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

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ENGINE REMOVAL (1)

EBS30127

INSTALLING THE EXHAUST PIPE AND

MUFFLER

1. Install:

• Gasket “1”

New

• Exhaust pipe “2”

• Exhaust pipe nuts “3”

Exhaust pipe nut

20 Nm (2.0 m·kgf, 14 ft·lbf)

New

2. Install:

• Muffler bracket “4”

• Muffler bracket bolts “5”

Muffler bracket bolt

20 Nm (2.0 m·kgf, 14 ft·lbf)

3. Install:

• Gasket “6”

New

• Muffler “7”

• Washer “8”

• Muffler bolt “9”

EBS30554

INSTALLING THE V-BELT COOLING DUCTS

TIP

1. Install:

Do not fully tighten the muffler bolt.

• V-belt cooling intake duct joint “1”

4. Install:

• V-belt cooling intake duct “2”

• Springs “10”

▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼

a. Position the V-belt cooling intake duct joint

TIP

with its arrow mark “a” pointing toward the en-

Install the springs so that the spring ends are

gine.

pointing inward as shown in the illustration.

b. Align the projection on the V-belt cooling in-

take duct joint with the rib on the crankcase in

the area “b” shown in the illustration.

c. Align the screw head with the seam on the V-

belt cooling intake duct joint in the area “c”

shown in the illustration.

d. Align the projection on the V-belt cooling in-

take duct with the projection on the V-belt

cooling intake duct joint in the area “d” shown

in the illustration.

e. Align the bend in the screw clamp with the

5. Tighten:

projection on the V-belt cooling intake duct

• Muffler bolt “9”

joint in the area “e” shown in the illustration.

Muffler bolt

33 Nm (3.3 m·kgf, 24 ft·lbf)

5-4

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ENGINE REMOVAL (1)

d,e

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2. Install:

• V-belt cooling exhaust duct joint “1”

• V-belt cooling exhaust duct “2”

▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼

a. Position the V-belt cooling exhaust duct joint

with its arrow mark “a” pointing toward the en-

gine.

b. Align the projection on the V-belt cooling ex-

haust duct joint with the projection on the

drive belt case in the area “b” shown in the il-

lustration.

c. Align the screw head with the arrow mark “a”

on the V-belt cooling exhaust duct joint in the

area “c” shown in the illustration.

d. Align the projection on the V-belt cooling ex-

haust duct with the projection on the V-belt

cooling exhaust duct joint in the area “d”

shown in the illustration.

e. Align the screw head with the rib on the V-belt

cooling exhaust duct in the area “e” shown in

the illustration.

5-5

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ENGINE REMOVAL (2)

EBS30553

INSTALLING THE DRIVE SELECT LEVER

UNIT

1. Install:

• Shift arm “1”

• Drive select lever unit “2”

• Drive select lever shift rod “3”

Shift arm bolt

14 Nm (1.4 m·kgf, 10 ft·lbf)

LOCTITE®

Drive select lever unit bolt

7 Nm (0.7 m·kgf, 5.1 ft·lbf)

Drive select lever shift rod lock-

nut (select lever unit side)

8 Nm (0.8 m·kgf, 5.8 ft·lbf)

Drive select lever shift rod lock-

nut (shift arm side)

8 Nm (0.8 m·kgf, 5.8 ft·lbf)

TIP

• Make sure that the drive select lever and trans-

mission are in “N” (neutral).

• The installed length “a” of the shift rod is 410

mm (16.1 in).

5-7

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ENGINE REMOVAL (3)

EBS20120

ENGINE REMOVAL (3)

Disconnecting the leads, cables and hoses

17 Nm (1.7 m•kgf, 12 ft•Ibf)

Order

Job/Parts to remove

Q’ty

Remarks

Refer to “GENERAL CHASSIS (4)” on page

Footrest board

4-11.

Refer to “GENERAL CHASSIS (5)” on page

Air filter case

4-17.

