Yamaha E40J - Compression Pressure

6F65G11
9-4
9
8
7
6
5
4
3
2
1
Power unit
Compression pressure
9 Consult this chart after the ignition and fuel systems have been checked.
Measure the compression
pressure.
No
Add a small amount of engine oil
into the cylinder through the
spark plug hole.
Check the piston, piston rings,
and cylinder bore for wear or
damage. Correct or replace if
worn or damaged.
Check the cylinder head gasket
and cylinder head for wear or
damage.
Replace if worn or damaged.
Does the
pressure exceed
the specification
values?
Yes
Check other component again.
Does the
compression
pressure
increase?
Yes
No
NOTE:
While restoring a damaged part, it is also necessary to trace and solve the cause of the damage.