Echo CS-341 - Manual (Page 22)

22
CaRbuRetoR aDjustment
Engine Break-In
New engines must be operated a minimum duration
of two tanks of fuel break-in before carburetor ad-
justments 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 perfor-
mance up to 1,100 feet above sea level (ASL) (96.0
kPa). To maintain proper engine operation and emis-
sion compliance above 1,100 feet ASL the carbure-
tor 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 dam-
age may result.
B
A
BEFORE MAKING ADJUSTMENTS:
• The correct spark plug must be clean and properly
gapped.
• The air filter element must be clean and properly installed.
• The muffler spark arrestor screen and exhaust port must
be clear of carbon.
• The standard bar and chain combination must be in-
stalled to the power head, and properly tensioned.
LOW ALTITUDE ADJUSTMENT
Engines that have been adjusted to operate at high altitudes
must be readjusted to operate properly at altitudes below
2000 feet.
1. Start engine and run for several minutes to reach operat-
ing temperature.
2. Stop engine. Remove grommet cover (A) over “H” and “L”
limiter needles.
3. Start engine and turn the high-speed needle rich (CCW)
until the engine runs between 11,500 and 12,000 RPM.
Then turn the low-speed needle rich (CCW) until the en-
gine does not hesitate when accelerated.
DO NOT REMOVE LIMITER CAPS!
4. Idle Speed Adjustment.
• Turn “idle” speed adjustment screw (B) CW until the saw
chain begins to move, then turn the screw CCW until saw
chain stops moving. Turn screw CCW an additional 1/4
turn.
5. 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 stops or stalls after full warm up return
the unit to your authorized ECHO dealer for adjustment.
6. Install grommet cover (A) over “H” and “L” limiter needles.
HIGH ALTITUDE ADJUSTMENT
High altitude adjustment may be required for proper opera-
tion of this engine above 2000 feet.
1. Start engine and run for several minutes to reach operat-
ing temperature.
2. Stop engine. Remove grommet cover (A) over “H” and “L”
limiter needles.
3. Start engine and turn the HI speed needle lean (CW) until
the engine runs between 11,500 and 12,000 RPM. Then
turn the LO speed needle lean (CW) until the engine does
not hesitate when accelerated.
DO NOT REMOVE LIMITER CAPS!