Yamaha Grizzly YF70GG, YF70GPG, YF70GPSG. Service manual (2016)

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WATER PUMP

EBS30217

TIP

DISASSEMBLING THE WATER PUMP

Install the oil seal with a socket that matches its

1. Remove:

• Mechanical seal “1”

outside diameter.

TIP

Installed depth of oil seal “a”

Remove the mechanical seal from the inside of

0 mm (0 in)

the AC magneto cover.

New

2. Remove:

2. Install:

• Bearing “1”

• Mechanical seal “1”

New

• Oil seal “2”

ECB02410

NOTICE

TIP

Never lubricate the mechanical seal surface

Remove the bearing and oil seal from the inside

with oil or grease.

of the AC magneto cover.

TIP

Use the special tools and a press to press the

mechanical seal straight in until its flange “a”

touches the AC magneto cover.

Mechanical seal installer

90890-01581

Mechanical seal installer

YM-01581

Middle driven shaft bearing driv-

EBS30218

CHECKING THE WATER PUMP

90890-04058

Middle drive bearing installer 40

1. Check:

& 50 mm

• Water pump housing cover

YM-04058

• AC magneto cover

• Impeller

• Impeller shaft

• Water pump outlet pipe

• Water pump outlet hose

Cracks/damage/wear → Replace.

1 New

2. Check:

• Bearing

Rough movement → Replace.

EBS30219

ASSEMBLING THE WATER PUMP

1. Install:

A. Push down

• Bearing “1”

2. Mechanical seal installer

• Oil seal “2”

New

3. Middle driven shaft bearing driver

(into the AC magneto cover)

6-12

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WATER PUMP

3. Install:

• Water pump outlet hose “2” (onto the water

• Impeller “1”

jacket joint)

• Water jacket joint “3”

Impeller

TIP

10 Nm (1.0 m·kgf, 7.2 ft·lbf)

Tighten the clamp screw of each clamp “1” until

4 slots remain in the area “a” of the clamp as

TIP

shown in the illustration.

After installation, check that the impeller shaft ro-

tates smoothly.

Water jacket joint bolt

10 Nm (1.0 m·kgf, 7.2 ft·lbf)

4. Install:

• AC magneto cover

Refer to “AC MAGNETO AND STARTER

Upward

CLUTCH” on page 5-35.

EBS30569

INSTALLING THE WATER PUMP HOUSING

1. Install:

• Water pump inlet hose “1”

• Clamps “2”

• Cooling water hose joint “3”

TIP

Tighten the clamp screw of each clamp “2” until

9 slots are visible in the area “a” of the clamp as

shown in the illustration. Position the screw head

of each clamp within the range shown in the il-

lustration.

45˚

b. Upward

EBS30471

INSTALLING THE WATER JACKET JOINT

1. Install:

• Clamps “1” (onto the water pump outlet hose)

6-13

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FUEL SYSTEM

FUEL TANK

7-1

REMOVING THE FUEL TANK

7-2

REMOVING THE FUEL PUMP

7-2

CHECKING THE FUEL PUMP BODY

7-2

CHECKING THE FUEL TANK BREATHER HOSE JOINT

7-2

INSTALLING THE FUEL PUMP

7-2

INSTALLING THE FUEL TANK

7-3

THROTTLE BODY

7-4

REMOVING THE THROTTLE BODY ASSEMBLY

7-6

CHECKING THE INJECTOR

7-6

CHECKING THE THROTTLE BODY

7-6

INSTALLING THE THROTTLE BODY ASSEMBLY

7-6

CHECKING THE FUEL PRESSURE

7-7

ADJUSTING THE THROTTLE POSITION SENSOR

7-7

AIR INDUCTION SYSTEM

7-9

CHECKING THE AIR INDUCTION SYSTEM

7-13

INSTALLING THE AIR INDUCTION SYSTEM

7-13

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FUEL TANK

EBS20054

FUEL TANK

Removing the fuel tank

7 Nm (0.7 m•kgf, 5.1 ft•Ibf)

(6)

7 Nm (0.7 m•kgf, 5.1 ft•Ibf)

New

7 Nm (0.7 m•kgf, 5.1 ft•Ibf)

Order

Job/Parts to remove

Q’ty

Remarks

Refer to “GENERAL CHASSIS (1)” on page

Seat/Side panels

4-1.

Refer to “GENERAL CHASSIS (3)” on page

Rear fender

4-8.

Fuel tank breather hose

Fuel tank breather hose joint

Fuel tank shield

Fuel pump coupler

Disconnect.

