LawnMaster NPTBSP2609A, Руководство по обслуживанию, Страница: 23 / 42

23
AIR & FUEL SYSTEM
The requirements of carburetor flow rate:
■ With the flowmeter: The idle speed flow rate is 0.26-0.28 lbs./h (0.12-0.13 kg/h). The high-speed
flow rate is 0.88-0.97 lbs./h (0.40-0.44 kg/h).
■ Without the flowmeter: The idle speed is 3000+1000 rich. Adjust to maximum speed, then adjust the
H screw counter-clockwise 1/4 turn.
To adjust the carburetor, a tachometer is needed (Fig. 29). When testing the speed, the tachometer
should be placed near the spark plug of the brush cutter.
NOTE: When adjusting the carburetor, place the brush cutter on a flat stable surface in an open area.
Keep the cutter off the ground and away from any objects when making adjustments. Keep all parts of
your body away from the brush cutter blade.
■ Start the cutter and run at half or low throttle for about 2 minutes, to warm the engine.
■ Adjust the H screw: while running the cutter at full throttle, first turn the H screw clockwise slightly
with the carburetor adjustment tool, and observe the RPM displayed on the tachometer to verify
the correct adjustment direction (clockwise or counter-clockwise) for reaching the max no load
speed. Then turn the H screw slowly in the correct direction, and observe the RPM displayed on the
tachometer until it reaches the max speed (Fig. 30).
Fig. 28 Fig. 27
T Screw
L Screw
H Screw
Fig. 29
rpm
CLOCK SET
A B C D
E F G RESET
21:42
Max speed
NPTBSP2609A About 10000-10800RPM