Refer to “AIR INDUCTION SYSTEM” on

Air cut-off valve assembly

page 7-9.

Throttle body assembly

Refer to “THROTTLE BODY” on page 7-4.

Coolant reservoir

Refer to “RADIATOR” on page 6-4.

Thermostat

Refer to “THERMOSTAT” on page 6-7.

Water pump assembly

Refer to “WATER PUMP” on page 6-10.

Refer to “FRONT CONSTANT VELOCITY

SHAFT ASSEMBLIES, DIFFERENTIAL AS-

Differential assembly

SEMBLY AND FRONT DRIVE SHAFT” on

page 8-4.

Refer to “REAR CONSTANT VELOCITY

SHAFT ASSEMBLIES, FINAL DRIVE AS-

Final drive assembly

SEMBLY AND REAR DRIVE SHAFT” on

page 8-15.

Refer to “ELECTRIC STARTER” on page

Starter motor

5-40.

5-8

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ENGINE REMOVAL (3)

Disconnecting the leads, cables and hoses

17 Nm (1.7 m•kgf, 12 ft•Ibf)

Order

Job/Parts to remove

Q’ty

Remarks

Cylinder head breather hose

Coolant temperature sensor coupler

Disconnect.

Spark plug cap

Shift control cable

Disconnect.

Reverse switch lead

Disconnect.

Speed sensor coupler

Disconnect.

Crankshaft position sensor coupler

Disconnect.

AC magneto lead coupler

Disconnect.

Gear position switch coupler

Disconnect.

Water pump drain hose

5-9

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ENGINE REMOVAL (3)

Removing the engine

42 Nm (4.2 m•kgf, 30 ft•Ibf)

10 Nm (1.0 m•kgf, 7.2 ft•Ibf)

42 Nm (4.2 m•kgf, 30 ft•Ibf)

10 Nm (1.0 m•kgf, 7.2 ft•Ibf)

42 Nm (4.2 m•kgf, 30 ft•Ibf)

Order

Job/Parts to remove

Q’ty

Remarks

Rubber damper nut (front side)

Engine mounting bolt (rear) (M6)

Engine mounting bolt (rear) (M10)

Rubber damper nut (rear side)

Rubber damper (rear side)

TIP

Engine

Remove the engine from the left side of the

vehicle.

Engine mounting bolt (front) (M6)

Engine mounting bolt (front) (M10)

Rubber damper (front side)

5-10

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ENGINE REMOVAL (3)

EBS30351

INSTALLING THE ENGINE

Engine mounting bolt (front)

1. Install:

(M10)

• Rubber dampers (front side) “1”

42 Nm (4.2 m·kgf, 30 ft·lbf)

• Engine mounting bolts (front) (M10) “2”

Engine mounting bolt (front) (M6)

• Engine mounting bolts (front) (M6) “3”

10 Nm (1.0 m·kgf, 7.2 ft·lbf)

• Engine “4”

LOCTITE®

Engine mounting bolt (rear) (M10)

• Rubber dampers (rear side) “5”

42 Nm (4.2 m·kgf, 30 ft·lbf)

• Rubber damper nuts (rear side) “6”

Engine mounting bolt (rear) (M6)

• Engine mounting bolts (rear) (M10) “7”

10 Nm (1.0 m·kgf, 7.2 ft·lbf)

• Engine mounting bolts (rear) (M6) “8”

LOCTITE®

• Rubber damper nuts (front side) “9”

Rubber damper nut (front side)

ECB01630

42 Nm (4.2 m·kgf, 30 ft·lbf)

NOTICE

Rubber damper nut (rear side)

Make sure that the engine does not strike the

42 Nm (4.2 m·kgf, 30 ft·lbf)

brake pipe when installing it.

TIP

Do not fully tighten the bolts and nuts.

