20
Before Adjustment
Check that:
• Air filter is clean and properly installed.
• Spark arrestor screen and muffler are free of carbon.
• Rapid Loader
TM
head with (2) new .080 x 8 in. lines is installed.
Initial Adjustment
1.
With engine off, turn HI speed screw (C) counterclockwise to stop.
2.
Turn LO speed screw (B) midway between stops.
3.
Turn idle screw (A) until tip of screw just touches throttle plate;
then turn three (3) turns clockwise.
Final Adjustment
IMPORTANT
Limiter caps prevent exceeding emission limits and over rich
adjustment, but not over lean adjustment, which can cause engine
failure: Do not exceed recommended HI speed engine R.P.M.
during operation, or for long periods during adjustment.
1.
Start engine, run at idle for one minute.
2.
Complete warm up by running at full throttle for 5 minutes, operat-
ing choke twice to clear air from carburetor chambers.
3.
Run at idle and accelerate to check for smooth transition from idle
to high speed; if engine hesitates, turn LO speed screw (B)
counterclockwise 1/8th of a turn at a time until acceleration is
smooth.
4.
Use a tachometer to adjust idle speed to specifications found on
page 24.
A
B
C
Summary of Contents for GT-251E
Page 25: ...GRASS TRIMMER OPERATOR S MANUAL 25 NOTES...
Page 26: ...26 NOTES...
