
3-12
ENGINE
5. Inspect:
• Air filter element
Damage→Replace.
6. Apply:
• Foam-air-filter oil or equivalent oil 
to the element
• Squeeze out the excess oil. Ele-
ment should be wet but not drip-
ping.
• Wipe off the oil left on the element 
surface using a clean dry cloth. (Ex-
cess oil in the element may ad-
versely affect engine starting.)
7. Install:
• Air filter guide "1"
• Align the projection "a" on filter 
guide with the hole "b" in air filter el-
ement.
• Apply the lithium soap base grease 
on the matching surface "c" on air 
filter element.
8. Install:
• Air filter element "1"
Align the projection "a" on filter guide 
with the hole "b" in air filter case.
9. Hook:
•Binder "1"
Hook the binder "1" so that it contacts 
the filter guide projections "a".
CHECKING THE ENGINE OIL 
LEVEL
1. Stand the machine on a level sur-
face.
• When checking the oil level make 
sure that the machine is upright.
• Place the machine on a suitable 
stand.
Never remove the oil tank cap just 
after high speed operation. The 
heated oil could spurt out. causing 
danger. Wait until the oil cools 
down to approximately 70°C 
(158°F).
2. Idle the engine more than 3 min-
utes while keeping the machine 
upright. Then stop the engine and 
inspect the oil level.
3. Remove:
• Oil tank cap 1
4. Inspect:
• Oil level
Check that the engine oil is above 
the level mark "a" and that the oil 
does not come out when the 
check bolt "1" is removed.
Below the level mark "a"→Add oil 
through the filler cap hole until it is 
above the level mark "a".
Oil comes out at the check bolt→
Drain the oil until it stops coming 
out.
When inspecting the oil level, do not 
screw the oil level gauge into the oil 
tank. Insert the gauge lightly.
(For CDN)
• Do not add any chemical addi-
tives. Engine oil also lubricates 
the clutch and additives could 
cause clutch slippage.
• Do not allow foreign material to 
enter the crankcase.
(Except for CDN)
Recommended oil:
Yamalube 4, 
SAE10W30 or 
SAE20W40
Yamalube 4-R, 
SAE10W50
API service SG type or 
higher, JASO standard 
MA
Recommended oil:
SAE10W30, 
SAE10W40, 
SAE15W40, SAE20W40 
or SAE20W50
API service SG type or 
higher, JASO standard 
MA 

3-13
ENGINE
• Do not add any chemical addi-
tives or use oils with a grade of 
CD "a" or higher.
• Do not use oils labeled "ENERGY 
CONSERVING II" "b" or higher. 
Engine oil also lubricates the 
clutch and additives could cause 
clutch slippage.
• Do not allow foreign material to 
enter the crankcase.
5. Start the engine and let it warm up 
for several minutes.
When the oil tank is empty, never 
start the engine.
6. Idle the engine more than 10 sec-
onds while keeping the machine 
upright. Then stop the engine and 
add the oil to the maximum level.
7. Install:
• Oil tank cap
CHANGING THE ENGINE OIL
1. Start the engine and let it warm up 
for several minutes.
2. Stop the engine and place an oil 
pan under the drain bolt.
3. Remove:
• Engine guard "1"
• Oil tank plug "2"
• Oil filler cap "3"
• Drain bolt (with gasket) "4"
• Oil filter drain bolt (O-ring) "5"
• Drain bolt (with gasket) "6"
Drain the crankcase and oil tank 
of its oil.4. If the oil filter is to be replaced dur-
ing this oil change, remove the fol-
lowing parts and reinstall them.
Replacement steps:
a. Remove the oil filter element cov-
er "1" and oil filter element "2".
b. Check the O-rings "3", if cracked 
or damaged, replace them with a 
new one.
c. Install the oil filter element and oil 
filter element cover.
5. Install:
• Gaskets  
• Oil filter drain bolt
• Drain bolt (right crankcase)
• Drain bolt (left crankcase)
6. Fill:
• Engine oil7. Install:
• Oil filler cap "1"
8. Inspect:
• Engine (for oil leaks)
• Oil level
Refer to "CHECKING THE EN-
GINE OIL LEVEL".
CHECKING THE OIL PRESSURE
1. Check:
• Oil pressure
Checking steps:
a. Slightly loosen the oil pressure 
check bolt "1".
b. Start the engine and keep it idling 
until oil starts to seep from the oil 
pressure check bolt. If no oil 
comes out after one minute, turn 
the engine off so it will not seize.
c. Check oil passages and oil pump 
for damage or leakage.
d. Start the engine after solving the 
problem(s) and recheck the oil 
pressure.
e. Tighten the oil pressure check 
bolt.
Oil filter element cover:
10 Nm (1.0 m•kg, 7.2 
ft•lb)
Oil filter drain bolt:
10 Nm (1.0 m•kg, 7.2 
ft•lb)
Drain bolt (right crank-
case):
20 Nm (2.0 m•kg, 14 
ft•lb)
Drain bolt (left crank-
case):
20 Nm (2.0 m•kg, 14 
ft•lb)
Oil quantity:
Periodic oil change:
0.95 L (0.84 Imp qt, 
1.00 US qt)
With oil filter replace-
ment:
1.0 L (0.88 Imp qt, 1.06 
US qt)
Total amount:
1.2 L (1.06 Imp qt, 1.27 
US qt)
Oil pressure check bolt:
10 Nm (1.0 m•kg, 7.2 
ft•lb) 