2. Tighten:

• Engine mounting bolts (front) (M10) “2”

• Engine mounting bolts (front) (M6) “3”

• Engine mounting bolts (rear) (M10) “7”

• Engine mounting bolts (rear) (M6) “8”

• Rubber damper nuts (front side) “9”

• Rubber damper nuts (rear side) “6”

5-11

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CAMSHAFTS

EBS20106

CAMSHAFTS

Removing the cylinder head cover

10 Nm (1.0 m•kgf, 7.2 ft•Ibf)

11 Nm (1.1 m•kgf, 8.0 ft•Ibf)*

(4)

Specified angle 30-45˚*

New

10 Nm (1.0 m•kgf, 7.2 ft•Ibf)

New

(4)

New

* When installing a new spark plug, tighten the spark plug to 11 Nm (1.1 m·kgf, 8.0 ft·lbf).

* When reusing a spark plug, tighten the spark plug to 30°-45°.

Order

Job/Parts to remove

Q’ty

Remarks

Refer to “GENERAL CHASSIS (5)” on page

Storage compartment

4-17.

Refer to “ENGINE REMOVAL (3)” on page

Cylinder head breather hose

5-8.

Spark plug cap

Disconnect.

Spark plug

Breather plate cover

Breather plate cover gasket

Breather plate

Cylinder head cover

Cylinder head cover gasket

Timing chain guide (upper side)

5-12

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CAMSHAFTS

Removing the camshafts

10 Nm (1.0 m•kgf, 7.2 ft•Ibf)

5 Nm (0.5 m•kgf, 3.6 ft•Ibf)

(8)

New

4.0 Nm (0.40 m•kgf, 2.9 ft•Ibf)

New

11 Nm (1.1 m•kgf, 8.0 ft•Ibf)

Order

Job/Parts to remove

Q’ty

Remarks

Crankshaft end accessing screw

Timing mark accessing screw

Timing chain tensioner

Timing chain tensioner gasket

Camshaft cap

Bearing stopper

Intake camshaft

Exhaust camshaft

5-13

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CAMSHAFTS

EBS30432

REMOVING THE CAMSHAFTS

1. Remove:

• Crankshaft end accessing screw “1”

• Timing mark accessing screw “2”

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3. Remove:

• Timing chain tensioner

• Timing chain tensioner gasket

4. Remove:

2. Align:

• Camshaft cap “1”

• Mark “a” on the AC magneto rotor

• Bearing stoppers “2”

(with the mark “b” in the AC magneto cover)

ECB02430

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NOTICE

a. Turn the crankshaft counterclockwise.

• To prevent damage to the cylinder head,

camshafts or camshaft cap, loosen the

camshaft cap bolts in stages and in a criss-

cross pattern, working from the outside in.

• Be sure not to let the bearing stoppers fall

into the crankcase when removing it.

b. Position the mark “a” on the AC magneto ro-

tor with the mark “b” in the AC magneto cov-

er.

TIP

When the holes “c” in the intake camshaft

sprocket and exhaust camshaft sprocket are po-

sitioned above the cylinder head mating surface

5. Remove:

“d” as shown in the illustration, and the marks “e”

• Intake camshaft “1”

and “f” on the sprockets are aligned with the cyl-

• Exhaust camshaft “2”

inder head mating surface “d”, the piston is at

TIP

TDC.

To prevent the timing chain from coming off the

crankshaft sprocket, fasten it with a wire “3”.

5-14

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CAMSHAFTS

3. Measure:

• Camshaft-journal-to-camshaft-cap clearance

Out of specification → Measure the camshaft

journal diameter.

Camshaft-journal-to-camshaft-

cap clearance

0.037-0.075 mm (0.0015-0.0030

in)

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EBS30433

a. Install the camshafts into the cylinder head

CHECKING THE CAMSHAFTS

(without the camshaft cap).

Check:

b. Position a strip of Plastigauge® “1” onto the

• Camshaft lobes

camshaft journal as shown.

Blue discoloration/pitting/scratches → Re-

place the camshaft.

