Condition
Cause
Remedy
Engine stops while
idling
Carburetor is iced up. ► Allow saw to warm up to +10°C.
Poor acceleration
The chain is over-ten‐
sioned.
► Tension chain properly.
Chain lubrication sys‐
tem is supplying
insufficient chain oil.
► Increase oil feed rate.
Engine does not
reach maximum
RPM.
Saw is not correctly
tuned to ambient con‐
ditions.
► Calibrate the saw.
Saw chain does not
rotate when throttle is
opened.
The chain brake is
engaged.
► Disengage the chain brake.
The chain is over-ten‐
sioned.
► Tension chain properly.
Bar nose sprocket is
blocked.
► Clean the bar nose sprocket with STIHL resin solvent.
Smoke or burning
smell while cutting.
Chain is not properly
sharpened.
► Sharpen the chain properly.
Insufficient chain oil
in the tank.
► Fill up with chain oil.
Chain lubrication sys‐
tem is supplying
insufficient chain oil.
► Increase oil feed rate.
The chain is over-ten‐
sioned.
► Tension chain properly.
Chainsaw is not
being used properly.
► Have correct use explained, then practice.
18.2
Clearing the Combustion
Chamber
► Engage the chain brake.
2
1
0000-GXX-A379-A0
► Remove the filter cover (1).
► Pull off the spark plug boot (2).
► Unscrew the spark plug.
► Dry the spark plug.
WARNING
■ Unconfined sparks may occur if the starter grip
is pulled after the spark plug boot has been
removed. Sparks may cause a fire or an
explosion in an easily combustible or explo‐
sive environment. This can result in serious or
fatal injuries and damage to property.
► Move the Master Control lever to position
and hold it there before pulling the starter
grip.
► Move the Master Control lever to position
and hold it there.
► Pull the starter grip and guide it back several
times.
The combustion chamber is cleared.
► Insert and tighten down the spark plug.
English
18 Troubleshooting
26
0458-759-0121-D. VA0.A21.
Summary of Contents for MS 661 C-M
Page 1: ...STIHL MS 661 C M Instruction Manual 2 30...
Page 30: ...English 23 EC Declaration of Conformity 30 0458 759 0121 D VA0 A21...
Page 31: ...23 EC Declaration of Conformity English 0458 759 0121 D VA0 A21 31...
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