18
MS 271 C, MS 291 C
3.7
Engine
Always check and, if necessary,
repair the following parts before
looking for faults on the engine:
- Air filter
- Fuel system
- Carburetor
- Ignition system
Condition
Cause
Remedy
Engine does not start easily, stalls
at idle speed, but operates normally
at full throttle
Oil seals in engine damaged
Replace the oil seals
Engine pan leaking or
damaged (cracks)
Re-seal engine pan, replace engine
housing if necessary
Engine does not deliver full power
or runs erratically
Piston rings worn or broken
Fit new piston rings
Muffler / spark arresting screen
carbonized
Clean the muffler (inlet and
exhaust), replace spark arresting
screen, replace muffler if necessary
Air filter dirty
Clean or replace air filter
Fuel hose kinked or torn
Fit new hose or position it free from
kinks
Engine overheating
Insufficient cylinder cooling. Air
inlets in fan housing blocked or
cooling fins on cylinder very dirty
Thoroughly clean all cooling air
openings and the cylinder fins
Air inlet in fan housing dirty
Clean air inlet in fan housing
