Craftsman 917.270831 owner manual To Adjust Carburetor, Preliminary S EI-IING, Acceleration Test

Choke Closed _

4

I

Choke Lever

TO ADJUST CARBURETOR

The carburetor has been preset at the factory and adjustment should not be necessary. However, minor adjustment may be required to compensate for differences in fuel, temperature, altitude or load. If the carburetor does need adjustment, proceed as follows:

In general, turning the mixture screw in (clockwise) decreases the supply of fuel to the engine giving a leaner fuel/air mixture. Turning the mixture screw out (countemlockwise) increases the supply

of fuel to the engine giving a richer fuel/ air mixture.

IMPORTANT: Damage to the needles and the seats in carburetor may reslut if screw is turned in too tight.

PRELIMINARY S EI-I'ING-

•Be sure you have a clean air filter, and the throttle control cable and choke are adjusted properly (see above).

•With engine off turn idle mixture screw in (clockwise) closing it finger tight and

then turn out (countemlockwise) 1-1/4 to 1-1/2 turns.

FINAL SETTING -

•Start engine and allow to warm for five minutes. Make final adjustments with engine running and s_ift/motion

control lever in neutral (N) position.

•With throttle control lever in slow position, hold throttle lever against idle

speed screw and adjust idle speed screw to obtain 1200 to 1400 RPM.

•While still holding throttle lever against idle speed screw, turn idle mixture screw in (clockwise) until engine begins to die and then turn out

(counterclockwise) until engine runs rough. Turn screw to a point midway between those two positions.

•Continue to hold throttle lever against idle speed screw and adjust idle speed screw to obtain 900 to 1200 RPM. Release throttle lever.

ACCELERATION TEST -

•Move throttle control lever from slow to fast position. If engine hesitates or dies, turn idle mixture screw out

(counterclockwise) 1/8 turn. Repeat test and continue to adjust, if neces-

sary, until engine accelerates smoothly.

High speed stop is factory adjusted. Do not adjust - damage may result. IMPORTANT" Never tamper with the engine governor, which is factory set for proper engine speed, overspeeding the engine above the factory high speed setting can be dangerous, if you think

the engine-govemed high speed needs adjusting, contact your nearest AUTHO- RIZED service center/department, which

has proper equipment and experience to make any necessary adjustments.

ldle Speed

i: crMix_reu

few Throttle

Lever

Idle Speed

Screw

Throttle Lever Idle Mixture

Screw

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