S-Stage Bore Up Kit 88cc SCUT Instruction manual
Product number

01-05-5095 (With camshaft)
01-05-5098 (Without camshaft)Monkey & Gorilla

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

～ feature ～○ Now kit is available from us which can bore up to 88cc with anormal 55cc cylinder head installed. Thus, with this kit you canenjoy the feeling of a heavy engine. We have developed this kit
as a street youth kit which you can assemble as easily as aplastic model and with which you can study the engine structure.

CO(Z50J-2000001 ～ )(AB27-1000001 ～ 1899999)
Monkey BAJA
all vehicles
JAZZ
all vehicles
MAGNA50all vehicles
Benly CD50/CL50/50S (CD50-1500001 ～ )Dax(AB26-1000001 ～ )(C 50-9000001 ～ 0095210)
Adaptation model Super cub 50(C 50-0200001 ～ 0999999)(C 50-2100001 ～ 2299999)(AA01-1000001 ～ 1699999)
Little cub(C 50-4300001 ～ )(AA01-3000001 ～ 3699999)
Giorcub(AF53-1000001 ～ )XR50R
all vehicles
CRF50F(AE03-1400001 ～ 2299999)

About fuel to use

This S-Stage Kit is so designed to achieve a higher compression ratio than stock engines. Therefore, high-octane gasoline should
always be used. In case regular gasoline is used, you cannot get the performance of this Kit. Moreover, it is possible that thepiston will be damaged, leading to a serious failure of a motorcycle. Before installing this kit, make sure that no regular gasoline
remains in the fuel tank. In case regular gasoline is remaining in the fuel tank, do replace it with high-octane gasoline.

About the spark plug

Be sure to replace a spark plug with a CR8HSA (NGK) or U24FSR-U(DENSO). In the case of a non-resistive plug, please replace with C8HSA (NGK)or U24FS-U (DENSO). Subsequently, choose and use a right spark plug with the right grade, depending on the carburetor set up.

Notice about sprocket

The installation of this Kit will increase the power of your engine. So with the stock sprocket, every hardware will get worn out
soon because of too low gear, not only adversely affecting the engine life, but also possibly breaking the engine in the worst case.
Therefore, judge the right type of a driven sprocket.

☆ Please read carefully before use ☆

◎ We do not take any responsibility for any accident or damage whatsoever arising from the use of the kit 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 theother products than this one after the installation and use of this product.
◎ If you make modifications to any product of the kit, we shall be held free from any guarantee of the product.
◎ You are requested not to contact us about the combination of our products with other manufacturers’.
◎ Please note that this kit is designed for exclusive use in the above-mentioned fitting models and frame numbers only and that it
cannot be mounted on any other models.
◎ For installation, please prepare suitable tools and work with reference to the installation instructions with enough care. Besides, this
instruction manual,as well as a service manual, is prepared with those persons in mind who have basic skills and knowledge. Therefore, we
recommend those who are technically inexperienced or do not have enough tools to ask a technically-reliable specialist shop for the work.
◎ As this Instruction Manual is prepared mainly for installation on the Monkey, so some portions of this Instruction Manual may not
apply to installation on other models than the Monkey.
◎ Bolts,nuts and dowel pins will be reused. However,be sure not to use the worn-down or severely-damaged ones, which please do replace with new ones.
◎ If you use a stock carburetor, do not remove the air cleaner box or air cleaner elements. If you change the carburetor, please do the setting
to match various conditions like weather and temperatures. Disregarding these instructions will result in engine troubles and serious accidents.
◎ In the case of a motorcycle with an engine starter, in some cases the engine won’t start with the engine starter even when thebattery is fully charged.
◎ The JIORCUB may interfere with the starter motor and cylinder with this product. Check when installing and repair the cylinder if
there is interference.
CautionPY

When the handling of ignoring this display, property damage and human shows the assumption of what injury.

