CAMSHAFT, ROCKER ARMS AND VALVES

ENG

CHECKING THE VALVES AND VALVE SPRINGS

1.Measure:

Stem-to-guide clearance

Stem-to-guide clearance = valve guide inside diameter a – valve stem diameter b

Out of specification Replace the valve guide.

Clearance (stem to guide): Intake:

0.010 ~ 0.037 mm

(0.0004 ~ 0.0015 in)

<Limit>: 0.080 mm (0.0031 in) Exhaust:

0.030 ~ 0.057 mm

(0.0012 ~ 0.0022 in)

<Limit>: 0.100 mm (0.0039 in)

2.Replace:

Valve guide

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Replacement steps:

NOTE:

To ease guide removal, installation and to maintain correct fit, heat the cylinder head to 100 °C (212 °F) in an oven.

Remove the valve guide using a valve guide remover 1.

Install the new valve guide using a valve guide remover 1 and valve guide installer 2.

After installing the valve guide, bore the valve guide using a valve guide reamer 3 to obtain proper stem-to-guide clearance.

Valve guide remover (7.0 mm):

P/N. YM-01225-A, 90890-01225

Valve guide installer (7.0 mm):

P/N. YM-04017, 90890-04017

Valve guide reamer (7.0 mm):

P/N. YM-01227, 90890-01227

NOTE:

After replacing the valve guide reface the valve seat.

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Yamaha LIT-11616-16-02, 5TE-F8197-10 service manual Checking the Valves and Valve Springs, Replacement steps