Big Bore Carburetor Kit (PC20) Instruction manual
Product number

03-05-0244 (Carburetor kit)
03-02-052 (Manifold set)

Adaptation model

Monkey / Gorilla (Z50J-1300017 ～ )(AB27-1000001 ～ 1899999)
Monkey BAJA

Thank you very much for purchasing our products.
Thank you so you will comply with the following matters at the time of use.Before installation, please check your always kit contents.
If there is a point of notice event, Please contact us the dealer of purchase.
◎ If the description, such as photos or Illustration different with this part.

☆ Please read carefully before use ☆
◎ The use of ignoring the instructions that are written in the instruction manual, if an accident or damage has occurred, we can notassume any responsibility for compensation.
◎ This product installation and use, when a problem occurs to after market goods, guarantee other than this product, also can notassume any in any such matters.
◎ If it was the case or mounting that has been processed like a product, it will not be covered under warranty.
◎ It is not possible to inquire of the combination of other manufacturers.
◎ These products are designed for the exclusive use in the S-Stage kit for Monkey / Gorilla machines only. Please take note that thse
products cannot be mounted on stock engines or other types of vehicles.
◎ The throttle valve of vehicles with frame Nos from 1300017 to 1510400 will not open fully when stock throttle housing is used.
Therefore,it is necessary to replace it with a high throttle sold separately, or process the throttle pipe (refer to P. 3 for detail).
Also, the centrifugal clutch vehicle with the above frame number can not install the included throttle cable.
Please change to our high throttle sold separately.
◎ In case a stock throttle housing is used in your vehicle, it is also necessary to replace the standard throttle cable with ahigh-throttle cable included in the kit.
◎ In order to install a high-throttle, you need to remove the stock throttle housing; therefore you cannot use the front brake lever,turn signals, or a horn switch used in the vehicles with frame Nos from Z50J-1300017 to 1510400. In those vehicles with frame Nos
Z50J-1600008 or above, you can not use the front brake lever either, so you need to prepae a substitute lever (A power lever
06-08-300 is installable).
◎ Please take note that you cannot run the vehicle with this kit in the rain.
◎ For the vehicles (with frame numbers from AB27-1000001 or above) with a crankcase emmition control system, you will additionally needan air filter which is compatible with such a control system (03-01-110 or 03-01-1105).
◎ Carburetor’s setting varies according to parts used, natural phenomena, or others. Please adjust the setting based on size of thejet included in the kit.

CO～ feature ～PY○ It is designed for exclusive and easy use for Monkeys / Gorillas of S-Stage Kit. In order for you to use the stock throttle housing,it includes a cable for highthrottle. Installation can be done without processing any parts (there are some exceptional vehicles)with use of a machined skin funnel, a curling funnel,and an air filter.
CautionWhen the handling of ignoring this display, property damage and human shows the assumption of what injury.

■ When performing the work, etc., be sure during the cold (when the engine and the muffler is cold). (It may cause burns.)■ When performing the work, it should be made to prepare the tools for the job. (Breakage of parts, it may cause injury.)■ Do the work must always specified torque using a torque wrench. (Damage of bolts and nuts, and cause of dropout.)■ The product and the frame, might have edges or protrusions. Please go to protect your hands when you work. (It may cause injury.)■ Be sure to each part inspection before operation, check the loosening of the threaded portion, be sure to securely tighten thespecified torque if there is loose. (It may cause detachment of the parts.)■ Always use a hose clip to connect the hose firmly to the carburetor.
■ Never look into the carburetor’s intake pipe without discretion while engine is runing. Flames could spurt by the spitting-back ofgasoline or backfire.
■ Setting of a carburetor varies according to the natural phenomena like the weather, temperatures and barometic pressure, combinationof parts used and the vehicle itself. Arrange the setting to match the engine.
■ Before riding, always check every section of your vehicle for slack in parts like screws, and oil leak. When you notice somethingabnormal with your motorcycle while riding down a road, stop riding immediately and park your motorcyle in a safe place to check for
abnormalities. Otherwise you may have an accident.
Warning

When the handling of ignoring this display people died, shows the contents of the serious injury possibility isassumed.