■ Please drive safely and follow the local traffic law.
■ Work only when the engine and exhaust system are cool to avoid burns.
■ Prepare appropriate tools and work properly to avoid the breakage of parts or injuries.
■ Always use a torque wrench to tighten bolts and nuts securely to the specified torque to avoid these parts getting damaged or loose.
■ As some products and frames have sharp edges or protruding portions, work with your hands protected to avoid injuries.
■ Before riding, always check such parts as screws for loose. If you find loose ones, screw them securely up to the specified torque to
avoid parts coming off.
■ Always use new gaskets and seals. About the reused parts, please check carefully for wear or damage and be sure to replace them withnew ones if necessary.
Warning When the handling of ignoring this display people died, shows the contents of the serious injury possibility is
assumed.
■ Always start the engine in a well-ventilated place, and do not turn on the engine in an airtight place.
(Otherwise, you will suffer from carbon monoxide poisoning.)■ When you notice something abnormal with your motorcycle, stop riding immediately and park your motorcycle in a safe place to avoid an accident.
■ Before working, place the motorcycle on level ground to stabilize its position for safety to avoid the motorcycle overturning.
■ 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 inspecting or performing maintenance of your motorcycle, do not use these parts, and replace them withnew 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. (Otherwise it may cause a fire.)
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)2023.6.5

01-05-5095,5098

/12◎ 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 in
racing and the like.
◎ Keep this manual stored until this product is discarded.
Product content

01-02-517:Piston kit①

01-13-0608:Gasket kit

②
⑥

⑦

⑫
③

⑬

⑤

⑧

⑩

⑨

⑪

⑮

⑭

④

CO

NumberProduct content
Quantity
Item Number
1
Piston100-01-0014 (with ③ pin)2
Piston ring1
01-15-014
3
Piston pin, 13x36
100-01-0091 (with ④ clip)
4
Piston pin circlip
200-01-0003 (6 pcs)
5
Cylinder
101-01-0241H
6
Cylinder head gasket
100-00-1147
7
Cylinder gasket
100-01-0067 (2 pcs)
8
Head cover gasket
100-01-0156 (2 pcs)

NumberProduct content
Quantity
Item Number
9
Right-side cover gasket
100-01-0157 (2 pcs)
10 Left-side cover gasket
100-01-0158 (2 pcs)
11 Tappet cap O-ring
2
00-01-0034 (4 pcs)
12 Exhaust pipe gasket
100-01-0064 (2 pcs)
13 Rubber seal
100-01-0066 (2 pcs)
14 Inlet pipe gasket
100-01-0159 (2 pcs)
15 Camshaft
1
01-08-0009※ A camshaft of No. 15 is not included in Item No. of 01-05-5098.
※ 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.

Before starting the installation● Before starting the installation, secure your motorcycle firmly on level ground for safety's sake. It is recommended to use thecenter stand for the Super Cub 50. and the racing stand for the monkey. rather than supporting the vehicle with the built-in sidestand. This will ensure your safe work with your motorcycle being firmly secured.
● Do the installation work with the engine turned off and, moreover, work only when the engine and muffler are cool.
● Turn off the fuel cock.
● At the time of removal of hardware like bolts and nuts which are to be reused, clean every hardware by taking off all dirt like thedust and oil on each hardware.
● Don't lose such removed hardware as bolts and nuts, and keep them orderly so you can recall where to fix them later.

About tools

PY● Incorrect use of right tools may lead to breakage of the top or thread parts of hardware like bolts and nuts.
● The correct and suitable tools are all the more necessary for those with no experience with installation. At the same time, it isalso necessary to experience the right use of the tools. It is advisable, therefore, that if you are not well prepared for the
installation, you get in touch with a technically trustworthy dealer for the installation.
● For your reference, listed below are the tools to be used for the installation of this Kit. Please be advised, however, that thetools may vary depending on the motorcycle models and the model years.
※ Even if the names of tools are the same, the tools vary from maker to maker, and the kinds may also differ. On the other hand, even
if the tools themselves are the same, the names may differ among makers. And, users may have their own taste. Therefore, make use of
the following list just for your reference inly.

3

1

5

4

2
10

6

11

7
12
8
9

13

14

17
15 16

1
2
3
4
5
6
7
8
9

Torque wrench
Plastic hammer
Scraper
Tappet adjust wrench
Thickness gauge
Open-end wrench, 8-10
Offset box wrench, 8- 9
Offset box wrench, 10-12
Offset box wrench, 14-17
Cross tip screwdriver,10
size 1

18

11

12
13
14
15
16
17
18

Fine-shaft flat tip
screwdriver
Extension, (medium)
Extension, (small)
Spark plug socket, 16mm
Socket, 8mm
Socket, 10mm
Socket, 12mm
Ratchet wrench
Waste clothEngine oil(only for applying)

