Takegawa Mikuni VM26 User manual

COPY
‑1‑ Apr./28/06
Instruction Manual for Mikuni VM26 Carburetor Kit
・Thank you for purchasing one of our TAKEGAWA's products. Please strictly follow the following instructions in installing and using the products.
・Before fitting the products, please be sure to check the contents of the kit. Should you have any questions about the products, please kindly contact
your local motorcycle dealer.
Please read the following before starting the 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 kind of warranty whatsoever of products other than this product if the glitch takes place on the other products than
this one after the installation and use of this product.
◎This carburetor kit is for exclusive use in our own bore-up kit and bore-stroke up kit. This kit is not compatible with a stock engine or a stock head.
◎Do the installation work correctly referring to the relative Honda’s genuine service manual for the above-mentioned applicable models with frame
numbers.
◎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 models.
◎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.
◎This kit does not use a stock throttle housing. You are requested to prepare a brake lever, etc by yourself.
◎As this product is designed for exclusive use in the closed racing, do not drive on the public road with this kit installed on the motorcycle.
◎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.
Item No.：０３―０５―０４８３
Applicable Models and Frame Nos:
Monkey / Gorilla：Z50J-2000001〜
：AB27-1000001〜
・Work only when the engine and 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. (Otherwise, improper tightening 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 worn or damaged parts,
replace them with new ones.
The following show the envisioned possibility of injuries to human bodies and property damage as a result of disregarding the
following cautions.
Caution
・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, stop riding immediately and park your motorcyle in a safe place.
(Otherwise, the abnormality could lead to accidents.)
・Before doing work, make sure your bike is secure 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 your motorcycle correctly according to the procedures in the instruction manual or 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.)
The following show the envisioned possibility of human death or serious injuries to human bodies as a result of disregarding the
following cautions.
Warning
◎Please note that, in some cases, the illustrations and photos may vary from the actual hardware.

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‑2‑ Apr./28/06
No. Part Name Qty Repair Part Item No. Qty
1Carburetor assembly 103-03-0321 1
2Inlet pipe 117114-GEF-T00 1
3Insulator 116212-165-T00 1
4Insulator band 100-00-0050 1
5Insulator pipe gasket 100-03-0009 3
6Cap screw 6 x 15 200-00-0042 10
7Cap screw 6 x 20 100-00-0043 10
8Cap screw 6 x 50 100-00-0044 3
9Fuel cock 103-03-001 1
10 Air filter 103-01-1064 1
11 Throttle COMP. 1
12 Throttle cable, 810 mm 109-02-0081 1
13 Throttle grip set for right and left R / L 09-02-0002 R / L
14 Fuel hose, 200 mm 100-03-0203 1
Main jet # 180 100-03-0076 1
Main jet # 185 100-03-0077 1
Pilot jet # 17.5 100-03-0154 1
Pilot jet # 20 100-03-0155 1
Hex wrench, 5 mm 1
☆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.
☆A stock air cleaner cannot be equipped together with this carburetor kit. The engine will go wrong if the engine gets wet. So, please refrain from running
in the rain. Besides, before washing your vehicle, cover the carburetor with a plastic sheet or the like to prevent water from getting into the carburetor.
〜Kit Contents〜
１２
４
７８
５
３
６
９
１０
１４
１１
１２
１３
０９―０２―０２２１
Main jet #190
Pilot jet #22.5
Jet needle 5E75
Clip position 3rd groove from top
Throttle position #1.5
Air screw opening １turn ±1/4
Factory preset mode of the carburetor
Option
Throttle cable, 710 mm
０９―０２―００７１
Item No. Product Name
00-03-0151 #10
00-03-0152 #12.5
00-03-0153 #15
00-03-0154 #17.5
00-03-0155 #20
00-03-0156 #22.5
00-03-0157 #25
00-03-0158 #27.5
00-03-0159 #30
VM26 Pilot Jet Item No. Product Name Item No. Product Name
00-03-0060 #100 00-03-0074 #170
00-03-0061 #105 00-03-0075 #175
00-03-0062 #110 00-03-0076 #180
00-03-0063 #115 00-03-0077 #185
00-03-0064 #120 00-03-0078 #190
00-03-0065 #125 00-03-0079 #195
00-03-0066 #130 00-03-0080 #200
00-03-0067 #135 00-03-0081 #210
00-03-0068 #140 00-03-0082 #220
00-03-0069 #145 00-03-0083 #230
00-03-0070 #150 00-03-0084 #240
00-03-0071 #155 00-03-0085 #250
00-03-0072 #160 00-03-0086 #260
00-03-0073 #165
VM26 Main Jet
※Please note that in ordering repair parts, be sure to quote the Repair Part Item No. Otherwise, we may not be able to accept your orders.
There are some parts, however, for which we are not in a position to accept your order in just the quantity to be used. In this case, please
take them in the quantity packed.

