CFMoto ATV CF500/CF500-A. Service Manual

15. Engine Removal, Inspection & Installation

Piston Ring Free End Gap and End Gap

Before installing piston rings, use vernier caliper to

measure the free end gap of each ring, and then fit
ring into the cylinder.

Use thickness gauge to measure each ring end gap,

if any ring has an excess end gap, replace the
piston ring.

Piston ring free end gap limit:
Top ring: 8.9mm
2

ring: 9.5mm

Piston ring end gap limit:
Top Ring: 0.60mm
2

ring: 0.60mm

Tool: Vernier caliper

Thickness gauge

Piston Pin and Pin Bore

Use a bore gauge to measure the inner diameter of

piston pin bore.

Use micrometer to measure outer diameter of piston

pin.

If out of limit, replace both piston and piston pin.

Piston pin bore limit: 23.030mm

Use micrometer to measure piston pin outer

diameter at three points

Piston pin outer diameter limit: 22.980mm
Tools: Bore gauge (18-35mm)

Micrometer (0-25mm)

15-26

15. Engine Removal, Inspection & Installation

Connecting Rod/Crankshaft
Connecting rod small end I.D.

Use a dial gauge to measure the I.D. of connecting

rod small end. If the measurement exceeds the limit,
replace the connecting rod.

Connecting rod small end I.D. : 23.040mm
Tool: Dial Gauge (18-35mm)

Connecting Rod Deflection

Check the movement of the small end of the rod and

inspect the wear of the small end. This method is
also applicable to check and inspection of big end.

Connecting Rod Deflection: 3.0mm
Tools: Dial Gauge

Magnetic stand
V-block

Connecting Rod Big End Side Clearance

Push the big end to one side, and use thickness

gauge to measure the other side clearance.

If out of limit, replace with a new crankshaft.

Connecting Rod big end side clearance: 1.0mm
Tool: Thickness Gauge

Crankshaft Run-out

Support crankshaft with “V” blocks as illustrated. Put

the dial gauge, slowly turn the crankshaft and
measure run-out with a dial gauge.

If the run-out exceeds the limit, correct or replace

the crankshaft.

Run out limit: 0.08mm
Tools: dial gauge

Magnetic stand
V-block

15-27

15. Engine Removal, Inspection & Installation

Clutch
Clutch Shoes

Check clutch for chipping, scrape, uneven wear or

heat discoloration. At the same time check depth of
the grooves of clutch shoes. If any of the clutch
shoes has no groove, replace the clutch.

Note:

clutch should be replaced as a set.

Clutch Wheel

Check the inner clutch wheel

①

for scratches, scuffs or

blue discoloration or uneven wear. If any damage is
found, replace the clutch wheel with a new one.

Check oil seal lip for wear or damage.

Wear or Damage:

→

Replace

Use special tool to remove oil seal

Tool: Oil seal remover

Use special tool to assemble oil seal

Tool: Oil seal installer set

Check the turning of bearing.

Abnormal damage:

→

Replace

Assembly

Apply lubricant grease to oil seal when assembling.

15-28

15. Engine Removal, Inspection & Installation

Primary Sliding Sheave

Disassembly

Remove

spacer

Remove

Cam

①

and Roller

②

Roller

Check each roller and sliding face for wear and

damage.

Wear and damage:

→

Replace

Note:

rollers should be replaced as a set.

Oil Seal

Check oil seal lip for wear and damage.

Wear and damage:

→

Replace

Remove the oil seal

15-30

15. Engine Removal, Inspection & Installation

Primary Sliding Sheave and Fixed Sheave

Check the drive face for any abnormal conditions

such as damage or stepped wearing.

Damage or wearing:

→

Replace

Install oil seal with special tool.

Tool: Bearing install set

Tool Tool

Assembly

Reverse the removal procedure of primary sliding and
fixed sheave for installation.

Pay attention to the following:

Apply grease to inner bore and oil seal lip.

Note:

Wipe off any excessive grease thoroughly.

Take care not to attach any lubricant grease

to contact surface of drive belt.

Material: Lubricant grease

Position 8 rollers

①

on the primary sliding sheave

Install 4 dampers

②

to cam

③

Install cam to primary sliding sheave.

Notes:

When inserting the spacer, press down the cam
so that the rollers will not come out of position.

15-31

15. Engine Removal, Inspection & Installation

Install spacer

Secondary Sheave
Disassembly

Use special tool and holder to hold the secondary

sheave. Remove secondary sheave nut with special
tool.

Caution:

Do not remove the ring nut before attaching the
clutch spring compressor.

Tool: Nut Wrench
Sheave Holder

Attach special tool to the secondary sliding sheave

and compress it by turning in the tool handle.

Note:

Make sure that spring end A is inserted into slot
B of the tool handle.

Remove ring nut.

Tool: Secondary sliding sheave spring compressor

Note:

Since a high spring force applies to the
secondary sliding sheave, take special care that
the secondary sliding sheave will not come off
abruptly.

Slowly loosen tool handle and remove the special

tool.

tool

15-32

15. Engine Removal, Inspection & Installation

Remove

spring

①

Remove spring seat .

②

Remove guide pin and spacer.

Remove secondary sliding sheave

③

O-ring and Oil Seal

Check the O-ring and oil seal for wear and damage.

