Cylinder Compression; Cylinder Head Cover/Camshaft Removal - Honda CRF150F Service Manual

CYLINDER HEADIVALVES ('03 - '05 model)
CYLINDER COMPRESSION
Warm the engine to norma l operating tempera t u re.
Stop the engine and remove the spark plug (page 3-
8).
Install the compression gauge into t he spark plug
hole.
Shift the transmission into neutral.
Push the choke lever down fully (open).
Operate the throttle all the way and crank t he
engine with the kickstarter pedal several t i mes until
the gauge reading st ops rising.
COMPRESSION PRESSURE :
1, 196 kPa (12.2 kg / cm
2
,
174 psi) at 1,000 rpm
Low compression can be caused by:
- blown cy linder head gasket
- improper valve adjust ment
- valve leakage
- worn piston ring or cylinder
High compression can be caused by:
- carbon deposits in combustion chamber or on
piston head
CYLINDER HEAD COVER/CAMSHAFT
REMOVAL
8-6
Remove the engine from the frame (page 7-2).
Remove t he spark plug (page 3-8) .
Remove the f ollowing and set t he piston posit ion to
Top Dead Center on the compression stroke (page
3-9):
- t iming hole cap
- crankshaft hole cap
- valve adjusting hole caps
Remove the following:
- two socket bolts and washers (loosen them alter-
nately)
- cam chain tensioner lifter
- gasket