Fuel hose connector holder

Fuel hose

Fuel tank

Fuel pump assembly

Damper

7-1

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FUEL TANK

EBS30221

REMOVING THE FUEL TANK

1. Extract the fuel in the fuel tank through the

fuel tank cap with a pump.

2. Remove:

• Fuel hose connector holder

• Fuel hose

EWB03050

WARNING

Cover fuel hose connections with a cloth

when disconnecting them. Residual pres-

3. Remove:

sure in the fuel lines could cause fuel to

• Fuel tank

spurt out when removing the hose.

ECB01700

TIP

NOTICE

Do not set the fuel tank down on the installation

• Be sure to disconnect the fuel hose by

surface of the fuel pump. Be sure to lean the fuel

hand. Do not forcefully disconnect the

tank in an upright position.

hose with tools.

• Although the fuel has been removed from

EBS30222

REMOVING THE FUEL PUMP

the fuel tank, be careful when removing the

1. Remove:

fuel hose, since there may be fuel remain-

• Fuel pump bracket

ing in it.

• Fuel pump

TIP

• Fuel pump gasket

ECB01450

• When removing the fuel hose from the fuel

NOTICE

pump, remove the fuel hose connector holder

• Do not drop the fuel pump or give it a

first, and next, insert a slotted head screwdriver

strong shock.

etc. in the slot part “a” of the fuel hose connec-

• Do not touch the base section of the fuel

tor cover “1”, then slide it in the direction of the

sender.

arrow, and remove the fuel hose.

• To remove the fuel hose from the throttle body,

EBS30223

slide the fuel hose connector cover “2” on the

CHECKING THE FUEL PUMP BODY

end of the hose in direction of the arrow shown,

1. Check:

press the two buttons “3” on the sides of the

• Fuel pump body

connector, and then remove the hose.

Obstruction → Clean.

• Before removing the hose, place a few rags in

Cracks/damage → Replace the fuel pump

the area under where it will be removed.

assembly.

EBS30224

CHECKING THE FUEL TANK BREATHER

HOSE JOINT

1. Check:

• Fuel tank breather hose joint

Damage/faulty → Replace.

EBS30225

INSTALLING THE FUEL PUMP

1. Install:

• Fuel pump gasket

New

• Fuel pump

• Fuel pump bracket

Fuel pump nut

7 Nm (0.7 m·kgf, 5.1 ft·lbf)

7-2

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FUEL TANK

ECB02010

TIP

NOTICE

• Do not damage the installation surfaces of the

When installing the fuel hose, make sure that

fuel tank when installing the fuel pump.

it is securely connected, and that the fuel

• Always use a new fuel pump gasket.

hose holder is in the correct position, other-

• Install the fuel pump in the direction shown in

wise the fuel hose will not be properly in-

the illustration.

stalled.

• Install the fuel pump bracket by aligning the

projections “a” on the fuel pump with the pro-

TIP

jections on the fuel tank.

• Install the fuel hose connector holder “1” se-

• Tighten the fuel pump nuts in the proper tight-

curely onto the fuel pump until a distinct “click”

ening sequence as shown.

is heard, and then make sure that it does not

come loose.

• To install the fuel hose onto the throttle body,

slide the fuel hose connector cover “2” on the

end of the hose in direction of the arrow shown.

EBS30226

INSTALLING THE FUEL TANK

1. Install:

• Damper “1”

TIP

• Fit the projections “a” on the damper into the

1st and 2nd holes on the right side of the

frame.

• Make sure that the shorter end of the damper

is facing outward as shown in the illustration.

2. Install:

• Fuel hose

• Fuel hose connector holder “1”

• Fuel pump coupler

7-3

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THROTTLE BODY

EBS20056

THROTTLE BODY

Removing the throttle body

0.8 Nm (0.08 m•kgf, 0.58 ft•Ibf)

New

2.0 Nm (0.20 m•kgf, 1.4 ft•Ibf)

3.0 Nm (0.30 m•kgf, 2.2 ft•Ibf)

2.8 Nm (0.28 m•kgf, 2.0 ft•Ibf)

Order

Job/Parts to remove

Q’ty

Remarks

Refer to “GENERAL CHASSIS (1)” on page

Seat/Side panels

4-1.

Storage compartment/Air filter case/Air filter

Refer to “GENERAL CHASSIS (5)” on page

case joint

4-17.

Intake air pressure sensor coupler

Disconnect.

Throttle position sensor coupler

Disconnect.

ISC (Idle Speed Control) unit coupler

Disconnect.

Fuel hose

Disconnect.

Throttle cable housing cover

Throttle cable

Disconnect.

Fuel injector coupler

Disconnect.

