How To Adjust The Carburetor; How To Adjust The Throttle Control - Craftsman 502.25502 Owner's Manual

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
I Tbe engine has a loss of power or does not run smooth
2 A change from summer to winter operation
3 A40 ° change in the operation temperature The carburetor
was adjusted at 80 ° at the factory
4 The engine is operated above 4 000 feet
If an adjustment is needed, follow the steps below
1 Remove 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
3 Turn the idle mixture screw counterclockwise 1_1/4 turns
Turn the main jet screw counterclockwise 1-5/8 turns
4 Start the engine Run the engine for several minutes
5 Move the throttle control to SLOW position
6 Turn the idle mixture screw clockwise until the engine begins
to loose speed Note the position of the slot in the idle mix-
ture screw
7 Slowly turn the idle mixture screw counterclockwise until
the engine runs rough Note the position of the slot in the idle
mixture screw
Set the idle mixture screw between the two positions in
steps 6 and 7
Move the throttle control to FAST position
Turn 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
-8
9
10
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
3 Move the engine control tever until the slot in the is a!igned
(lines up) with the hole in the control bracket as shown
4 Tighten 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
5 The 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
12 Set the main jet screw between the two posbions in steps 10
and 11
13 To 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
1 16 turn
14 If 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
15 Again check the engine by engaging and disengaging the
blade(s) If necessary repeat steps 13 or 14
Control Bracket
s!o: on Le.ed
I
\
"_ Thrott!e Con:tel Cable
Cab!e C!amp
Clamp Screw
F-92533 25