About bolts● Usually, counterclockwise rotation loosens the bolts and nuts, and clockwise rotation tightens them.
● When tightening a screw, at first finger-tighten it as tight as you can, without using a tool.
● To loosen a tightened screw means turning it three or four times counterclockwise, and to remove it means turning it aroundcounterclockwise until it comes off.
● To tighten a screw means to tighten it to keep it from getting loose. However, the bolts may break when overtightened, or may getloose or come off because of the vehicle's vibrations when tightened too loosely. The numeric value as a guide at which a screw will
not break or get loose when tightened is the specified torque. And the numeric value varies among the size of the bolts.
● If you do not have a torque wrench, please try to tighten a screw as tight as possible to the extent that the screw will not break or
get loose, though we can not take any responsibility for the screw's breakage or getting loose. In case you do not use a torque wrench,
you need to judge, only by intuition or using experience, the degree of tightening power with which the screw will break or get loose.
2023.6.5

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2023.6.5

01-05-5095,5098

/12Exhaust pipe gasket

Tappet adjusting hole cap

O-ring, 30mm

Cylinder head cover gasket

Hex nut,, 6mm

Sealing washer A, 6 mm
(Copper plated)

Camshaft COMP.

Spark plug ※ 3

Dowel pin, 8x14 ※ 1

Cylinder head gasket

Inlet pipe gasket

O-ring, 30mm

Tappet adjusting hole cap

PY
※1
※2
※3

Knock bolt, 5mm
Left-side Cylinder headside cover gasket
Left-side Cylinder headside cover

Dowel pin, 8x12 ※ 1

Cam sprocket※2Bolt, 6mm

Cam chainguide roller COMP.

Dowel pin, 8x14 ※ 1

Bolt, 6mm

washer, 8mm

Guide roller bolt

Dowel pin, 8x12 ※ 1

Cylinder gasket

Rubber seal, 16mm

PistonPiston pin

Piston pin clip

Piston ring set

CylinderThere are several kinds of length for dowel pins.
Please make sure of the size before installing.
These hardware is not included in the kit orwill not be used for the installation of this kit.
Be sure to use CR8HSA (NGK) or U24FSR-U (DENSO).

COCap nut, 6mm

Sealing washer, 6mm

Cylinder head cover

Valve rocker arm

Tappet adjusting screw

Tappet adjusting nut

Valve rocker arm shaft

Flange bolt, 6x20

Flange bolt, 6x110(Copper or a aluminum)
sealing washer, 6.5 x12

Right-side Cylinder headside cover

Right-side Cylinder headside cover gasket

Part names

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

Before riding① Change of sprocket◇ The installation of this kit will increase the power of your vehicle. So with the stock sprocket, you will find it uncomfortable todrive your bike because the gear ratio is too low, and will cause severe wears of hardware, not only adversely affecting the engine
life, but also possibly breaking the engine in the worst case. Therefore, please replace the drive and driven sprockets to make thegear ratio higher.
※ Please note that a driven sprocket is not included in the kit.
※ Furthermore, the gear ratio of the sprocket changes according to the clutch type and wheel size. The list below is just for yourreference because the configuration in the list below needs to be changed according to the driver’s weight and purpose of use.
※ When changing the driven sprocket, remove hardware around the rear wheel. Raise the rear wheel off the ground by placing amaintenance stand under the engine for working safely.

Recommended sprocket for use with S-Stage,(With camshaft)(with a driver weighing 65 kg)

CO
ModelsSpecifications

Rear wheel size
8 inch

12V Monkey and Gorilla

10 inchClutchTransmission

ManualHeavy-duty special
ManualHeavy-duty special
ManualManual4-speed
4-speed
4-speed
4-speed
4-speed
4-speed
4-speed
3-speed
4-speed
3-speed
4-speed
3-speedBenly CD50/CL50/50S
MAGNA50
Giorcub
12V Dax

17 inch

10 inch
10 inchCentrifugal
Centrifugal

Super cub 50

17 inchCentrifugal

Little cub

14 inchCentrifugal

Recommended Sprocket
Drive sprocket
Driven sprocket(Front)(Rear)
16
23
16
25
16
25
16
28
16
42、43(Stock)
16
33
16
31
16
31
16
42(Stock)1635
1641(Stock)
16
35

PY

◇ When the stock sprocket is changed to the recommended driven sprocket, the drive chain becomes too slack or too short. However,
it is impossible to take up the slack of the drive chain just by adjusting the free play. You need to either shorten the chain by
cutting it with a chain cutter, or to prepare a new drive chain. Especially, in the case of the Monkey, the length of chain changes
according to the length of swing arm.

② About fuel◇ High-octane gasoline should always be used.
◇ If there remains regular gasoline in the fuel tank, always replace it with high-octane gasoline.
◇ Please use this kit at STD.ignition timing. Please note that we hold no responsibilities for accelerating the ignition timing.

