Yamaha F6BMH User Manual

CAMSHAFT AND VALVES
REMOVING THE VALVE
Remove:
 Valve spring lock 1
 Valve spring retainer 2
 Valve spring 3
 Valve spring seat 4
 Intake valve or exhaust valve 5
NOTE:
 Set the attachment on to the center of the
spring retainer.
 Do not overtighten the valve spring
compressor.
CHECKING THE VALVE AND VALVE
GUIDE
1. Measure:
 Valve guide inside diameter
a
Out of specification  Replace.
2. Measure:
 Valve seat width
b
Out of specification  Replace.
3. Measure:
 Valve margin thickness
c
Out of specification  Replace.
Valve spring compressor:
YM-01253/90890-04019
Attachment:
YM-04018/90890-04018
Valve guide inside diameter
a
(intake guide and exhaust guide):
5.500 - 5.512 mm
( 0.2165 - 0.2170 in)
Valve seat width
b
(intake valve and exhaust valve):
0.6 - 0.8 mm (0.023 - 0.031 in)
Valve margin thickness
c
(intake valve and exhaust valve):
0.7 mm (0.027 in)
5-45

Yamaha F6BMH Specifications

General

Max Output	6 hp
Starting System	Manual
Gear Ratio	2.08:1
Fuel Induction System	Carburetor
Ignition System	CDI
Lubrication	Wet Sump
Oil Injection	No
Engine Type	4-Stroke, SOHC
Weight	27 kg
Prop Shaft Horsepower	6 hp
Full Throttle RPM Range	5, 000 - 6, 000 rpm
Shaft Length	15 in
Steering	Tiller
Full Throttle Operating Range	5, 000 - 6, 000 rpm