Maintenance, repair, or replacement of the emission control devices and systems, which are being done at the customers expense, may be performed by any non-road engine repair establishment or individual. Warranty repairs must be performed by an authorized engine manufacturer's service outlet.

TO ADJUST THROTTLE CONTROL

The throttle control has been preset at the factory and adjustment should not be nec- essary. Check adjustment as described below before loosening cable. If adjust- ment is necessary, proceed as follows:

1.With engine not running, move throttle control lever from slow to choke posi- tion. Slowly move lever from choke to fast position.

2.Check that holes "A" in governor

control lever and hole in governor plate line-up. If holes "A" are not aligned,

loosen clamp screw and move throttle

cable

until holes are aligned. Tighten

clamp

screw securely.

 

Governor

ControU Lever

Governor

PUate

HoUes

ThrottUe

CUamp

CaMe

Screw

 

TO ADJUST CARBURETOR

 

NOTE: The carburetor on this engine is low emission. It is equipped with an idle fuel adjusting needle with a limiter cap, which allows some adjustment within the limits allowed by the cap. Do not attempt to remove the limker cap. The limiter cap cannot be removed without breaking the adjusting needle.

The carburetor has been preset at the factory and adjustment should not be nec- essary. 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 idle mixture valve in (clockwise) decreases the supply of fuel to the engine giving a leaner fuel/air mix- ture. Turning the idle mixture valve out

(counterclockwise) increases the supply

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

mMPORTANT: Damage to the needle

valve and the seat in carburetor may result if screw is turned in too tight.

PRELIMINARY SETTING -

1.Air cleaner assembly must be assem- bled to the carburetor when making carburetor adjustments.

2.Be sure the throttle control cable is adjusted properly (see above).

FINAL SETTING -

1.Start engine and allow to warm for five minutes. Make final adjustments with engine running and shift/motion control lever in neutral (N) position.

2.Move throttle control lever to slow posi- tion. With finger, rotate and hold throttle lever against idle speed screw. Turn idle speed screw to attain 1750 RPM.

3.While still holding throttle lever against

idle speed screw, turn idle mixture valve full travel clockwise then coun-

terclockwise until engine runs rough. Turn valve to a point midway between

those two positions. Release throttle lever.

ACCELERATION TEST -

4.Move throttle control lever from slow

to fast position. If engine hesitates or dies, turn idle mixture valve out (coun-

terclockwise) 1/8 turn. Repeat test and continue to adjust, if necessary, until engine accelerates smoothly.

High speed stop is factory adjusted. Do not adjust - damage may result. mMPORTANT: Never tamper with the engine governor, which is factory set for proper engine speed. Overspeed-

ing the engine above the factory high speed setting can be dangerous. If you

think the engine-governed high speed needs adjusting, contact a Sears or other qualified service center, which has proper equipment and experience to make any necessary adjustments.

Idle Speed [-

Throttle

Screw

Lever

With Limiter

25

Page 25
Image 25
Craftsman 917.273638 manual To Adjust Carburetor, Preliminary Setting, Final Setting, Acceleration Test