For best performance① Camshaft③ MufflerThis is the recommended part to install with 01-05-5098 (without acamshaft). Our super sports camshaft can effectively bring out theoriginal performance of the bore up.kit.

Recommended Camshaft
Super sports camshaft(01-08-0009)
Super sports decompression camshaft (01-08-0069)

The installation of this kit increases the heat release value ofthe engine, set off by the increase in power. The installation ofSuper Oil Pump is essential in order to circulate large amounts ofoil and to help cool hardware and to alleviate the burden.

ModelsMonkey and Gorilla
Benly CD50/CL50/50S
MAGNA50
Giorcub
DAX
Super cub・Little cub

Higher power can be attained through the installation of Big Bore
Carburetor Kit suitable for each model of a bike for the best
performance of S-Stage.

Recommended Big Bore Carburetor Kit

Super cub・Little cub④ Oil pump

Recommended Oil Pump

② Carburetor

ModelsMonkey and Gorilla
MAGNA50
DAX

Please install our various kinds of exhaust system for higher
power output.

Carburetor Kit(03-05-0056)
DENI18(03-05-0054)
Big Carburetor(03-05-0057)
PB16(03-05-0116)
Big Carburetor

01-05-5095,5098

01-16-0066(with drill bit)
01-16-0065(without drill bit)

⑤ Oil cooler
As a longtime high-load driving will further increase the heatrelease value of the engine, we recommend you to install an Oil
Cooler Kit which keeps oil at appropriate temperatures andprevents such troubles as oil film shortage at high temperatures.

○ For details, please refer to our general catalog or WEB catalog.
http://www.takegawa.co.jp
2023.6.5

Super Oil Pump

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

● Removal of the exteriorparts◇ Disconnect the fuel and air
hoses.

＜ Monkey ＞◇ Open the drain cock and drain
the gasoline from the float
chamber to the tray.

Fuel hose◇ Remove two hex bolts on thereverse side of the front fender.

Warning: Be careful whenhandling gasoline.

Drain cock＜ Cub ＞CO

◇ Remove A, B, C cap nuts,bolts,
washers,plates,setting collars.
Do the same to the left side
as well.

◇ Disconnect the two wires of
the carburetor heater (whenequipped).

◇ Close the drain cock afterdraining the gasoline.
◇ Remove the two screws on the fuelcock and remove the fuel cock.

Air hose◇ Disconnect the horn wiring.

C◇ Disconnect the hose on thestorage tank in the case of
bikes with frame Nos AB27-.

A◇ Remove two bolts holding thecylinder head and inlet pipe.

B◇ Remove the air vent hose fromthe frame.

◇ The leg shield is easy toremove if you first remove thefront part of the vehicle andtilt it to the side.

◇ Loosen the bolt on the aircleaner bracket.

◇ For Little Cub,remove theskid plate together with thesetting collar by removing
the hook part of the step bar.

Step bar
Skid plate hook part

PY
◇ Remove the breather hose(chassis No. AA01) whichconnected to the storage tank.
※ Since the format differs dependingon the vehicle, refer to thefigure below and extract it.

◇ Remove two bolts holding thecylinder head and inlet pipe.
◇ Hang a carburetor assembly
onto the turn signal in thefront on the left, with thethrottle cables connected.

◇ Remove the duct by pulling
upward.

◇ Remove the air cleaner bolts
on both the left and rightsides.

◇ Remove the belt bundlingwires.

● Remove the carburetor＜ Monkey ＞＜ Cub ＞

◇ Turn off the gasoline cock at
the lower left of thegasoline tank.

◇ Turn off the gasoline cock at
the lower left of the
carburetor.

◇ Remove the carburetor ASSY.
attached with throttle cables
and choke cables and hang on
the front-left turn signal.
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■ Mounting procedure※ Please refer to the Genuine Service Manual for detailed mounting methods and specified torques that are notspecifically described.

● Remove the exhaust system ◇ Remove the flange nut / washer＜ Monkey ＞◇ Remove three bolts which are
holding a crankcase left-side
cover.

of the exhaust bracket.

◇ Remove two nuts on theexhaust pipe.

◇ Remove a hex bolt which isholding a muffler.

◇ Remove the exhaust system bypulling outwards. Do not losethe exhaust pipe gaskets.

COWith electric starter models＜ For Cub with self starter
motor ＞
◇ Remove the timing hole cap andcrankshaft hole cap.

The timing hole cap● Remove the spark plug

◇ Remove a nut fixed on thereverse side of the muffler.

