Instruction Manual

HT 250
English
29
Exhaust emissions are controlled by the
design of the engine and components
(e.g. carburation, ignition, timing and
valve or port timing).
General Information
The carburetor comes from the factory
with a standard setting.
This setting provides an optimum fuel-air
mixture under most operating
conditions.
Preparations
N Shut off the engine.
N Check chain tension.
N Check the air filter and clean or
replace if necessary.
N Check the spark arresting screen in
the muffler and clean or replace it if
necessary.
N Check that the throttle cable is
properly adjusted – readjust if
necessary – see chapter on
"Adjusting the Throttle Cable".
Standard Setting
N Turn the high speed screw (H)
clockwise as far as stop, then turn it
back 3/4 turn.
N Turn the low speed screw (L)
clockwise as far as stop, then turn it
back 3/4 turn.
Adjusting Idle Speed
N Carry out standard setting.
N Start and warm up the engine for
about 3 minutes.
Engine stops while idling
N Turn the idle speed screw (LA)
clockwise until the chain begins to
run – then back it off 1/4 turn.
Engine Management Adjusting the Carburetor
255BA006 KN
H
L
255BA007 KN
LA