Throttle body joint clamp screw

Loosen.

Throttle body assembly

Throttle body breather hose

Throttle body joint

7-4

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THROTTLE BODY

EBS30229

2. Check:

REMOVING THE THROTTLE BODY

• Fuel passages

ASSEMBLY

Obstructions → Clean.

1. Disconnect:

▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼

• Fuel hose

a. Wash the throttle body in a petroleum- based

EWB03050

solvent.

WARNING

Do not use any caustic carburetor cleaning

Cover fuel hose connections with a cloth

solution.

when disconnecting them. Residual pres-

b. Blow out all of the passages with compressed

sure in the fuel lines could cause fuel to

air.

spurt out when removing the hose.

▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲

ECB02360

EBS30233

NOTICE

INSTALLING THE THROTTLE BODY

• Be sure to disconnect the fuel hose by

ASSEMBLY

hand. Do not forcefully disconnect the

1. Install:

hose with tools.

• Throttle body joint “1”

• Although the fuel has been removed from

TIP

the fuel tank, be careful when disconnect-

Fit the ribs “a” on the throttle body joint between

ing the fuel hose, since there may be fuel

the projections “b” on the cylinder head.

remaining in it.

TIP

• To disconnect the fuel hose from the throttle

body, slide the fuel hose connector cover “1”

on the end of the hose in direction of the arrow

shown, press the two buttons “2” on the sides

of the connector, and then disconnect the

hose.

• Before disconnecting the hose, place a few

rags in the area under where it will be discon-

nected.

2. Install:

• Throttle body assembly “1”

TIP

Fit the rib “a” on the throttle body assembly with

the projections “b” on the throttle body joint.

EBS30230

CHECKING THE INJECTOR

1. Check:

• Injector

Damage → Replace.

3. Connect:

EBS30231

• Fuel hose

CHECKING THE THROTTLE BODY

1. Check:

• Throttle body

Cracks/damage → Replace the throttle body.

7-6

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THROTTLE BODY

ECB02370

d. Connect the pressure gauge “3” and adapter

NOTICE

“4” to the fuel pump and fuel hose.

When connecting the fuel hose, make sure

that it is securely connected, and that the

Pressure gauge

90890-03153

fuel hose connector cover is in the correct

Pressure gauge

position, otherwise the fuel hose will not be

YU-03153

properly connected.

Fuel pressure adapter

TIP

90890-03176

Fuel pressure adapter

To connect the fuel hose onto the throttle body,

YM-03176

slide the fuel hose connector cover “1” on the

end of the hose in direction of the arrow shown.

e. Start the engine.

EBS30409

f. Measure the fuel pressure.

CHECKING THE FUEL PRESSURE

Out of specification → Replace the fuel

1. Check:

pump.

• Fuel pressure

▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼

Fuel pressure

a. Remove the rear fender.

324 kPa (3.24 kgf/cm², 46.1 psi)

Refer to “GENERAL CHASSIS (3)” on page

4-8.

▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲

b. Remove the fuel hose connector holder.

EBS30234

c. Disconnect the fuel hose “1” from the fuel

ADJUSTING THE THROTTLE POSITION

pump.

SENSOR

EWB03070

TIP

WARNING

• When removing the fuel hose from the fuel

• Handle the throttle position sensor with

pump, remove the fuel hose connector holder

special care.

first, and next, insert a slotted head screwdriver

• Never subject the throttle position sensor

etc. in the slot part “a” of the fuel hose connec-

to strong shocks. If the throttle position

tor cover “2”, then slide it in the direction of the

sensor is dropped, replace it.

arrow, and remove the fuel hose.

• Before removing the hose, place a few rags in

1. Check:

the area under where it will be removed.

• Throttle position sensor

Refer to “CHECKING THE THROTTLE PO-

SITION SENSOR” on page 9-96.

2. Adjust:

• Throttle position sensor angle

▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼

a. Connect the test harness- TPS (3P) “1” to

the throttle position sensor and wire harness

as shown.

b. Connect the digital circuit tester to the test

harness- TPS (3P).

7-7

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THROTTLE BODY

• Positive tester probe

yellow (wire harness color)

• Negative tester probe

black/blue (wire harness color)

Test harness- TPS (3P)

90890-03204

Test harness- TPS (3P)

YU-03204

Digital circuit tester

90890-03174

Model 88 Multimeter with ta-

chometer

YU-A1927

Turn the main switch to “

” (on).

Measure the throttle position sensor voltage.

Adjust the throttle position sensor angle so

that the voltage is within the specified range.

