38
English / USA
TS 400
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.
Replacing the starter rope
: Undo the screws (1)
: Remove the starter cover (2) from 
the engine unit
00BA036 TR
1
Replacing the starter rope / 
rewind spring
338BA027
1
1
2
1