
20
CARBURETOR
ADJUSTMENT
Engine Break-In
New engines must be operated a minimum duration of two tanks of fuel
break-in before carburetor adjustments can be made. During the break-
in period your engine performance will increase and exhaust emissions
will stabilize. Idle speed can be adjusted as required.
High Altitude Operation
This engine has been factory adjusted to maintain satisfactory starting,
emission, and durability performance up to 1,100 feet above sea level
(ASL) (96.0 kPa). To maintain proper engine operation and emission
compliance above 1,100 feet ASL the carburetor may need to be
adjusted by an authorized ECHO service dealer.
IMPORTANT
If the engine is adjusted for operation
above
1,100 feet ASL, the
carburetor must be re-adjusted when operating the engine
below
1,100 feet ASL, otherwise severe engine damage can result.
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
compliance with California Emission Regulations.
In addition, the carburetor is equipped with “H” (High Speed
Needle) and “L” (Low Speed Needle) needle adjustment limiters that
prevent settings outside acceptable limits.
1.
Before adjusting carburetor clean or replace air filter and muffler,
“Spark Arrestor Screen”.
2.
Start engine and run several minutes to bring to operating
temperature. Flash choke twice during warm-up to clear any air
from the fuel system.
3.
Stop engine. Turn “H” speed needle CCW (Counterclock-wise) to
stop. Turn “L” speed needle midway between full CW (Clockwise)
stop and CCW stop.
4.
Idle Speed Adjustment
•Before adjusting blower, install all blower pipes. Start engine, turn
“idle” speed adjustment screw either CW or CCW until the tip just
contacts the throttle plate. Then turn (2) two additional turns CW
for initial setting. Blower should operate with an even idle at low r/
min.
5.
Accelerate to full throttle for 2 - 3 seconds to clear any excess fuel
in the engine, then return to idle. Accelerate engine to full throttle
to check for smooth transition from idle to high speed. If engine
hesitates turn “L” needle CCW 1 /8 turn and repeat acceleration.
Continue adjustment until smooth acceleration results.
6.
Check idle speed and reset if necessary as described in item 4.
High speed needle (H)
Low speed needle (L)
Idle adjustment needle