Measure:

• Camshaft lobe dimensions “a” and “b”

Out of specification → Replace the camshaft.

Camshaft lobe dimensions

Lobe height (Intake) limit

33.800 mm (1.3307 in)

Base circle diameter (Intake) limit

24.850 mm (0.9783 in)

c. Install the camshaft cap.

Lobe height (Exhaust) limit

30.750 mm (1.2106 in)

TIP

Base circle diameter (Exhaust)

• Tighten the camshaft cap bolts in the tighten-

limit

ing sequence as shown.

22.350 mm (0.8799 in)

• Do not turn the camshaft when measuring the

camshaft journal-to-camshaft cap clearance

with the Plastigauge®.

Camshaft cap bolt

10 Nm (1.0 m·kgf, 7.2 ft·lbf)

d. Remove the camshaft cap, and then mea-

sure the width of the Plastigauge® “1”.

5-15

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CAMSHAFTS

EBS30435

CHECKING THE TIMING CHAIN TENSIONER

1. Check:

• Timing chain tensioner

Cracks/damage/rough movement → Re-

place.

▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼

a. Lightly press the timing chain tensioner rod

into the timing chain tensioner housing by

hand.

TIP

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While pressing the timing chain tensioner rod,

4. Measure:

wind it clockwise with a flat-head screwdriver un-

• Camshaft journal diameter “a”

til it stops.

Out of specification → Replace the camshaft.

Within specification → Replace the cylinder

head and camshaft cap as a set.

Camshaft journal diameter

21.946-21.963 mm (0.8640-

0.8647 in)

b. Make sure that the timing chain tensioner rod

moves in and out of the timing chain tension-

er housing smoothly. If there is rough move-

ment, replace the timing chain tensioner.

EBS30434

CHECKING THE CAMSHAFT SPROCKETS

1. Check:

• Camshaft sprocket

More than 1/4 tooth wear “a” → Replace the

camshaft sprockets and timing chain as a set.

▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲

EBS30436

INSTALLING THE CAMSHAFTS

1. Align:

• Mark “a” on the AC magneto rotor

(with the mark “b” in the AC magneto cover)

▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼

a. Turn the crankshaft counterclockwise.

1/4 tooth

b. Correct

1. Timing chain

2. Camshaft sprocket

5-16

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CAMSHAFTS

3. Install:

• Bearing stoppers

• Camshaft cap “1”

Camshaft cap bolt

10 Nm (1.0 m·kgf, 7.2 ft·lbf)

ECB02450

NOTICE

• The camshaft cap bolts must be tightened

evenly or damage to the cylinder head,

b. Position the mark “a” on the AC magneto ro-

camshaft cap, and camshafts will result.

tor with the mark “b” in the AC magneto cov-

• Do not turn the crankshaft when installing

er.

the camshaft cap to avoid damage or im-

proper valve timing.

TIP

Tighten the camshaft cap bolts in the tightening

sequence as shown.

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2. Install:

• Timing chain “1”

(onto the camshaft sprockets “2”)

• Exhaust camshaft

• Intake camshaft

4. Install:

ECB02440

NOTICE

• Timing chain tensioner gasket

New

• Timing chain tensioner

Do not turn the crankshaft when installing

▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼

the timing chain to avoid damage or improp-

a. Remove the timing chain tensioner cap bolt

er valve timing.

and gasket.

TIP

b. Install a new gasket and the timing chain ten-

sioner “1” onto the cylinder.

When installing the timing chain “1”, make sure

that the holes “a” in the camshaft sprockets “2”

Timing chain tensioner bolt

are positioned above the cylinder head mating

10 Nm (1.0 m·kgf, 7.2 ft·lbf)

surface “b” as shown in the illustration, and the

marks “c” and “d” on the sprockets are aligned

TIP

with the cylinder head mating surface “b”.

