28
CARBURETOR
ADJUSTMENT
SRM-2100SB 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 and LO needle adjust-
ment limiters that prevent settings outside acceptable limits.
1. Before adjusting the carburetor, clean or replace the air filter and
spark arrester screen.
2. Trimmer line must be extended to the cut-off knife.
3. Start engine and run for several minutes to reach operating tempera-
ture.
4. Stop engine. Turn HI speed needle (C) CCW (counter clockwise) to
stop. Turn LO speed needle (B) midway between full CCW and CW
(clockwise) stops.
5. Idle Speed Adjustment.
• Start engine and turn “idle” speed adjustment screw (A) CW
until the cutting attachment begins to turn, then turn the screw
CCW until cutting attachment stops turning. Turn screw CCW
an additional 1/4 turn.
6. 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 needle (B) CCW an additional 1/8 turn and repeat acceleration.
Continue adjusting until smooth acceleration results.
7. Check HI speed RPM at W.O.T. (Wide Open Throttle). HI speed
RPM should be set to specifications found on page 13 "Specifica-
tions" of this manual.
8. Check idle speed and reset if necessary. If a tachometer is available,
idle speed should be set to the specification found on page 13
"Specifications" of this manual.
WARNING DANGER
When carburetor adjustment is completed, the cutting attachment
should not turn at idle, otherwise serious personal injury may result.
A
B
C
A
SRM-2100SB
