Carburetor Adjustment Emission - Echo SRM-3400 Operator's Manual

26
CARBURETOR ADJUSTMENT
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 emission regulations. In addition, the carburetor is
equipped with HI and LO 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. Trimmer line must be extended to the cut-off knife.
3. Start engine and run for several minutes to reach operating
temperature.
4. Stop engine. Turn HI speed needle (A) 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 (C) CW
until the cutting attachment begins to turn, then turn the screw
CCW until attachment stops turning. Turn screw (C) 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 accelera-
tion. 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 the specifications found on Page 12
"Specifications" of this manual for the type of cutting attachment
on this unit.
8. Check idle speed and reset if necessary. If a tachometer is avail-
able, idle speed should be set to the specifications found on page
12 "Specifications" of this manual.
WARNING
When carburetor adjustment is completed, the cutting attachment
should not turn at idle, otherwise serious personal injury may
result.
DANGER