CAMSHAFT

Removing the cylinder head cover

* Yamaha bond No. 1215 (Three bond No. 1215®)

Order

Job/Parts to remove

Q’ty

Remarks

 

Seat

 

Refer to GENERAL CHASSIS.

 

Side cover (left/right)

 

Refer to GENERAL CHASSIS.

 

Shroud (left/right)

 

Refer to GENERAL CHASSIS.

 

Fuel tank

 

Refer to FUEL TANK.

 

Spark plug cap

 

Disconnect.

Refer to THROTTLE BODY.

1

Cylinder head breather hose

1

 

2

Spark plug

1

 

3

Cylinder head cover

1

 

4

Timing chain guide (top side)

1

 

5

Cylinder head cover gasket

1

 

Removing the camshaft

Order

Job/Parts to remove

Q’ty

Remarks

1

Timing mark accessing screw

1

 

2

Crankshaft end accessing screw

1

 

3

Timing chain tensioner cap bolt

1

 

4

Timing chain tensioner

1

 

5

Camshaft cap

2

 

6

Clip

2

 

7

Intake camshaft

1

 

8

Exhaust camshaft

1

 

REMOVING THE CAMSHAFT

1.Remove:

  • Timing mark accessing screw “1”

  • Crankshaft end accessing screw “2”

2.Align:

  • Alignment mark

a.Turn the crankshaft counterclockwise with a wrench.

b.Align the top dead center (TDC) mark “a” on the generator rotor with the alignment mark “b” on the crankcase cover.

Align the alignment mark “c” on the exhaust camshaft sprocket and the alignment mark “d” on the intake camshaft sprocket with the edge of the cylinder head.

3.Remove:

  • Timing chain tensioner cap bolt “1”

  • Timing chain tensioner “2”

  • Gasket

4.Remove:

  • Bolt (camshaft cap) “1”

  • Camshaft cap “2”

  • Clip “3”

  • Remove the bolts (camshaft cap) in a crisscross pattern, working from the outside in.

  • In order to prevent the clip from falling into the crankcase, remove the camshaft cap.

The bolts (camshaft cap) must be removed evenly to prevent damage to the cylinder head, camshafts or camshaft caps.

5.Remove:

  • Exhaust camshaft “1”

  • Intake camshaft “2”

Attach a wire “3” to the timing chain to prevent it from falling into the crankcase.

CHECKING THE CAMSHAFT

1.Check:

  • Camshaft lobe

    Blue discoloration/pitting/scratches → Replace the camshaft.

2.Measure:

  • Camshaft lobe dimensions “A”

    Out of specification → Replace the camshaft.

Camshaft lobe dimensions

  • Lobe height limit (Intake)

    32.130 mm (1.2650 in)

  • Lobe height limit (Exhaust)

    33.460 mm (1.3173 in)

3.Measure:

  • Camshaft-journal-to-camshaft-cap clearance

    Out of specification → Measure the camshaft journal diameter.

  • Camshaft-journal-to-camshaft-cap clearance

    0.028–0.062 mm (0.0011–0.0024 in)

a.Install the camshaft into the cylinder head.

b.Position a strip of Plastigauge®“1” onto the camshaft journal as shown.

c.Install the dowel pins and the camshaft caps.

  • Tighten the camshaft cap bolts in a crisscross pattern from innermost to outer caps.

  • Do not turn the camshaft when measuring the camshaft journal-to-camshaft cap clearance.

  • Camshaft cap bolt

    10 N·m (1.0 kgf·m, 7.4 lb·ft)

d.Remove the camshaft caps and then measure the width of the Plastigauge®“1”.

4.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

    21.959–21.972 mm (0.8645–0.8650 in)

CHECKING THE TIMING CHAIN AND CAMSHAFT SPROCKET

1.Check:

  • Timing chain “1”

    Damage/stiffness → Replace the timing chain and camshaft as a set.

