20
ADJUSTING
CARBURETOR
-
GENERAL
Level 2.
Tools required: Screwdriver, tachometer.
Parts required: none.
NOTE
Do not adjust carburetor unless necessary. If you have difficultly,
see your ECHO dealer.
Adjustment Screws
Idle Speed (A)
Control throttle opening at idle.
Low (LO) Speed (B)
Controls amount of fuel at low speed and
supplementary fuel for smooth progression from
idle to high speed.
Hi (HI) Speed (C)
Controls amount of fuel at full throttle
Before Adjustment
Check that:
-
Air filter is clean and properly installed.
-
Spark arrestor screen and exhaust port are free of carbon
-
Blower pipes are installed
Initial Adjustment
NOTE
The needle screws have a sharp point. To avoid carburetor damage,
do not use excessive force when seating needle in body.
1. Turn HI and LO adjustment screws (C) and (B) clockwise until
seated lightly in carburetor body.
2. Turn (B) adjustment screw counter clockwise 1-1/8 turn.
3. Start engine and allow it to run at high idle until warn (approx. 2-3
minutes).
NOTE
Idle speed screw may have to be readjusted to keep engine from
stalling.
Initial Adjustment
1. Slowly turn the (LO) adjustment screw (B) clockwise and note the
position when the engine speed drops.
2. Turn the (LO) adjustment screw (B) counter clockwise and note the
position when engine speed drops.
3. Set the screw midway between these points.
C
A
B
