23
A
B
C
LO
HI
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
mean sea level (MSL) (96.0 kPa and below). To maintain proper
engine operation and emission compliance above 1,100 feet MSL
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 MSL,
the carburetor must be re-adjusted when operating the engine
below
1,100 feet MSL, otherwise severe engine damage can
result.
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 (see page 4) must be
installed 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 operating
temperature.
2. Stop engine.
3. Start engine and turn the high-speed needle (A) rich (CCW)
until the engine runs between 13,500 and 14,500 RPM. Then
turn the low-speed needle (B) rich (CCW) until the engine does
not hesitate when accelerated.
DO NOT REMOVE LIMITER CAPS!
4. Idle Speed Adjustment.
• Turn “idle” speed adjustment screw (C) 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.
