Snowmobile Yamaha FX10X, FX10RTX, FX10RTRX, FX10RTRAX, FX10MTX, FX10MTRX, FX10MTRAX. Manual - part 49

5-16

ENG

CAMSHAFTS

CAMSHAFTS

Order

Job name/Part name

Q’ty

Remarks

Camshafts removal

Remove the parts in the order listed below.

Engine

Refer to “ENGINE ASSEMBLY”.

1

Timing accessing screw

1

2

Crankshaft end cover

1

3

Timing chain tensioner

1

4

Timing chain tensioner gasket

1

5

Exhaust camshaft cap

3

NOTE:

During removal, the dowel pins may still be
connected to the camshaft caps.

6

Intake camshaft cap

3

7

Dowel pin

12

8

Exhaust camshaft

1

9

Exhaust camshaft sprocket

1

10

Intake camshaft

1

11

Intake camshaft sprocket

1

For installation, reverse the removal proce-
dure.

24 Nm (2.4 m 

•

 kg, 17 ft 

•

 lb)

12 Nm (1.2 m 

•

 kg, 8.7 ft 

•

 lb)

10 Nm (1.0 m 

•

 kg, 7.2 ft 

•

 lb)

È:

É:

Ê:

New

New

M

M

New

New

5

8

5

7

9

10

6

6

11

3

4

È

É

Ê

Ê

E

2

1

LS

LS

5-17

ENG

CAMSHAFTS

REMOVAL

1. Remove:

• Timing accessing screw
• Crankshaft end cover

2. Align:

• “I” mark 

a on the AC magneto rotor

(with the stationary pointer 

b on the AC mag-

neto cover)

NOTE:

• Turn the crankshaft clockwise.
• When piston #3 is at TDC on the compression

stroke, align the “I” mark 

a on the AC magneto

rotor with the stationary pointer 

b on the AC

magneto cover.

• TDC on the compression stroke can be found

when the camshaft lobes for cylinder #3 are
turned away from each other.

b

a

EX

IN

3. Remove:

• Timing chain tensioner 1 
• Gasket

1

4. Remove:

• Camshaft caps
• Dowel pins

CAUTION:

To prevent damage to the cylinder head, cam-
shafts or camshaft caps, loosen the camshaft
cap bolts in stages and in a crisscross pattern,
working from the outside in.

5. Remove:

• Exhaust camshaft 1 

(with camshaft sprocket)

• Intake camshaft 2 

(with camshaft sprocket)

NOTE:

To prevent the timing chain from falling into the
crankcase, fasten it with a wire 3.

2

3

1

5-18

ENG

CAMSHAFTS

6. Remove:

• Exhaust camshaft sprocket 1 
• Intake camshaft sprocket 2 

(Use the special tool 3)

Rotor holding tool:

90890-01235

Universal magneto & rotor holder:

YU-01235

INSPECTION

1. Inspect:

• Camshaft lobes

Blue discoloration/pitting/scratches 

→ 

Replace the camshaft.

2. Measure:

• Camshaft lobe dimensions 

a and b 

Out of specification 

→ Replace the camshaft.

Camshaft dimensions:

Intake:
<Limit>:

a 34.250 mm (1.3484 in) 

b 24.850 mm (0.9783 in)

Exhaust:
<Limit>:

a 33.850 mm (1.3327 in)

b 24.850 mm (0.9783 in)

5-19

ENG

CAMSHAFTS

3. Measure:

• Camshaft runout

Out of specification 

→ Replace.

Camshaft runout:

0.030 mm (0.0012 in)

4. Measure:

• Camshaft-journal-to-camshaft-cap clearance

Out of specification 

→ Measure the camshaft

journal diameter.

Measurement steps:

• Install the camshaft into the cylinder head (with-

out the dowel pins and camshaft caps).

• Position a strip of Plastigauge

®

  1 onto the

camshaft journal as shown.

• Install the dowel pins and camshaft caps.

NOTE:

• Tighten the camshaft cap bolts in stages and in a

crisscross pattern, working from the inner caps
out.

• Do not turn the camshaft when measuring the

camshaft journal-to-camshaft cap clearance with
the Plastigauge

®

.

• Remove the camshaft caps and then measure

the width of the Plastigauge

®

 1.

Camshaft-journal-to-camshaft-cap 
clearance:

0.028 ~ 0.062 mm
(0.0011 ~ 0.0024 in)

T

 

R

.

.

Camshaft cap bolt:

10 Nm (1.0 m · kg, 7.2 ft · lb)

1

1

5. Measure:

• Camshaft journal diameter 

a 

Out of specification 

→ Replace the camshaft.

Within specification 

→ Replace the cylinder

head and the camshaft caps as a set.

Camshaft journal diameter:

24.459 ~ 24.472 mm
(0.9630 ~ 0.9635 in)