5-34
OIL FILTER ELEMENT AND WATER PUMP
OIL FILTER ELEMENT AND WATER PUMP
REMOVING THE OIL FILTER ELEMENT AND WATER PUMP
Order Part name Q'ty Remarks
Right engine guard  Refer to "ENGINE REMOVAL" section.
Drain the engine oil. Refer to "CHANGING THE ENGINE OIL" 
section in the CHAPTER 3.
Drain the coolant. Refer to "CHANGING THE COOLANT" sec-
tion.
Exhaust pipe Refer to "EXHAUST PIPE AND SILENCER" 
section.
Brake pedal  Refer to "ENGINE REMOVAL" section.
Clutch cover Refer to "CLUTCH" section.
1 Oil filter element cover 1
2 Oil filter element 1
3 Coolant pipe 2 1
4 Water pump housing 1
5Pin 2
6 Oil tank breather hose 1
7 Kickstarter crank 1
8 Right crankcase cover 1
10 Nm (1.0 m   kg, 7.2 ft   lb)
10 Nm (1.0 m   kg, 7.2 ft   lb)
10 Nm (1.0 m   kg, 7.2 ft   lb)
10 Nm (1.0 m   kg, 7.2 ft   lb)
10 Nm (1.0 m   kg, 7.2 ft   lb)
33 Nm (3.3 m   kg, 24 ft   lb)
14 Nm (1.4 m   kg, 10 ft   lb)
12 Nm (1.2 m   kg, 8.7 ft   lb) 

5-35
OIL FILTER ELEMENT AND WATER PUMP
9 Gasket 1
10 Dowel pin/O-ring 3/1
11 Impeller 1 Refer to removal section.
12 Washer 1 Refer to removal section.
13 Impeller shaft 1 Refer to removal section.
14 Oil seal 1 1 Refer to removal section.
15 Oil seal 2 1 Refer to removal section.
16 Bearing 1 Refer to removal section. Order Part name Q'ty Remarks
10 Nm (1.0 m   kg, 7.2 ft   lb)
10 Nm (1.0 m   kg, 7.2 ft   lb)
10 Nm (1.0 m   kg, 7.2 ft   lb)
10 Nm (1.0 m   kg, 7.2 ft   lb)
10 Nm (1.0 m   kg, 7.2 ft   lb)
33 Nm (3.3 m   kg, 24 ft   lb)
14 Nm (1.4 m   kg, 10 ft   lb)
12 Nm (1.2 m   kg, 8.7 ft   lb) 

5-36
OIL FILTER ELEMENT AND WATER PUMP
REMOVING THE IMPELLER 
SHAFT
1. Remove:
• Impeller "1"
• Washer "2"
• Impeller shaft "3"
Hold the impeller shaft on its width 
across the flats "a" with spanners, 
etc. and remove the impeller.
REMOVING THE OIL SEAL
It is not necessary to disassemble the 
water pump, unless there is an abnor-
mality such as excessive change in 
coolant level, discoloration of coolant, 
or milky transmission oil.
1. Remove:
• Bearing "1"
• Oil seal "2"
CHECKING THE IMPELLER SHAFT
1. Inspect:
• Impeller shaft "1"
Bend/wear/damage→Replace.
Fur deposits→Clean.CHECKING THE BEARING
1. Inspect:
•Bearing
Rotate inner race with a finger.
Rough spot/seizure→Replace.
CHECKING THE OIL SEAL
1. Inspect:
• Oil seal "1"
Wear/damage→Replace.
INSTALLING THE OIL SEAL
1. Install:
• Oil seal "1" 
• Apply the lithium soap base grease 
on the oil seal lip.
• Install the oil seal with its manufac-
ture's marks or numbers facing the 
right crankcase cover "2".
2. Install:
•Bearing "1"
Install the bearing by pressing its out-
er race parallel.
INSTALLING THE IMPELLER 
SHAFT
1. Install:
• Impeller shaft "1"
• Washer "2"
• Impeller "3"
• Take care so that the oil seal lip is 
not damaged or the spring does not 
slip off its position.
• When installing the impeller shaft, 
apply the engine oil on the oil seal 
lip, bearing and impeller shaft. And 
install the shaft while turning it.
• Hold the impeller shaft on its width 
across the flats "a" with spanners, 
etc. and install the impeller.
INSTALLING THE RIGHT 
CRANKCASE COVER
1. Install:
• Dowel pin "1"
• O-ring "2" 
•Collar "3"
• Gasket "4" 
Apply the lithium soap base grease 
on the O-ring.
Impeller:
14 Nm (1.4 m•kg, 10 
ft•lb) 