2.Check:

  • Camshaft sprocket

    More than 1/4 tooth wear “a”→ Replace the camshaft and the timing chain as a set.

a.

1/4 tooth

b.

Correct

1.

Timing chain roller

2.

Camshaft sprocket

CHECKING THE TIMING CHAIN TENSIONERS

1.Check:

  • Timing chain tensioner

    Crack/damage → Replace.

a.While pressing the tensioner rod lightly with your fingers, use a thin screwdriver “1” to wind the tensioner rod up fully clockwise.

b.When releasing the screwdriver by pressing lightly with your fingers, make sure that the tensioner rod will come out smoothly.

c.If not, replace the tensioner assembly.

CHECKING THE DECOMPRESSION SYSTEM

1.Check:

  • Decompression system

a.Check that the decompressor cam “1” moves smoothly.

b.Check that the decompressor lever pin “2” projects from the camshaft.

INSTALLING THE CAMSHAFTS

1.Install:

  • Exhaust camshaft “1”

  • Intake camshaft “2”

a.Turn the crankshaft counterclockwise with a wrench.

  • Apply molybdenum disulfide oil to the camshafts.

  • Apply the engine oil on the decompression system.

  • Fill the cylinder head with engine oil up to the tops “a” of the valve lifters.

b.Align the top dead center (TDC) mark “a” on the generator rotor with the alignment mark “b” on the crankcase cover.

c.Fit the timing chain “3” onto both camshaft sprockets and install the camshafts on the cylinder head.

Make sure that the alignment mark “c” on the exhaust camshaft sprocket and the alignment mark “d” on the intake camshaft sprocket are aligned with the edge of the cylinder head.

Do not turn the crankshaft during the camshaft installation. Damage or improper valve timing will result.

d.Install the clips, the camshaft caps and the bolts (camshaft cap).

  • Bolt (camshaft cap)

    10 N·m (1.0 kgf·m, 7.4 lb·ft)

  • Before installing the clips, cover the cylinder head with a clean cloth to prevent the clips from coming off into the cylinder head cavity.

  • Apply the engine oil to the threads and contact surfaces.

  • Tighten the bolts to the specified torque in two or three steps in the proper tightening sequence as shown.

The bolts (camshaft cap) must be tightened evenly, or damage to the cylinder head, camshaft caps, and camshaft will result.

2.Install:

  • Timing chain tensioner

a.While pressing the tensioner rod lightly with your fingers, use a thin screwdriver to wind the tensioner rod up fully clockwise.

b.With the tensioner rod fully wound and the chain tensioner “UP” mark “a” facing upward, install the gasket “1”, the timing chain tensioner “2” and tighten the bolts “3”.

  • Bolt (timing chain tensioner)

    10 N·m (1.0 kgf·m, 7.4 lb·ft)

c.Release the screwdriver, check that the tensioner rod comes out smoothly, and tighten the gasket “4” and the cap bolt “5”.

  • Timing chain tensioner cap bolt

    6 N·m (0.6 kgf·m, 4.4 lb·ft)

3.Turn:

  • Crankshaft

    Counterclockwise several turns.

4.Check:

  • Top dead center (TDC) mark on the generator rotor

    Align with the crankcase alignment mark.

  • Camshaft match marks

    Align with the cylinder head surface.

    Out of alignment → Adjust.

5.Install:

  • Timing chain guide (top side) “1”

  • Cylinder head cover gasket “2”

  • Cylinder head cover “3”

  • Bolt (cylinder head cover) “4”

  • Bolt (cylinder head cover)

    10 N·m (1.0 kgf·m, 7.4 lb·ft)

Before installation, apply the sealant to the cylinder head cover gasket.

  • Yamaha bond No. 1215

    90890-85505

  • Three bond No. 1215®

6.Install:

  • Cylinder head breather hose

  • Spark plug

  • Spark plug

    13 N·m (1.3 kgf·m, 9.6 lb·ft)