Cub Cadet MTD 90 Series - Manual (Page 31)

B ASIC T ROUBLESHOOTING
25
7. Compare the results to the following chart.
Leak-down Testing Results
Symptom Possible cause
Air escaping from
the breather Worn cylinder or piston rings.
Possible blown head gasket
Air escaping from
the exhaust Leaking exhaust valve
Air escaping from
the carburetor Leaking intake valve
Gauge reading
low Cylinder and piston rings are in
good condition
Gauge reading
moderate There is some wear in the
engine, but it is still usable
Gauge reading
high excessive wear of cylinder and/
or piston rings. Engine should
be short blocked or it could be a
blown head gasket.