■ Those who are technically unskilled or inexperienced are required not to do the work.
(Improper installation could lead to riders falling down or accidents as a result of parts breakage.)■ Always drive the engine in a well-ventilated place, and do not switch the engine on in an airtight place.
(Otherwise, you will suffer from carbon monoxide poisoning. )■ Before doing work, place the motorcycle on level ground to stablize the position of your motorcycle for safety’s sake.
(Otherwise, your motorcycle could fall down and injure you while you are working.)■ 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 the high risk of explosion, work in a well-ventilated place.
◎ Please note. Performance up, the design change, the product and the price in the cost up, etc. are subject to change without notice.
◎ Please be informed that we shall be held harmless against any claim against us whatsoever arising out of use of the products inracing and the like.
◎ Keep this manual stored until this product is discarded.
CONTACT Address : 3-5-16 Nishikiorihigashi Tondabayashi Osaka JAPANTEL: +81-721-25-1357 FAX:+81-721-24-5059 e-mail:english@takegawa.co.jp URL http://www.takegawa.co.jp
Please contact with your name and country name provided. (Only English please)2022.2.703-05-0244,03-02-052

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Product content

①②③⑥

④

Factory Setting of a Carburetor⑤

Main jet#95
Slow jet#35
Jet needle
63001
Clip position
4th.
Throttle valve#20G
Air screw opening 1-1/2 turns⑦

NumberProduct content
Quantity
Item Number
103-03-0077
1 Carburetor ASSY.(PC20)※ 2 Intake manifold
100-00-1484※ 3 Intake manifold gasket
100-01-0159 (2 pcs)
※ 4 Carburetor gasket
100-03-0417※ 5 Socket cap screw, 6x25
400-00-0722 (5 pcs)
6 Throttle cable COMP.(710mm)
109-02-0071※ 7 Hex wrench, 5mm
1CO※ means the parts are a part of a manifold set.
∴ Please order in the repair parts are always repair part number.
If it is not the part number order, you may not be able to order.
Please be forewarned.
It should be noted, In the case of parts that can not be separately
shipment, please order a set part number.

■ Mounting procedure※ Please refer to the Genuine Service Manual for detailed mounting methods and specified torques that are notspecifically described.

First of all,check the contents of the kit.

（Preparation for Installation）○ Remove a side cover and a seat, anddrain the gasoline in the fuel tank.
Then close the fuel cock, and pull out
the fuel hose on the side of a carburetor
and the fuel tank.

○ After checking that the fuel cock is closed,
open carburetor’s drain cock to drain
the gasoline in the float chamber to atray.

PY○ Unfasten the inlet pipe fixing bolt and the
air cleaner mounting bolt, and remove thecarburetor with the air cleaner case andthe inlet pipe attached.
※ Be careful not to let any foreign material
fall into the intake port.

○ Remove the throttle valve from thecarburetor,divide the throttle valve andthe throttle cable,and take the top coverfrom the throttle cable.

○ Unscrew pan screws in the throttle housing,and disconnect the throttle cable.
Then, wipe off the smear, dirt, dust andold grease.
※ Keep the throttle housing and pan screws
for re-use.

Pan screw○ Fix the earth wire to the frame with an
air cleaner mouting bolt.

Earth wire
Top cover

Drain cock2022.2.7○ Keep the removed parts in a bag orsomething else.

03-05-0244,03-02-052

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■ Mounting procedure※ Please refer to the Genuine Service Manual for detailed mounting methods and specified torques that are notspecifically described.

（Installation）○ Temporarily tighten the throttle cablein the kit to the under throttle housing,and connect the inner cable to thethrottle pipe.

