Sears 502.25502 manual HOW to Adjust the Carburetor, HOW to Adjust the Throttle Control

Models: 502.25502

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SERVnCE AND ADJUSTMENT

HOW TO ADJUST THE CARBURETOR

The factory settings for the carburetor are for most conditions if

the engine is operated under the following conditions you can adjust the carburetor mixture

ITbe engine has a loss of power or does not run smooth

2 A change from summer to winter operation

3A40 ° change in the operation temperature The carburetor was adjusted at 80 ° at the factory

4The engine is operated above 4 000 feet

If an adjustment is needed, follow the steps below

1Remove the side panet See "How To Remove Tl_e Side Panels"

2 With your hand turn the idle mixture screw in a clockwise

direction until you feel some resistance Turn the main jet screw in a clockwise direction until you feel some resistance CAUTION: Do not over tighten the idle mixture screw or

the main jet screw The carburetor will be damaged

3Turn the idle mixture screw counterclockwise 1_1/4 turns

Turn the main jet screw counterclockwise 1-5/8 turns

4Start the engine Run the engine for several minutes

5Move the throttle control to SLOW position

6Turn the idle mixture screw clockwise until the engine begins to loose speed Note the position of the slot in the idle mix- ture screw

7Slowly turn the idle mixture screw counterclockwise until

the engine runs rough Note the position of the slot in the idle mixture screw

-8Set the idle mixture screw between the two positions in steps 6 and 7

9Move the throttle control to FAST position

10Turn the main jet screw in a clockwise direction until the

engine begins to loose speed (lean mixture) Note the position of the slot in the main jet screw

HOW TO ADJUST THE THROTTLE CONTROL

For the best engine pedormance set the throttle centre! as follows

1 Move the throttle control to the FAST position

3 Loosen the c!amp screw so that the cable for the thrott}e control can move in the cebIe clamp Oo not remove the cable clamp from the centre! bracket or disconnect the cable from the engine control lever

3Move the engine control tever until the slot in the is a!igned (lines up) with the hole in the control bracket as shown

4Tighten the clamp screw Move the throttle control to the SLOW position and then back to the FAST position Check the alignment of the control lever See step 3

5The thrott!e control is now set at the correct speed When the

throttle control is at the FAST position, the engine speed is

3400+ !00 RPM When the throttle control is in the SLOW position, the engine speed is 2 ! 50 ± ! 00 RPM

IMPORTANT: Do not change the engine governor If the engine

governor needs an adjustment, go to the nearest Sears Service

Center. They have the equipment and experience to make the adjustment

Idle Mixture Screw

Jet Screw

1 I Slowly turn the main jet screw in a counterclockwise direc_

tion until the engine runs rough (rich mixture) Note the position of the slot in the main jet screw

12Set the main jet screw between the two posbions in steps 10 and 11

13To check the adjustment operate the engine If the engine stops when the blade(s) are engaged, the carburetor mixture is set too lean Turn the main jet screw counterclockwise

116 turn

14If the engine runs rough when the blade(s) are engaged the carburetor mixture is set too rich Turn the main jet screw

clockwise 1/16 turn

15Again check the engine by engaging and disengaging the

blade(s) If necessary repeat steps 13 or 14

s!o: on Le.ed

I

"_ Thrott!e Con:tel Cable

Cab!e C!amp

Clamp Screw

\

Control Bracket

F-92533

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Sears 502.25502 manual HOW to Adjust the Carburetor, HOW to Adjust the Throttle Control