◇ Detach two collars of the flange
and then remove the exhaustsystem from the motorcycle bypulling it outwards.

◇ Holding a flywheel, remove twohex bolts on the cam sprocket.

◇ Remove the plug cap from the plugby pulling it out. Be sure to
hold the cap in pulling it out.
◇ Remove the plug with a plug wrench.

Crankshaft hole cap◇ Prize the cam sprocket fromthe camshaft with a small-sized
flat tip screwdriver to remove it.
◇ Remove the cam sprocket fromthe cam chain.

◇ Remove two tappet caps.

PY● Remove the cam sprocket◇ The left-side cover will become
separated when the hex bolt inthe middle of the cylinder-headright-side cover is removed.
In case the left-side covercannot be detached by so doing,screw in the hex bolt by a few
threads, and strike the bolt
head with a hammer lightly.
Then the bolt will get separated.

◇ Detach the dowel pin fixed in
the center of the camshaft.

◇ Turn the flywheel counterclockwise
so a “T” mark on the flywheel
and “O” mark on the cam
sprocket align with their own
notches.
Notch● Remove a cylinder head,
cylinder and piston

Stamped “O”mark◇ Remove the side bolt on thecylinder head, which is holding
the cylinder head and cylinder.

Notch

Flywheel＜ Cub ＞
◇ Remove two nuts on theexhaust pipe.

◇ Unfasten a hex bolt on the shiftpedal and remove the change pedal.

With electric starter models◇ Loosen a guide roller bolt on thecylinder and a side bolt between
the cylinder and crankcase.
Guide roller bolt

Side bolt

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

◇ Remove four nuts, which are
holding the cylinder-head cover,by turning them alternately
and diagonally.
◇ Remove four washers beneathnuts.

◇ Remove the loosened guide rollerbolt and cylinder side bolt.

◇ Remove the piston pin in the
direction where the piston
circlip is not attached.
You can easily remove the piston
pin by pressing it with a flat
tip screwdriver from the direction
where a piston pin circlip is
attached.

◇ Pull out the cylinder.
(If it is hard to pull it out,
hit the cylinder lightly with aplastic hammer.)CO◇ Remove the head cover.
(If it does not come off easily,
strike it lightly with a plastic
hammer, and it will come off.)If some gaskets remain on thecylinder head,wipe them offcompletely with a scraper.

Monkey◇ Remove the cylinder head fromthe cylinder by pulling thehead away from the cylinder.
(If it does not come off easily,
strike it lightly with a plastic
hammer, and it will come off.)◇ For monkey,pushing the front
tire rubber.(to make space)then remove the cylinder head.

◇ For monkey,pushing the tirerubber.(to make space) thenremove the cylinder.

◇ Remove the piston.

◇ Remove the cylinder gasket andrubber packing.
◇ If the gasket does not comeoff cleanly、use a scraper toremove.
◇ If the crankcase center gasket
protrudes from the cylinder basesurface or the cylinder hole,cut it off.
※ Never let any dirt, dust or
hardware into the crankcase.

1.Cover the crankcase securely
with a waste cloth so theshavings will not get into it.
2.Rasp the higher mating surfaceof the crankcases till it
becomes level with the lower
one.
Right side
crankcase

PY

Left side
crankcaseGasketCylinder gasket◇ Plug the cylinder hole in the
crankcase with a waste cloth soas never to let the dirt, dustor hardware into the cylinderhole and cam chain.

◇ Remove one of the two piston pin
circlips. You can remove it byprising it open with a screwdriver
tip being placed on the notch.

01-05-5095,5098

Interfering portion

CylinderRubber seal

◇ Cut off the gasket, if any,squeezing out into the section
pointed by a finger as shown in
the picture.

Piston pin circlip

2023.6.5◇ Attach two dowel pins to the
crankcase and install thecylinder unit to the crankcase.
Check for interference
between the crankcase and thecylinder sleeve.
◇ The following is an example
of correction when the left
and right crankcase matingparts interfere.
Sleeve◇ While removing the cylinder,the cam
chain guide roller will come out.

◇ For monkey, air bleeding fromthe front tires.
(Push the air valve until the
bleeding air all.）● Check and correcting(if necessary) crankcase
interference.

/12

After being
fixed

3.After scraping, remove thecloth with enough care so any
chip will not get into thecase.
4.After removing the waste cloth,
stuff up the crankcase opening
with a clean waste cloth.
5.After the installation of theKit, idle away the engine fora few minutes, and replace
the engine oil with new one
without delay.
And there is nothing more to do.