Turn the timing chain tensioner rod fully clock-

wise with a flat-head screwdriver, and then, with

c d

the tensioner rod turned all the way into the tim-

ing chain tensioner housing (with the thin screw-

driver still installed), install the timing chain

tensioner “1” onto the cylinder.

5-17

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CAMSHAFTS

c. Install a new gasket and the timing chain ten-

7. Measure:

sioner cap bolt.

• Valve clearance

Out of specification → Adjust.

Timing chain tensioner cap bolt

Refer to “ADJUSTING THE VALVE CLEAR-

5 Nm (0.5 m·kgf, 3.6 ft·lbf)

ANCE” on page 3-5.

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EBS30437

INSTALLING THE BREATHER PLATE

5. Turn:

1. Install:

• Crankshaft

(several turns counterclockwise)

• Breather plate cover gaskets

New

6. Check:

• Breather plate

• Mark “a”

• Breather plate cover

Make sure the mark “a” on the AC magneto

Breather plate cover bolt

rotor is aligned with the mark “b” in the AC

10 Nm (1.0 m·kgf, 7.2 ft·lbf)

magneto cover.

• Camshaft sprocket mark “c”

TIP

Make sure the marks “c” on the camshaft

sprockets are aligned with the cylinder head

Tighten the breather plate cover bolts in the

mating surface “d”.

proper tightening sequence as shown.

Out of alignment → Adjust.

Refer to the installation steps above.

• Timing chain guide

Make sure that the timing chain guide and

timing chain are positioned correctly.

5-18

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CYLINDER HEAD, CYLINDER, AND PISTON

EBS20107

CYLINDER HEAD, CYLINDER, AND PISTON

Removing the cylinder head

1st

30 Nm (3.0 m•kgf, 22 ft•Ibf)

(4)

2nd

70 Nm (7.0 m•kgf, 51 ft•Ibf)

3rd

Loosen 360˚

New

4th

30 Nm (3.0 m•kgf, 22 ft•Ibf)

5th

Specified angle 85-90˚

6th

Specified angle 85-90˚ (again)

10 Nm (1.0 m•kgf, 7.2 ft•Ibf)

New

10 Nm (1.0 m•kgf, 7.2 ft•Ibf)

New

18 Nm (1.8 m•kgf, 13 ft•Ibf)

Order

Job/Parts to remove

Q’ty

Remarks

Drain.

Coolant

Refer to “CHANGING THE COOLANT” on

page 3-29.

Drain.

Engine oil

Refer to “CHANGING THE ENGINE OIL” on

page 3-24.

Refer to “ENGINE REMOVAL (1)” on page

Exhaust pipe

5-3.

Cylinder head cover/Intake camshaft/Exhaust

Refer to “CAMSHAFTS” on page 5-12.

camshaft

Thermostat/Coolant temperature sensor

Refer to “THERMOSTAT” on page 6-7.

Water jacket joint

Refer to “WATER PUMP” on page 6-10.

Throttle body assembly

Refer to “THROTTLE BODY” on page 7-4.

Refer to “AIR INDUCTION SYSTEM” on

Reed valve assembly

page 7-9.

5-19

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CYLINDER HEAD, CYLINDER, AND PISTON

Removing the cylinder head

1st

30 Nm (3.0 m•kgf, 22 ft•Ibf)

(4)

2nd

70 Nm (7.0 m•kgf, 51 ft•Ibf)

3rd

Loosen 360˚

New 4

4th

30 Nm (3.0 m•kgf, 22 ft•Ibf)

5th

Specified angle 85-90˚

6th

Specified angle 85-90˚ (again)

10 Nm (1.0 m•kgf, 7.2 ft•Ibf)

New

10 Nm (1.0 m•kgf, 7.2 ft•Ibf)

New

18 Nm (1.8 m•kgf, 13 ft•Ibf)

Order

Job/Parts to remove

Q’ty

Remarks

Oil hose (crankcase to cylinder)

Cylinder bolt

Cylinder head bolt

M11

Cylinder head

Cylinder head gasket

Dowel pin

5-20

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CYLINDER HEAD, CYLINDER, AND PISTON

EBS30438

• Before removing the piston pin, deburr the pis-

REMOVING THE CYLINDER HEAD

ton pin clip grooves and the piston pin bore ar-

1. Remove:

ea. If both areas are deburred and the piston

• Cylinder bolt (M6) (×2)

pin is still difficult to remove, remove it with the

• Cylinder head bolt (M6) (×2)

piston pin puller set “4”.