Throttle position sensor output

voltage

0.63-0.73 V (yellow-black/blue)

After adjusting the throttle position sensor an-

gle, tighten the throttle position sensor

screws “2” to specification.

Throttle position sensor screw

3.5 Nm (0.35 m·kgf, 2.5 ft·lbf)

▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲

7-8

-------------------------------------------------------------------------------------------------------------------------------------------------------------

AIR INDUCTION SYSTEM

EBS30235

2. Check:

CHECKING THE AIR INDUCTION SYSTEM

• Reed valve

• Reed valve stopper

Air injection

• Reed valve seat

The air induction system burns unburned ex-

Cracks/damage → Replace the reed valve

haust gases by injecting fresh air (secondary air)

assembly.

into the exhaust port, reducing the emission of

3. Check:

hydrocarbons. When there is negative pressure

• Air cut-off valve

at the exhaust port, the reed valve opens, allow-

Cracks/damage → Replace.

ing secondary air to flow into the exhaust port.

4. Check:

The required temperature for burning the un-

• Air induction system solenoid

burned exhaust gases is approximately 600 to

Refer to “CHECKING THE AIR INDUCTION

700 °C (1112 to 1292 °F).

SYSTEM SOLENOID” on page 9-96.

Air cut-off valve

EBS30236

The air cut-off valve is controlled by the signals

INSTALLING THE AIR INDUCTION SYSTEM

from the ECU in accordance with the combus-

1. Install:

tion conditions. Ordinarily, the air cut-off valve

• Reed valve plate “1”

opens to allow the air to flow during idle and

TIP

closes to cut-off the flow when the vehicle is be-

Align the notch “a” in the reed valve plate with

ing driven. However, if the coolant temperature

the projection “b” of the reed valve seat on the

is below the specified value, the air cut-off valve

cylinder head.

remains open and allows the air to flow into the

exhaust pipe until the temperature becomes

higher than the specified value.

A. From the air filter case

B. To the reed valve

1. Check:

• Hoses

Loose connections → Connect properly.

Cracks/damage → Replace.

7-13

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DRIVE TRAIN

TROUBLESHOOTING

8-1

CHECKING NOISES

8-2

TROUBLESHOOTING CHART

8-3

FRONT CONSTANT VELOCITY SHAFT ASSEMBLIES,

DIFFERENTIAL ASSEMBLY AND FRONT DRIVE SHAFT

8-4

DISASSEMBLING THE FRONT CONSTANT VELOCITY SHAFT

ASSEMBLIES

8-9

CHECKING THE FRONT CONSTANT VELOCITY SHAFT

ASSEMBLIES

8-9

ASSEMBLING THE FRONT CONSTANT VELOCITY SHAFT

ASSEMBLIES

8-10

REMOVING THE DIFFERENTIAL GEAR ASSEMBLY

8-11

CHECKING THE DIFFERENTIAL ASSEMBLY

8-11

CHECKING THE DIFFERENTIAL MOTOR OPERATION

8-11

ASSEMBLING THE DIFFERENTIAL ASSEMBLY

8-12

MEASURING THE DIFFERENTIAL GEAR BACKLASH

8-13

ADJUSTING THE DIFFERENTIAL GEAR BACKLASH

8-13

REAR CONSTANT VELOCITY SHAFT ASSEMBLIES,

FINAL DRIVE ASSEMBLY AND REAR DRIVE SHAFT

8-15

DISASSEMBLING THE REAR CONSTANT VELOCITY SHAFT

ASSEMBLIES

8-21

CHECKING THE REAR CONSTANT VELOCITY SHAFT

ASSEMBLIES

8-22

ASSEMBLING THE REAR CONSTANT VELOCITY SHAFT

ASSEMBLIES

8-22

DISASSEMBLING THE FINAL DRIVE PINION GEAR ASSEMBLY

8-23

CHECKING THE REAR DRIVE SHAFT

8-24

CHECKING THE FINAL DRIVE ASSEMBLY

8-24

ASSEMBLING THE FINAL DRIVE CASE

8-24

ASSEMBLING THE FINAL DRIVE PINION GEAR ASSEMBLY

8-24

SELECTING THE FINAL DRIVE PINION GEAR SHIM(S)

8-25

SELECTING THE FINAL DRIVEN PINION GEAR SHIM

(FINAL DRIVE CASE SIDE) AND THRUST WASHER

8-26

SELECTING THE FINAL DRIVEN PINION GEAR SHIM

(FINAL DRIVE CASE COVER SIDE)

8-27

SELECTING THE WHEEL GEAR SHIM(S)

8-28

MEASURING THE FINAL GEAR BACKLASH

8-29

ADJUSTING THE FINAL GEAR BACKLASH

8-29

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TROUBLESHOOTING

EBS20058

TROUBLESHOOTING

The following conditions may indicate damaged shaft drive components:

Symptoms

Possible Causes

1. A pronounced hesitation or “jerky” movement

A. Bearing damage.

during acceleration, deceleration, or sustained

B. Improper gear backlash.

speed. (This must not be confused with engine

C. Gear tooth damage.

surging or transmission characteristics.)

