SERVICE AND ADJUSTMENTS TO ADJUST CARBURETOR , ................... i The carburetor (See Fig. 40 and Fig. 42) has been pre-set atthe factory and readjustment should not be necessary. However, if the carburetor does need to be adjusted, proceed as follows: CARBURETOR o Close the high speed adjusting screw by hand ® Then ope n it 141/4 to t-1/2 turns . .... Do not overtighten. IDLE ADJUSTING SCREW (Close finger tight only) e Close the idle adjusting screw by hand. Do not overtighten HIGH SPEED ADJUSTING SCREW (C!osefingertighlonly) Start the engine and let it warm up. e Then open it 1-1/4 to t-1/2 turns. i FIGo40 ® Set the throttle control to FAST.
Adjust the high speed adjusting screw in until the engine speed or sound alters Adjust the screw out until the engine speed sound altersr Note the difference between the two limits and set the screw in the middle of the TO ADJUST: o Clean the spark plug by carefully scraping elec- trodes (do not sand blast or use a wire brush). O Be sure the spark plug is clean and free of foreign matedal. Check electrodes gap (See Fig. 41) with a wire feeler gauge and reset the gap to 030 inch if necessary° range. ® Set the throttle control to SLOW Adjust the idle adjusting screw in until the engine speed drops, then adjust the screw out until the engine speed drops.
Note the difference between the two limits and set the screw in the middle of the range. ® If the engine tends to stall under load or not accel- erate from low speed to high speed properly, adjust the high speed screw out in 1/8 turn increments until the problem is resolved ,030 GAP e Let the engine run undisturbed for 30 seconds between each setting to allow the engine to react to the previous adjustmenls IMPORTANT: NEVER TAMPER WITH THE ENGINE GOVERNOR, WHlCH IS FACTORY SET FOR PROPER ENGINE SPEED OVERSPEEDtNG THE ENGINE ABOVE THE FACTORY HIGH SPEED SETTING CAN BE DANGEROUS.
IF YOU THINK THE ENGINE - GOVERNED HiGH SPEED NEEDS ADJUSTING, CONTACT YOUR NEAREST SEARS SERVICE CENTER, WHICH HAS THE PROPER EQUfPMENT AND EXPERIENCE TO MAKE ANY NECESSARY ADJUSTMENTS. TO ADJUST OR REPLACE THE SPARK PLUG ii i i FIG. 41 TO REPLACE: e If you need a new spark plug, use only the proper replacement spark plug (See page 4 ) ® Set the gap to .030 Before installing the spark plug, coat its threads lightly with graphite grease to insure easy removal. o Tighten the plug firmly into the engine ® If a torque wrench is available, torque the plug to 18 to 23 ft - Ibs.
if you have difficulty starting your snow thrower, you may need to adjust or replace the spark plug Follow the instructions below Replace the spark plug if electrodes are pitted or burned or if the porcelain is cracked 25