Carburetor Adjustment

Idle adjusting screw

Low speed needle (L)

High speed needle (H)

Engine Break-In

New engines must be operated a minimum duration of two tanks of fuel break-in before carburetor adjust- ments can be made. During the break-in period your engine performance will increase and exhaust emis- sions will stabilize. Idle speed can be adjusted as required.

High Altitude Operation

This engine has been factory adjusted to maintain sat- isfactory starting, emission, and durability performance up to 1,100 feet above sea level (ASL) (96.0 kPa). To maintain proper engine operation and emission compli- ance 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 may result.

Every unit is run at the factory and the carburetor is set in compliance with Emission Regulations. In addition, the carburetor is equipped with “H” (High Speed) and “L” (Low Speed) needle adjustment limiters that prevent settings outside acceptable limits.

1.Before adjusting carburetor clean or replace air filter and muffler “Spark Arrestor Screen”.

2.Make sure the bar and chain are properly adjusted.

3.Start engine and run several minutes to bring to oper- ating temperature. Flash choke twice during warm-up to clear any air from the fuel system.

4.Stop engine.

Turn “H” speed needle counterclockwise (CCW) to stop.

Turn “L” speed needle midway between full clockwise (CW) stop and CCW stop.

5.Idle Speed Adjustment:

•Start engine, turn “Idle” speed adjustment screw CW until the saw chain begins to turn, then turn screw out CCW until the saw chain stops turning. Turn screw out, CCW, an additional 1/4 turn.

WARNING

Cutting attachment must not move when unit is idling.

6.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.

7.Check idle speed and reset if necessary as described in item 5. If a tachometer is available idle speed should be set to 3000 r/min.

CAUTION

When starting, idling adjustment speed should be adjusted not to rotate the saw chain. Correct idle speed is adjusted 3000 r/min. Or 1/4 turn CCW from the point the chain stops moving.

When you experience trouble with the carburetor, contact your dealer.

CS-352