D. Broken drive shaft.

2. A “rolling rumble” noticeable at low speed; a high-

E. Broken gear teeth.

pitched whine; a “clunk” from a shaft drive com-

F. Seizure due to lack of lubrication.

ponent or area.

G. Small foreign objects lodged between the moving

3. A locked-up condition of the shaft drive train

parts.

mechanism, no power transmitted from the en-

gine to the front and/or rear wheels.

TIP

Areas A, B, and C above may be extremely difficult to diagnose. The symptoms are quite subtle and

difficult to distinguish from normal vehicle operating noise. If there is reason to believe these compo-

nents are damaged, remove the components and check them.

8-1

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TROUBLESHOOTING

EBS30237

b. Apply a leak-localizing compound or dry pow-

CHECKING NOISES

der spray to the shaft drive.

1. Investigate any unusual noises.

c. Road test the vehicle for the distance neces-

sary to locate the leak.

▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼

Leakage → Check the component housing,

The following “noises” may indicate a me-

chanical defect:

gasket, and/or seal for damage.

Damage → Replace the component.

a. A “rolling rumble” noise during coasting, ac-

celeration, or deceleration. The noise in-

TIP

creases with front and/or rear wheel speed,

• An apparent oil leak on a new or nearly new ve-

but it does not increase with higher engine or

hicle may be the result of a rust-preventative

transmission speeds.

coating or excessive seal lubrication.

Diagnosis: Possible wheel bearing damage.

• Always clean the vehicle and recheck the sus-

Refer to “TROUBLESHOOTING CHART” on

pected location of an apparent leakage.

page 8-3.

▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲

b. A “whining” noise that varies with accelera-

tion and deceleration.

Diagnosis: Possible incorrect reassembly,

too little gear backlash.

Refer to “TROUBLESHOOTING CHART” on

page 8-3.

EWB02900

WARNING

Insufficient gear backlash is extremely de-

structive to the gear teeth. If a test ride, fol-

lowing reassembly, indicates these

symptoms, stop riding immediately to mini-

mize gear damage.

c. A slight “thunk” evident at low speed opera-

tion. This noise must be distinguished from

normal vehicle operation.

Diagnosis: Possible broken gear teeth.

EWB02910

WARNING

Stop riding immediately if broken gear teeth

are suspected. This condition could result in

the shaft drive assembly locking up, causing

a loss of control and possible injury to the

rider.

▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲

2. Check:

• Drained oil

Drained oil shows large amounts of metal

particles → Check the bearing for seizure.

TIP

A small amount of metal particles in the oil is nor-

mal.

3. Check:

• Oil leakage

▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼

a. Clean the entire vehicle thoroughly, then dry

it.

8-2

-------------------------------------------------------------------------------------------------------------------------------------------------------------

TROUBLESHOOTING

EBS30238

TROUBLESHOOTING CHART

When basic conditions (a) and (b) exist, check the following points:

YES →

Replace the wheel bearing. (Refer to “TIE-

Elevate and spin both wheels. Feel

RODS AND STEERING KNUCKLES” on

for wheel bearing damage.

page 4-61 and “REAR KNUCKLES AND

STABILIZER” on page 4-70.)

NO ↓

NO →

Torque to specification. (Refer to “FRONT

Check the wheel nuts and axle nuts

WHEELS” on page 4-20 and “REAR

for tightness.

WHEELS” on page 4-23.)

YES ↓

NO →

Constant velocity shaft bearings and differ-

Check the front constant velocity

ential bearings are probably not damaged.

shaft assemblies. Feel for bearing

Repeat the test or remove the individual

damage.

components.

YES ↓

NO →

Adjust per instructions. (Refer to “AD-

Check the rear brake adjustment.

JUSTING THE REAR DISC BRAKE” on

page 3-12.)

YES ↓

NO →

Constant velocity shaft bearings and final

Check the rear constant velocity

gear bearings are probably not damaged.

shaft assemblies. Feel for bearing

Repeat the test or remove the individual

damage.

components.

YES ↓

Remove the shaft drive components.

8-3

Yamaha Grizzly YF70GG, YF70GPG, YF70GPSG. Service manual (2016) - part 16