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

● Assemble and install apiston◇ Put the oil ring expander.

◇ Fix the piston so the arrow on
the piston head faces downward,
or to the exhaust side.

◇ Fix a supplied piston pin
circlip securely to the grooves
for circlip on one side of
the piston.
At this time, attach the piston
pin clip, do not align the end
gap with the piston cut out.

◇ Insert the cylinder.

◇ Fit in the cylinder, taking careso that the piston ring-end gaps
do not get out of position.

Exhaust sideCO◇ It will also be an easy way of
installing the piston to first
insert the piston pin about one
third into the piston.

◇ Put the lower oil ring side rail.

Piston◇ Once the ring has been placed
inside the cylinder,pass thecam chain through the cylinder,and fix the cylinder into the
crankcase.

Circlip
end-gap

Notch

Left
side

◇ You can rather easily install
the piston pin circlip bypressing
it with a screwdriver, but
taking care not to damage thepiston with the screwdriver.
◇ Apply engine oil to thepiston-ring grooves, and fix
piston rings in the order of an
oil ring expander,lower oil ringside rail, upper oil ring side
rail,second ring and top ring.
◇ Arrange the positions ofpiston ring-end gaps so theymesh with each other.

◇ Put the upper oil ring side rail.

◇ Insert the second ring withthe mark side facing up.

Mark◇ Insert the top ring with themark side facing up.

Top ring

Mark

120°
120°

120°

◇ Pulling the cam chain, fix theguide roller.

PY
PistonCirclip
end-gap

Notch◇ You can rather easily install
the piston pin circlip bypressing it with a screwdriver,
but taking care not to damage
the piston with the screwdriver.
※ Do the work carefully as,in somecases, the circlip comes off flying
while you are pressing it inside.
◇ Remove the plugged waste cloth.

◇ Press in the guide roller so thecenter of the guide roller andthe guide-roller bolt hole on
the cylinder just mesh together.
Install the sealing washer
and guide roller bolt.
(Finger-tighten it only for now.)● Installation of cylinder

Second ring

Side
rails

Expander◇ Fix securely the supplied piston
pin circlip to the circlip groove.
At this time, attach the piston
pin clip, do not align the end
gap with the piston cut out.

60° 60°◇ Apply engine oil to the piston
pin and con’rod, and install
the piston pin.

◇ Degrease the cylinder andcrankcase for base gasket
surface with parts cleaner etc.
◇ Make sure 2 dowel pins B(L:12 mm)
are attached,and install cylinder
gasket with 1 o-ring (black).
Cylinder gasket

Dowel pin

Stamped on the top ringand the second ring.

Rubber seal(Black）◇ Apply engine oil onto the insideof the supplied cylinder andspread the oil evenly with fingers.

Top ring(silver side)
Second ring
(Black)Side rail

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(Fasten it only finger tightfor now at this point.)

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

● Change of camshaft◇ Loosen the adjust nuts andbolts on the rocker arm
installed in the cylinder head.
At the time the adjust nuts
are loosened, detach the tappet
bolts together with nuts.

● Installation of cylinderhead◇ Degrease the cylinder head surface
and upper surface of the cylinder.
◇ Attach two dowel pin A(L:14 mm)
and cylinder head gasket to thecylinder.

◇ Install the cylinder head with
washer.(A copper washer installon the lower left (when looking
from the riding position).）● Installation of cam
sprocket◇ Align the “T” mark on the
flywheel with the notch on the
crankcase.
Notch

Cylinder head gasket

Copper washer

CO◇ Install the head nut.(A hex
nut install on the lower right(when looking from the riding
position).）Dowel pin

◇ Install the cam-sprocket bolt
into the camshaft. The camshaft
will come out when you pull it
out or strike its head lightly
with a plastic hammer. Turning
the camshaft, detach it.
Do not pull it out by force.

＜ For Cub with self starter
motor ＞◇ In the case of a monkey, push
the tire rubber by hand (to makespace) and install the cylinder
head through the stud bolt.
◇ Passing the cam chain throughthe cylinder head,install thecylinder head.

With electric starter models

Hex nut◇ Tighten the head nut
diagonally in several steps.
Note: Be sure that you protect
specified torque.
Head nut

Torque：11N・m（1.1kgf・m）◇ Hold the cam chain by sticking
the screwdriver through the cam
chain into a middle hole on thecamshaft so the cam chain will
not fall into the cylinder.

