TOHATSU MFS 8B Service Manual page 68

6. Fully open throttle, crank engine until compression gauge
indication stabilizes, and then measure compression
pressure.
Compression Pressure (Reference) : 500 r/min
: 0.88 MPa (128 psi) [0.9 kgf/cm
Compression pressure varies depending on the
cranking speed, and normally changes at least
as much as approximately 10%.
7. If compression pressure is below specified value or varies
much among cylinders, put small amount of engine oil into
cylinders, and perform the test again.
· If compression pressure increases after the
above measure, check pistons and piston
rings for wear. Replace if necessary.
· If compression pressure does not increase
after the above measure, check valve
clearances, valves, valve seats, cylinder
sleeves, cylinder head gaskets and cylinder
head. Adjust or replace if necessary.
Perform inspection and adjustment of valve
clearances when engine is cold.
1. Disconnect starter lock cable (upper), and then recoil
starter and belt cover.
2. Remove fuel pump
3. Disconnect plug caps, then remove all spark plugs and
cylinder head cover
When removing or installing cylinder head
cover, use 10mm ring wrench with large offset
angle.
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4st 8/9.8 2016