O-ring oil seal

Wear and Damage:

→

Replace

Remove Oil Seal

15-33

15. Engine Removal, Inspection & Installation

Install oil seal with special tool.

Tool: Bearing install set

tool tool

Secondary Sheave Spring

Use vernier caliper to check the spring free length. If

the length is shorter than the service limit, replace
with a new one.

Service Limit: 145.4mm

lubricant grease

Secondary Sliding and Fixed Sheave

Check drive face for any abnormal condition such

as stepped wear or damage.

Wear or damage:

→

Replace

Lubricant grease

Assembly

Install a new O-ring

Apply lubricant grease to O-ring, oil seal lip and

guide pin groove.

Material: lubricant grease

15-34

15. Engine Removal, Inspection & Installation

Install guide pin and spacer

①

Note:

To avoid damage to the oil seal lip during

assembly, slide the lip with a 0.1mm steel sheet
as guide.

Install spring seat. Align hole A with hole B.

Install spring and spring plate. Insert spring end into

the hole.

Compress spring with special tool.

Align the secondary sheave end with spring plate

hole.

Tool: Secondary sheave spring compressor

tool

Tighten ring nut temporarily.

tool

Remove the special tool from secondary sheave.

15-35

15. Engine Removal, Inspection & Installation

Tighten the ring nut with special tool to the specified

torque.

Ring Nut Tightening Torque: 100N·m
Tool: Ring nut wrench

Sheave Holder

Drive belt

Check belt for any greasy substance.

Check contact surface of belt for any cracks and

damage.

Check belt width with vernier caliper.

Damage, width out of range:

→

Replace

Belt width service limit: 33.5mm
Tool: vernier caliper

Caution:

If belt surface is stained with grease or oil, degrease the
belt thoroughly.

15-36

15. Engine Removal, Inspection & Installation

Transmission

No. Description

Qty

No. Description

Qty.

MAIN SHAFT. GEARSHIFT

DRIVEN GEAR, HIGH RANGE

SHIFT CAM

DRIVEN GEAR, LOW RANGE

RIGHT CRANKCASE

SPRING, SHIFT FORK

LEFT CRANKCASE

RIGHT SHIFT FORK

DRIVEN SECTOR GEAR

GUIDE BAR

SPROCKET, REVERSE GEAR

DRIVEN SHAFT

CHAIN, REVERSE GEAR

SPRING, SHIFT FORK

DRIVEN OUTPUT GEAR

LEFT SHIFT FORK

DRIVE SECTOR GEAR

18 SHIFT

FORK

ASSEMBLY

15-37

15. Engine Removal, Inspection & Installation

Inspection

Check main shaft gear and sprocket surface for any

damage or over wear.

Damage or over wear:

→

Replace

Check reverse gear chain for any damage or over

wear.

Damage or over wear:

→

Replace

Disassemble driven shaft as illustrated.

Check each gear surface for any damage or over

wear.

Check bearing and collar for any wear or damage..

Damage or over wear:

→

Replace

15-38

15. Engine Removal, Inspection & Installation

Check the shift fork clearance with a thickness

gauge in the groove of its gear.

Clearance exceeds the limit:

→

Replace

Shift fork to Groove clearance
Standard clearance :0.10-0.30mm
Service Limit :0. 50mm

Measure shift fork groove width with vernier caliper

Standard shift fork groove width: 6.05-6.15mm

Measure shift fork thickness with vernier calipers;

Standard fork thickness: 5.08-5.90mm

Check shift fork and for damage

①

②

or bend

Damage, bend:

→

Replace

Install shift fork to guide bar and move left and right.

In case of any unsmooth moving, replace with a new
one.

15-39

15. Engine Removal, Inspection & Installation

Put the guide bar on a flat plate and roll it. In case of

any bend, replace with a new one.

NOTE

:DON NOT attempt to correct a bent guide bar.

Check shift fork spring for breakage, damage

Broken or damaged:

→

Replace

Check shift cam groove for scratches, damage.

Scratch or damage:

→

Replace

Assembly

Reverse the removal procedure for assembly. Pay
attention to the following:

Use new retainers. Pay attention to the direction of

the retainers. Fit to the side where the thrust is as
illustrated.

Coat the gears and shafts with engine oil before

assembly.

Note:

Do not reuse the retainers

Do not expand of the gap end of new retainers too

wide when assembling.

Make sure that all the retainers are properly fitted.

15-40

15. Engine Removal, Inspection & Installation

When assembling the guide bar, take care not to

assemble the two shift forks and springs in the
opposite direction.

1. Guide bar             2. Retainer
3. Left shift fork           4. Shift fork Spring (small)
5. Right shift fork         6. shift fork spring (big)
7. Spring seat

OIL PUMP

Disassembly oil pump as illustrated:

1. Oil pump housing 2.Dowel pin
3.Oil pump shaft 4.Straight pin
5.Inner rotor, oil pump 6.Outer rotor, oil pump
7. Oil pump cover

Check oil pump housing and cover for cracks and

damage.

Crack or damage:

→

Replace

Measure top clearance “a” between inner and outer

rotors and side clearance “b” between outer rotor
and oil pump housing. If the clearance exceeds the
limit, replace with new one.

Top Clearance:0. 03-0.10mm
Service Limit: 0. 15mm

Side clearance: 0. 03-0.10mm
Service Limit: 0.12mm

15-41

CFMoto ATV CF500/CF500-A. Service Manual - part 12