20
CARBURETOR
ADJUSTMENT
Emission Models
Level 2.
Tools required: Screwdriver, Tachometer (ECHO P/N 99051130017).
Parts required: None.
NOTE
Every unit is run at the factory and the carburetor is set in compli-
ance with EPA Phase 1 and California Emission Regulations. In
addition, the carburetor is equipped with HI (A) and LO (B) needle
adjustment limiters that prevent settings outside acceptable limits.
1.
Before adjusting the carburetor, clean or replace the air filter and
spark arrester screen.
2.
Start engine and run for several minutes to reach operating
temperature.
3.
Stop engine. Turn HI (A) speed needle CCW (counter clockwise)
to stop. Turn LO (B) speed needle midway between full CCW and
CW (clockwise) stops.
4.
Idle Speed Adjustment.
-Start engine and turn idle (C) speed adjustment screw CW until the
tines begin to turn, then turn the screw CCW until tines stop
turning. Turn screw CCW an additional 1/4 turn.
5.
Accelerate to full throttle for 2-3 seconds to clear excess fuel from
engine then return to idle. Accelerate to full throttle to check for
smooth transition from idle to full throttle. If engine hesitates, turn
LO (B) needle CCW an additional 1/8 turn and repeat acceleration.
Continue adjusting until smooth acceleration results.
6.
Check HI (A) speed RPM at W.O.T. (Wide Open Throttle). HI
speed RPM should be set to specifications found on page 10
"Specifications" of this manual.
7.
Check idle speed and reset if necessary. If a tachometer is available,
idle speed should be set to the specification found on page 10
"Specifications" of this manual.
WARNING DANGER
When carburetor adjustment is completed, tines should not move
at idle, otherwise serious personal injury may result.
A
B
C
