Carburetor Adjustment; High Altitude Operation - Echo CS-310 Instruction Manual

Low speed needle (L)

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.
Engine Break-in
New engines must be operated a minimum dura-
tion of two tanks of fuel break-in before carbure-
tor 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 1100 feet above sea level (ASL)
(96.0 kPa). To maintain proper engine operation
and emission compliance above 1100 feet ASL
the carburetor may need to be adjusted by an
authorized ECHO service dealer.
IMPORTANT
If the engine is adjusted for operation above
1100 feet ASL, the carburetor must be
readjusted when operating the engine below
1100 feet ASL, otherwise severe engine damage
may result.
Idle adjusting screw
High speed needle
(H)
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 be-
tween 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 move, then turn
screw out CCW until the saw chain stops moving.
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. Acceler-
ate 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. Con-
tinue 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 3200 r/min.
CAUTION
When starting, idling adjustment speed should be
adjusted to prevent the saw chain from moving.
Correct idle speed is adjusted 3,200 r/min. or 1/4
turn CCW from the point the chain stops moving.
When you experience trouble with the carburetor,
contact your dealer.
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CS-310