how the barometric pressure, temperatures and humidity affect the setting:
・At highlands or at high altitudes, the barometric pressure and air density go down and the air gets into the carburetor in less amounts.
This makes the air-fuel mixture dense which was adjusted at low altitudes.
・Under the weather conditions with very low temperatures, the air density increases, which makes the air-fuel mixture lean.
・Under the rainy and humid weather conditions, the air density decreases, which makes the air-fuel mixture dense.
◎ Please be informed that, mainly because of improvement in performance, design changes, and cost increase, the product specifications and
prices are subject to change without prior notice.
◎ This manual should be retained for future reference.
Co.,Ltd.
3-5-16 Nishikiorihigashi Tondabayashi Osaka Japan TEL : 81-721-25-1357 FAX : 81-721-24-5059 URL : http://www.takegawa.co.jp