◇ Apply clean engine oil to thecamshaft and bearing parts.
Apply oil

◇ Set the shaft so the cam top
faces the piston when the cam
sprocket bolt hole is turned
toward the notch on the cylinder
head. This arrangement places
the cam shaft at TDC (Top Dead
Center) on the compression
stroke.
※ In installing the optional cam,please refer to its instruction
manual.

PY◇ Install the side bolts of thecylinder head and tighten thetemporarily fixed guide roller
bolts and the side bolts of thecylinder.

◇ Attach the cylinder-head covergaskets and head cover.

Note: Be sure that you protect
specified torque.
Guide roller bolt

Torque：10N・m（1.0kgf・m）

Lower and upper side bolts

Torque：10N・m（1.0kgf・m）◇ Install the dowel pin to thecamshaft.

Apply oil

◇ Install the supplied camshaft
in the reverse order of removal.
Even if you cannot easily fix thecamshaft, fix it manually without
striking it with a hammer.

◇ Remove the hex bolt next tothe change-pedal shaft.
Loosening the tensioner
pulling the cam chain makes
it easier to install it.

◇ Tighten the adjust screw andadjust nut on the rocker arm.

◇ The arrow should face downwar(Exhaust side).

Oil will flow out a little after
the bolt is tightened. Wipe off
the oil.

Arrow showing which sideshould face downward.

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

◇ Attach the cam chain to thecamshaft so the“O”mark on the
cam sprocket and the notch on
the cylinder head mesh together.

◇ After installed the cam
sprocket, attach the bolt.

● Valve timing adjustment
and tappet clearance
adjustment

Adjust screw◇ Turn the flywheel until the“O”
mark on the cam shaft and the“T”mark on the flywheel meshwith each notch. Though the
flywheel will not stop right at
the required position because
the magnet force repels eachother,it is all right if“O”
and“T”marks mesh with eachnotch at the same time.

◇ Attach the cylinder-head
left-side cover gaskets andleft-side cover.
（Align the tab on the L side
cover with the stopper in thecylinder head.）Thickness gauge
Valve stem

Notch

CO

Stamped“O”mark◇ Holding the flywheel, tighten
up two cam sprocket bolts.

Note: Be sure that you protect
specified torque.
Cam sprocket bolt

Cylinder head side

◇ After adjusting the tappet,turnthe flywheel counterclockwise
twice by hand, and then, align“T”and “O”marks each other.

Notch

Torque：10N・m（1.0kgf・m）

PY

Flywheel side

＜ For Cub with self starter
motor ＞
With electric starter models

With electric starter models◇ Tighten the sealing washer andthe hexagon bolt(arrow)on theright side of the cylinder head.
Note: Be sure that you protect
specified torque.
Hex bolt

Torque：9N・m（0.9kgf・m）＜ For Cub with self starter
motor ＞

Set the protrusion at theanti-rotation stopper◇ Insert a 0.05mm thickness gauge
between the adjust screw of the◇ Pour a small amount of engine
rocker arm and the valve stem
oil into the bolt hole next
end to insert the adjust screw.
to the shift pedal shaft(thatTighten the adjust nut so thatremoved earlier), and install
the thickness gauge can be pulled
the bolt with sealing washer.
out with a little resistance.
Note: Be sure that you protect（use 0.07 and 0.03 thickness
specified torque.
gauges and adjust so that 0.07
does not enter the gap and 0.03
Hex bolt
enters loosely, it will be
Torque：10N・m（1.0kgf・m）
about 0.05 mm.）
Adjust to 0.05 mm for both IN
and EX.

◇ Check if the valve clearance
has changed.
If it has changed, readjust it
and repeat this process until
it matches.

◇ Install three bolts to hold aleft side crankcase cover.

◇ Install two tappet caps.

Note: Be sure that you protect
specified torque.
Tappet cap

Note: Be sure that you protect
specified torque.
Bolt

Torque：10N・m（1.0kgf・m）

Torque：12N・m（1.2kgf・m）

Valve clearance(Intake side)◇ Attach the change pedal.
Note: Be sure that you protect
specified torque.
Change pedal

Torque：10N・m（1.0kgf・m）

Valve clearance(Exhaust side)

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

＜ For Cub with self starter
motor ＞◇ Attach a nut on the reverse sideof the muffler loosely for now.

◇ Remove the timing hole cap
and crankshaft hole cap.

Note: Be sure that you protect
specified torque.
Nut

Torque：10N・m（1.0kgf・m）◇ Fully tighten the loosely
tightened nuts and bolts atthree portions.