• Cylinder head bolt (M11) (×4)

• Remove the piston pin from the side of the pis-

• Cylinder head

ton that has the manufacturer’s mark “a”.

TIP

• Loosen the bolts in the proper sequence as

Piston pin puller set

shown.

90890-01304

• Loosen each bolt 1/2 of a turn at a time. After

Piston pin puller

all of the bolts are fully loosened, remove them.

YU-01304

• M6 × 25 mm: “1”-“4”

• M11 × 208 mm: “5”-“8”

×4

FWD

×4

Remove:

• Top ring

EBS30146

•

2nd ring

REMOVING THE PISTON

• Oil ring

1. Remove:

TIP

• Piston pin clips “1”

When removing a piston ring, open the end gap

• Piston pin “2”

with your fingers and lift the other side of the ring

• Piston “3”

over the piston crown.

ECB01380

NOTICE

Do not use a hammer to drive the piston pin

out.

TIP

• Before removing the piston pin clips, cover the

crankcase opening with a clean rag to prevent

the piston pin clips from falling into the crank-

case.

5-22

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CYLINDER HEAD, CYLINDER, AND PISTON

EBS30439

TIP

CHECKING THE CYLINDER HEAD

To ensure an even surface, rotate the cylinder

1. Eliminate:

• Combustion chamber carbon deposits

head several times.

(with a rounded scraper)

▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲

ECB01851

NOTICE

EBS30147

CHECKING THE CYLINDER AND PISTON

Do not use a sharp instrument; otherwise,

1. Check:

the following may be damaged or scratched:

• Piston wall

• Spark plug bore threads

• Cylinder wall

• Valve seats

Vertical scratches → Replace the cylinder,

2. Check:

and replace the piston and piston rings as a

• Cylinder head

set.

Damage/scratches → Replace.

2. Measure:

• Cylinder head water jacket

• Piston-to-cylinder clearance

Mineral deposits/rust → Eliminate.

▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼

3. Measure:

a. Measure the cylinder bore “C” with the cylin-

• Cylinder head warpage

der bore gauge.

Out of specification → Resurface the cylinder

TIP

head.

Measure the cylinder bore “C” by taking side-to-

side and front-to-back measurements of the cyl-

Warpage limit

inder.

0.03 mm (0.0012 in)

Bore

103.000-103.020 mm (4.0551-

4.0559 in)

Wear limit

103.080 mm (4.0583 in)

Taper limit

0.050 mm (0.0020 in)

Out of round limit

0.050 mm (0.0020 in)

“C” = maximum of D₁, D₂, D₃, D₄, D₅, D₆

▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼

a. Place a straightedge “1” and a thickness

Taper (front-to-back) = maximum difference be-

tween D₁, D₃, D₅

gauge “2” across the cylinder head.

Taper (side-to-side) = maximum difference be-

tween D₂, D₄, D₆

Out of round (top) = difference between D₁, D₂

Out of round (middle) = difference between D₃,

Out of round (bottom) = difference between D₅,

D₆

b. Measure the warpage.

c. If the limit is exceeded, resurface the cylinder

head as follows.

d. Place a 400-600 grit wet sandpaper on the

surface plate and resurface the cylinder head

using a figure-eight sanding pattern.

5-23

Yamaha Grizzly YF70GG, YF70GPG, YF70GPSG. Service manual (2016) - part 11