COPY
‑3‑ Apr./28/06
○Adjust the setting to meet the
motorcycle in a safe place with
utmost care.
○Put a inlet pipe gasket between the
cylinder head and the inlet pipe, and
tighten the inlet pipe with 6x20 and
6x50 socket cap screws.
Specified torque
:10 N・m (1.0 kgf・m)
○Fasten the insulator to the inlet pipe
with two socket cap screws.
Specified torque
:10 N・m (1.0 kgf・m)
○Detaching the top cover from the
carburetor of the kit, pull out the
spring and throttle valve. Pass the
inner cable of the throttle cable
through top cover and then put in
the spring. And attach the inner cable
to the throttle valve, compressing the
spring. Then align the notch on the
throttle valve with the throttle
stopper screw, which please attach
to the carburetor.
○Put the carburetor into the insulator,
and fasten it with a clamp band. ○Insert a fuel tube and fasten it with a tube clip. Open the fuel cock and
ckeck for oil leaks. (Do not leave
the cock open over a prolonged
period of time.)
○Pull a choke lever to start the
engine. Gradually loosen your grip
on the lever back, and warm up
the engine till the revolution
becomes smooth. And then return
the lever fully back into its original
location. If the engine does not run
idle after warming-up, or it runs
idle at high revolutions, adjust the
revolutions with the throttle stop
screw.
〜Installation Procedures〜
○Unfasten the inlet-pipe-tightening
bolt and air-cleaner-mounting
bolts. Remove a throttle valve from
a carburetor. Then remove the
carburetor with the air cleaner box
and the inlet pipe and all.
※Be careful not to let any foreign
substance into the intake port.
○Confirming that the fuel cock is
shut off, open a drain cock on the
carburetor to drain gasoline from
the float chamber onto an oil
container.
Before installation, check the kit
contents.
○Unfasten the pan screws on the
throttle housing and remove the
throttle housing.
○Remove the throttle valve from the
carburetor, and separate the
throttle valve from the throttle
cable. Then pull out the top cover
from the throttle cable.
○Hold the earth cable to the frame
with an air-cleaner-mounting bolt.
○Attach an air filter, and hold it by
tightening a band.
○Adjust the free play at the throttle
grip to be about 5 mm by turning the
adjuster of the throttle cables.
Snap the throttle a few times to make
sure that the throttle moves smoothly
and that the throttle valve is fully
open. Also check that the throttle has
free play even when the steering
handle is turned all the way to the
right and left.
※In case of installation to any models
of Gorilla, replace the preinstalled
fuel cock with the kit's cock. Adjust
the direction of the fuel cock and
fasten the nut to the fuel tank.
Specified torque
:5 〜6 N・m (0.5 〜0.6 kgf・m)
○Dispose of the blow-by gas from
the crankcase by yourself. In
some cases, racing and
regulations stipulate the disposal
of the blow-by gas.)
○In case of returning the blow-by
gas to the carburetor, return the
blow-by gas to the union of the
air filter.
(Installation)
◇Run a throttle cable of the kit under
the frame.
◇Pass the throttle cable of the kit
through the lower throttle housing,
and connect the inner cable to the
throttle pipe. Fasten the throttle
housing to the handle with two
screws.
※Apply grease to the rubbing
surface and cable end of the throttle
pipe, and cable-widing portion on the
pipe.
Specified torque
:5 N・m (0.5 kgf・m)
○In the case of the Gorilla and
Monkey BAJA, remove a seat,
drain gasoline in the fuel tank, shut
the fuel cock, pull out the fuel hose
on the carburetor side, and then
remove the fuel tank.
(Preparation for Installation)
Caution: Make sure that engine
and muffler are cool and
that the motorcycle is
secure!!
Caution: Be sure to tighten to the
specified torque with a
torque wrench!!
Inletpipe Insulator
Inlet pipe gasket
Adjuster
More free play
Less free play
About 5mm
3-5-16 Nishikiorihigashi Tondabayashi Osaka Japan
TEL : [phone] FAX : [phone] URL : http://www.takegawa.co.jp
Co.,Ltd.

COPY
Aug./20/09
How to Set the Carburetor
※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.
○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.
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.
◎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.
・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:
1段目
3段目 4段目
2段目
5段目
1stgroove
2ndgroove 3rdgroove 4thgroove
5thgroove
3-5-16 Nishikiorihigashi Tondabayashi Osaka Japan TEL:[phone] FAX:[phone] URL:http://www.takegawa.co.jp
Co.,Ltd.