5-37
OIL FILTER ELEMENT AND WATER PUMP
2. Install:
• Right crankcase cover "1"
•Bolt "2"
•Bolt
• Apply the engine oil on the impeller 
shaft end.
• When installing the crankcase cov-
er onto the crankcase, be sure that 
the impeller shaft end "2" aligns 
with the balancer end slot "3".
• Tighten the bolts in stage, using a 
crisscross pattern.
INSTALLING THE KICKSTARTER 
CRANK
1. Install:
• Kickstarter crank "1"
• Washer
• Bolt (kickstarter crank) 
Install so that there is a clearance "a" 
of 8 mm (0.31 in) or more between 
the kickstarter and frame and that the 
kickstarter does not contact the 
crankcase cover when it is pulled.
2. Install:
• Oil tank breather hose "1"
•Clamp "2"
INSTALLING THE WATER PUMP 
HOUSING
1. Install:
• Dowel pin "1"
• O-ring "2" 
Apply the lithium soap base grease 
on the O-ring.
2. Install:
• Water pump housing "1"
• Bolt (water pump housing) "2"
• Washer "3" 
• Coolant drain bolt "4"3. Install:
• O-ring "3" 
• Coolant pipe "1"
• Bolt (coolant pipe) "2"
Apply the lithium soap base grease 
on the O-ring.
INSTALLING THE OIL FILTER 
ELEMENT
1. Install:
• Oil filter element "1"
• O-ring "2" 
• Oil filter element cover "3"
• Bolt (oil filter element cover)
Apply the lithium soap base grease 
on the O-ring.
Bolt:
12 Nm (1.2 m•kg, 8.7 
ft•lb)
Bolt:
10 Nm (1.0 m•kg, 7.2 
ft•lb)
Bolt (kickstarter crank):
33 Nm (3.3 m•kg, 24 
ft•lb)Clamp:
2 Nm (0.2 m•kg, 1.4 
ft•lb)
Bolt (water pump hous-
ing):
10 Nm (1.0 m•kg, 7.2 
ft•lb)
Coolant drain bolt:
10 Nm (1.0 m•kg, 7.2 
ft•lb)
Bolt (coolant pipe):
10 Nm (1.0 m•kg, 7.2 
ft•lb)
Bolt (oil filter element 
cover):
10 Nm (1.0 m•kg, 7.2 
ft•lb) 

5-38
BALANCER
BALANCER
REMOVING THE BALANCER
Order Part name Q'ty Remarks
Primary driven gear  Refer to "CLUTCH" section.
Right crankcase cover Refer to "OIL FILTER ELEMENT AND WA-
TER PUMP" section.
Stator  Refer to "CDI MAGNETO" section.
1 Nut (balancer) 1 Refer to removal section.
2 Nut (primary drive gear) 1 Refer to removal section.
3 Nut (balancer shaft driven gear) 1 Refer to removal section.
4 Lock washer 1
5 Balancer 1
6 Straight key 1
7 Conical washer 1
8 Primary drive gear 1
9 Balancer shaft drive gear 1
10 Lock washer 1
11 Balancer shaft driven gear 1 

5-40
OIL PUMP
OIL PUMP
REMOVING THE OIL PUMP
Order Part name Q'ty Remarks
Primary driven gear Refer to "CLUTCH" section.
Right crankcase coverRefer to "OIL FILTER ELEMENT AND WA-
TER PUMP" section.
1 Circlip 1
2 Washer 1
3 Oil pump drive gear 1
4 Oil pump assembly 1
5 Dowel pin 2
6 Outer rotor 2 1
7 Circlip 1
8 Inner rotor 2 1
9 Dowel pin 1
10 Oil pump cover 1
11 Outer rotor 1 1
12 Inner rotor 1 1
13 Dowel pin 1
14 Washer 1