◇ In the case of vehicle withframe Nos AB27-. install thehose of the storage tank.

Note: Be sure that you protect
specified torque.
EX pipe nut

Torque：10N・m（1.0kgf・m）
BracketTorque：36N・m（3.5kgf・m）

The timing hole cap◇ Attach fuel and air hoses.
Crankshaft hole cap

Fuel hoseCO● Installation of spark plug ◇ At this point, loosely install◇ Install the plug with a plug
wrench.

a hex bolt which holds theexhaust system.

Note: Be sure that you protect
specified torque.
Plug

Note: Be sure that you protect
specified torque.
Hex bolt

Torque：11N・m（1.1kgf・m）● Installation of stock
carburetor＜ Monkey ＞
Torque：27N・m（2.7kgf・m） ◇ In the case of vehicle withframe Nos Z50J-, check that an
O-ring is attached to the inlet
pipe.
Air hose◇ Attach a plug cap to the plug.

◇ Turn on the fuel cock.

● Installation of stock
exhaust system◇ Fully tighten the loosely
tightened nuts and bolts atthree portions.

＜ Monkey ＞＜ Cub ＞◇ In installing the exhaustsystem, route the tail pipe
inside the rear shock absorberfirst, and then run the flange
close to the exhaust outletof the cylinder head.

◇ Fit the exhaust system between
the brake pedal and step andset the flange under the exhaust
port of cylinder head.
◇ Set the exhaust pipe gasket
into the space between thecylinder head and exhasut system.
Insert the spacer collar andexhaust bracket into the swing
arm pivot bolt. Install washer /flange nut.
（Fasten it only finger tight for
now at this point.）

PY◇ Attach two bolts which holdthe cylinder head and intake
manifold.

Note: Be sure that you protect
specified torque.
Bolt

Torque：10N・m（1.0kgf・m）＜ Cub ＞
◇ Make sure the O-ring isinstalled on the inlet pipe.

◇ Install a bolt on the aircleaner bracket, fastening thebolt and earth jointly at thesame time.See the figure below）◇ Install two flange collars,squeezing the exhaust pipe.

Note: Be sure that you protect
specified torque.
Bolt

Torque：10N・m（1.0kgf・m）◇ Tighten two nuts on the exhaust
pipe loosely for now.

◇ Bundle the choke cable andmain harness.
Choke cable◇ Tighten two nuts on the exhaust
pipe loosely for now.
Note: Be sure that you protect
specified torque.
Nut

Main harness

Torque：10N・m（1.0kgf・m）
Air cleaner bracket
Earth◇ Tighten the nuts to hold theflange and vehicle.

Frame

Bolt

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

◇ Attach the air cleaner to theframe with 2 bolts(left andright).

◇ Attach the breather hose(for chasiss No. AA01) to thestorage tank.

Note: Be sure that you protect
specified torque.
Bolt

Torque：10N・m（1.0kgf・m）

CO◇ Install the duct.

◇ Fit the backside of the leg
shield on the frame and thenthe front side.
＜ Monkey ＞
・Attachand tighten the plate /◇ Fasten two hex bolts on thewasher / M8 cap nut to the A.
reverse side of the front fender.
・Tighten the M6 long bolt /Note: Be sure that you protect
large diameter washer on thespecified torque.
B with the space collar on
Hex bolt
the back of the leg shield.
Torque：10N・m（1.0kgf・m）
・Attach and tighten M6 bolts /washers or hooks to C.
・Do the same on the other side.

● Installation of exterior
parts, etc.

Note: Be sure that you protect
specified torque.

A：20N・m（2.0kgf・m）
B、C：10N・m（1.0kgf・m）
C◇ Pump the tire.
注意：必ず規定空気圧を守る事。

空気圧：100kPa(1kg/cm2)
A＜ Cub ＞◇ For Little Cub, attach thehook of the skid plate to thestep bar and set it with thespace collar.

B◇ Fasten two bolts of theintake manifold.

Note: Be sure that you protect
specified torque.
Bolt

Torque：10N・m（1.0kgf・m）◇ Connect two wires of the
carburetor heater(if equipped).

A◇ Connect the horn wiring.

◇ IInstall the fuel cock with
two screws.

◇ Turn on the fuel cock.
◇ Attach the vent hose into theframe.

PY
Step bar

Skid plate hook partB

◇ The leg shield is easy toinstall with insert it from theside of the vehicle.

C◇ Check for slack in the bolts
and the like fixed all the way
from the engine to thesuspension.

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