Operation Manual
47MS 650, MS 660
English / USA
If engine is down on power, difficult to 
start or runs poorly at idling speed, first 
check the spark plug.
: Remove spark plug – see "Starting / 
Stopping the Engine".
: Clean dirty spark plug.
: Check electrode gap (A) and 
readjust if necessary – see 
"Specifications".
: Use only resistor type spark plugs 
of the approved range.
Rectify problems which have caused 
fouling of spark plug: 
: Too much oil in fuel mix.
: Dirty air filter.
: Unfavorable running conditions, 
e.g. operating at part load.
Fit a new spark plug after approx. 
100 operating hours 
or earlier if the electrodes are badly 
eroded.
To reduce the risk of fire and burn 
injury, use only spark plugs 
authorized by STIHL. Always press 
spark plug boot (2) snugly onto 
spark plug terminal (1) of the proper 
size. (Note: If terminal has 
detachable SAE adapter nut, it must 
be attached.) 
A loose connection between spark 
plug boot and ignition wire 
connector in the boot may create 
arcing that could ignite combustible 
fumes and cause a fire.
: Remove the screws (1).
: Push the hand guard up.
: Pull underside of fan housing away 
from crankcase and remove it 
downward. 
: Use screwdriver or suitable pliers to 
carefully remove spring clip (2) from 
the starter post. 
: Carefully remove the rope rotor 
with washer (3) and pawls (4). Take 
care not to pull the rewind spring 
(behind the rotor) out of the housing 
during this process.
0
00BA036 TR
1
Replacing Starter Rope 
and Rewind Spring
1
1
1
1
133BA014 KN
4
4
3
2
001BA096 KN