○ Put the carburetor gasket between thecarburetor and intake manifold, and tighten
the gasket with 6x25 socket cap screw tothe specified torque.
Note: Be sure that you protect specified
torque.
Socket cap screw

Torque：10N・m（1.0kgf・m）

CO○ Apply grease to the sliding surface on
the throttle, and install the throttle
housing.
Tighten the pan screws.
Note: Be sure that you protect specified
torque.
Pan screw

Torque：8N・m（0.8kgf・m）

Pan screw○ Reinstall the fuel tank, and then theseat.
○ Make adjustments of the direction of thefuel cock and the length of the fueltube, then, insert it into the fuel cockand the carburetor, and fix the tube clip.
Open the fuel cock and check for oil leak.
(Do not leave the cock open for a long time.)

Socket cap screw○ Remove the cramp on the wire harness.
Fix the wire harness, sliding it so that
it will not interfere with the carburetor.
Fix the gasket first and then the intake
manifold to the cylinder head.
Tighten the 6x25 socket cap screws to thespecified torque.
Note: Be sure that you protect specifiedtorque.
Socket cap screw○ Pull the choke lever to start the engine,and check for any intake gas leak.
Gradually push the lever back and warm-up
the engine till it starts running smoothly,and push back the choke lever to the end.
Adjust the throttle stop screw in casethe engine does not run idle after thewarming up or runs idle at high speed.
○ Be sure to do setting according to eachvehicle in a safe place and with care.

Torque：10N・m（1.0kgf・m）○ Remove the top cover of the carburetor,
then the throttle valve spring and thethrottle valve.
Wire the throttle cable to the carburetor
in the same way as a stock cable. Fix thecarburetor top to the throttle cable, andinstall the inner cable to the throttlevalve while compressing the throttle
valve spring.

PY

Processing Throttle PipeCramp

Wire harness

Socket cap screw○ In case a stock housing is used in thevehicles with frame number Z50J-1300017
to 1510400, rasp the shaded part of thethrottle valve as indicated in thefigure below○ As for the vehicles with frame numberZ50J-1600008 or above, there is no needto process as above.
Throttle pipe

○ Mount the throttle valve to the carburetoraligning the notch on the throttle valve
with the throttle stop screw.
NotchThrottle stop screw○ Adjust the adjuster of a throttle cable sothere is approx. 5 mm of free play at thethrottle grip.
Open up the throttle a few times to check
whether it moves smoothly without suddenly
stopping, and also to check whether thethrottle valve is fully open.
※ Check that there is a little free play at
the throttle even when you turn the steering
handle all the way to the left and right.
about 5mm

2022.2.7

03-05-0244,03-02-052

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・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:

When the air-fuel mixture is too lean:

・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.

・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.

CO※ Set the carburetor only after warming up the engine, and then test-drive. And use a plug with the right heat value.
※ Do the setting in the following manner, studying at what throttle opening position the engine starts failing.

○ Jet needle (Throttle position at 1/4 - 3/4)
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.

3rd groove
2nd groove
4th groove

1st groove

5th groove○ Main jet (The throttle position at 3/4 - 4/4)

PY

・The air-fuel mixture ratio at this throttle position can be adjusted by changing the number of the main jet. The larger themain 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.

○ Slow jet / 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 slow jet / pilot jet with a small number.
・If you have tighten the air screw (clockwise) to the full, use a slow jet / 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 theidling to running at slow speed.
・When the engine revolves up unevenly, the slow jet / pilot jet number is too small. (At idle)
・When the motorcycle belches black exhaust gas and produces heavy exhaust sound, the slow jet / pilot jet number is too big. (At idle)
・After replacing the slow jet / pilot jet, you need to readjust the airscrew.

○ Air screwThe 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 lessamounts.
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.

CONTACT Address : 3-5-16 Nishikiorihigashi Tondabayashi Osaka JAPANTEL: +81-721-25-1357 FAX:+81-721-24-5059 e-mail:english@takegawa.co.jp URL http://www.takegawa.co.jp
Please contact with your name and country name provided. (Only English please)2022.2.2