Adjusting Carburetor - Echo CS-2510TES Service Manual

CS-2510TES
250Ts, 250TCs
4-7 Adjusting carburetor (continued)

4-7-3 Adjusting carburetor

3. Set idle engine speed to 4,000 r/min by turning Throttle adjust screw (D). Engine speed should be
stable at 4,000 +/- 50 r/min after Throttle adjust screw adjustment.
4. Turn L mixture needle (B) counterclockwise reducing engine idle speed 800 r/min to set idle speed at
3,200 r/min. The engine idle speed ranges 3,100 - 3,300 r/min.
NOTE : Engine speed must be allowed to stabilize a minimum of 20 seconds after each adjustment of L
mixture needle to assure accurate tachometer readings.
6. Before adjustment, WOT engine speed should be 12,000 r/min or less. If engine speed is higher, turn
H mixture needle (C) counterclockwise until 12,000 r/min is achieved. Turn H mixture needle (C) clock-
wise in 1/8 turn increments with the engine at idle, then squeeze throttle trigger and check WOT engine
speed. Adjust H mixture needle (C) to reach WOT engine speed within 12,400 - 12,600 r/min. To make
the fi nal WOT engine speed adjustment, turn H mixture needle (C) clockwise in 1/4 turn with the engine
at idle, then squeeze throttle trigger and check WOT engine speed. The WOT engine speed should be
within 12,700 - 13,100 r/min range.
7. Start engine, and verify engine idle speed ranges from 2,800 to 3,600 r/min, and WOT engine speed
ranges from 12,700 to 13,100 r/min. Make sure the chain does not rotate when engine is idling. When
fi nal adjustment is completed, the engine should idle, accelerate smoothly, and attain WOT per above
specifi cations.
NOTE: WOT and idle engine speed in fi eld operation may vary from fi nal adjustment specifi cations due
to changing ambient conditions and fuel. Safe engine speed variances should be within the WOT and
Idle engine speed ranges listed in Section "1-2 Technical data", otherwise the carburetor should be read-
justed.
FUEL SYSTEM
D
C
B
A
1. Start and warm engine for 100 seconds alternat-
ing engine speed between WOT 5 seconds and idle
5 seconds. Turn H mixture needle (C) counterclock-
wise until engine speed drops to approx. 12,000 r/
min at WOT.
NOTE : Do not run engine at high speed without
load (cutting) longer than 10 seconds, or engine
damage may occur.
2. Adjust L mixture needle (B) using D-shaped
tool (A) to reach maximum engine speed just
before lean drop off.
If chain starts to rotate during adjustment,
decrease engine speed by turning throttle adjust
screw (D) counterclockwise untill chain stops and
then readjust L mixture needle (B).
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