Yamaha Tracer MT09TRA - Service manual > Cylinder head

Removing the cylinder head

1. Remove:

• Intake camshaft
• Exhaust camshaft

Refer to "REMOVING THE CAMSHAFTS"

2. Remove:

• Cylinder head bolt (M6) (x 4)
• Cylinder head bolt (M9) (x 8)

TIP

• Loosen the bolts in the proper sequence as shown.
• Loosen each bolt 1/2 of a turn at a time. After all of the bolts are fully loosened, remove them.

Checking the timing chain guide (exhaust side)

1. Check:

• Timing chain guide (exhaust side) Damage/wear→ Replace.

Checking the cylinder head

1. Eliminate:

• Combustion chamber carbon deposits (with a rounded scraper)

TIP

Do not use a sharp instrument to avoid damaging or scratching:

• Spark plug bore threads
• Valve seats

2. Check:

• Cylinder head

Damage/scratches → Replace.

• Cylinder head water jacket

Mineral deposits/rust → Eliminate.

3. Measure:

Cylinder head warpage Out of specification → Resurface the cylinder head.

Warpage limit 0.10 mm (0.0039 in)

a. Place a straightedge "1" and a thickness gauge "2" across the cylinder head.

Thickness gauge 90890-03180

Feeler gauge set YU-26900-9

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.

TIP

To ensure an even surface, rotate the cylinder head several times.

Installing the cylinder head

1. Install:

• Timing chain guide (exhaust side) "1"
• Cylinder head gasket "2"
• Dowel pins "3"

2. Install:

• Cylinder head
• Cylinder head bolt (M6) (x 4)
• Cylinder head bolt (M9) (x 8)

TIP

• Pass the timing chain through the timing chain cavity.
• Lubricate the cylinder head bolt (M9) thread and mating surface with engine oil.

3. Tighten:

• Cylinder head bolt "1"-"8"
• Cylinder head bolt "9"-"12"

Cylinder head bolt "1"-"8" 1st: 25 Nm (2.5 m*kgf, 18 ft*lbf) *2nd: 16 Nm (1.6 m*kgf, 12 ft*lbf) +90º

Cylinder head bolt "9"-"12" 10 Nm (1.0 m*kgf, 7.2 ft*lbf)

* Following the tightening order, loosen the bolt one by one and then retighten it to the specific torque and the specific angle.

TIP

Tighten the cylinder head bolts "1"-"8" in the tightening sequence as shown and torque them in 2 stages.

See also: