Echo CS-590 Operator's Manual - page 24

24

CS-590

CARBURETOR ADJUSTMENT

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

operating 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.

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 2800 r/min.

   WARNING

Cutting attachment must not move when unit

is idling.

   CAUTION

When starting, idling adjustment speed

should be adjusted not to rotate the saw

chain. Correct idle speed is adjusted 2800

r/min. Or 1/4 turn CCW from the point the

chain stops moving.

When you experience trouble with the

carburetor, contact your dealer.

Idle adjusting screw

High speed needle (H)

Low speed needle (L)

High Altitude Operation

This engine has been factory adjusted to maintain

satisfactory starting, emission, and durability

performance up to 330 m above sea level (ASL)

(96.0 kPa). To maintain proper engine operation

and emission compliance above 330 m ASL the

carburetor may need to be adjusted by an

authorized ECHO service dealer.

IMPORTANT

If the engine is adjusted for operation above 330

m ASL, the carburetor must be readjusted when

operating the engine below 330 m ASL,

otherwise severe engine damage may result.