27
A
HS L
S-
+
H -
+
S-
+
L-
+
H
CAUTION:
Carburetor adjustment must only be done with the engine
warm, a clean air filter and the saw chain properly tensioned
and mounted. Always have a MAKITA service center do
carburetor adjustment, since incorrect adjustment can
cause considerable damage to the engine.
Due to new emissions regulations, the adjustment range of
screws (H) and (L) has been limited. This adjustment range
limitation (to about 180 degrees) prevents over-rich set-
tings. This ensures compliance with emissions regulations,
optimum engine performance and economical fuel consump-
tion.
Factory setting of adjustment screws (H) and (L):
Screwed out almost all the way (counter-clockwise).
For proper adjustment, proceed as follows:
Checking adjustment screw (H)
Before starting, make sure that adjustment screw (H) is un-
screwed all the way (until you feel a stop). Limitations do not
protect against too lean running (insufficient fuel)!
1. Start engine and let it warm up (3-5 minutes)
2. Set idle
3. Set highest permissible speed.
4. Check acceleration
5. Check idle speed
2. Set idle
Set the idle speed per the technical specifications.
Turning the adjusting screw (S) in (clockwise) increases the
idle speed. Turning it out (counter-clockwise) lowers the
idle speed. The chain or blade must not move in idle!
3. Set the top speed
Set the top speed with a minimal adjustment to screw (H)
in accordance with the technical data.
Screwing in adjustment screw (H) clockwise increases
engine speed. Never exceed the top speed under any
circumstances!
4. Check acceleration
When the throttle is pressed, the engine should go
smoothly from idle to high speed.
Unscrew adjustment screw (L) counter-clockwise in
small steps until acceleration is good.
5. Checking the idle speed
After setting the maximum permissible speed, check
the idle speed (the saw chain or cutting tool must not
turn in idle).
Repeat the adjustment procedure starting with step
2 above until idle speed, acceleration, and speed are
all good.
Adjusting the carburetor