Instruction Manual

HT 250
English
30
Saw chain runs while engine is idling
N Turn the idle speed screw (LA)
counterclockwise until the chain
stops moving and then turn the
screw about another 1/2 to 1 full
turn in the same direction.
WARNING
If the chain continues moving when the
engine is idling, have your machine
checked and repaired by your servicing
dealer.
Erratic idling behavior, poor acceleration
(even though setting of LA screw is
correct).
Idle setting is too lean
N Turn the low speed screw (L)
counterclockwise, no further than
stop, until the engine runs and
accelerates smoothly.
It is usually necessary to change the
setting of the idle speed screw (LA) after
every correction to the low speed
screw (L).
Fine Tuning for Operation at High
Altitude
A slight correction of the setting may be
necessary if the engine does not run
satisfactorily:
N Carry out standard setting.
N Warm up the engine.
N Turn high speed screw (H) slightly
clockwise (leaner) – no further than
stop.
NOTICE
After returning from high altitude, reset
the carburetor to the standard setting.
If the setting is too lean there is a risk of
engine damage due to insufficient
lubrication and overheating.
If there is a loss of engine power, the
machine is difficult to start or runs poorly
at idle, first check the spark plug.
Install a new spark plug after
approximately 100 operating hours or
earlier if the electrodes are
eroded/corroded.
The wrong fuel mix (too much engine oil
in the gasoline), a dirty air filter and
unfavorable running conditions (mostly
at part throttle etc.) affect the condition
of the spark plug. These factors cause
deposits to form on the insulator nose,
which may degrade performance.
Removing the spark plug
N Move the slide control to STOP-0.
N Pull off the spark plug boot (1).
N Unscrew the spark plug.
Spark Plug
1
249BA063 KN