Poulan PD18H42STA User Manual - Page 25

SERVICE AND ADJUSTMENTS ENGINE 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 CABLE (See Fig. 32) The throttle control has been preset at the factory and adjustment should not be necessary. Check adjustment as described below before loosening cable. If adjustment is necessary, proceed as follows: • With engine not running, move throttle control lever from slow to choke position. Slowly move lever from choke to fast position. • Check to see if hole in throttle lever and hole in speed control bracket are aligned. • If holes are not aligned, loosen cable clamp screw and align the holes by inserting a pencil or a 1/4" drill bit through both holes. • Pull throttle cable up to remove slack and tighten cable clamp screw. Remove alignment pencil or drill bit. TO ADJUST CARBURETOR (See Fig. 33) 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 adjusting needles in (clockwise) decreases the supply of fuel to the engine giving a leaner fuel/air mixture. Turning the adjusting needles out (counterclockwise) 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 RESULT IF NEEDLE IS TURNED IN TOO TIGHT. 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 limiter cap. The limiter cap cannot be removed without breaking the adjusting needle. • Be sure you have a clean air filter and the throttle control cable is adjusted properly (see above). • Start engine and allow to warm for five minutes. Make adjustments with engine running and shift/motion control lever in neutral (N) position. • Idle speed setting - With throttle control lever in slow position, engine should idle at 1750 RPM. If engine idles too slow or fast, turn idle speed adjusting screw in or out until correct idle is attained. • Idle fuel needle setting - With throttle control lever in slow position, turn idle fuel adjustment needle in (clockwise) until engine begins to die and then turn out (counterclockwise) until engine runs rough.Turn needle to a point midway between those two positions. • Recheck idle speed. Readjust if necessary. ACCELERATION TEST • Move throttle control lever from slow to fast position. If engine hesitates or dies, turn idle fuel adjusting needle out (counterclockwise) 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. IMPORTANT: NEVER TAMPER WITH THE ENGINE GOVERNOR, WHICH IS FACTORY SET FOR PROPER ENGINE SPEED.OVERSPEEDINGTHE ENGINE ABOVETHE FACTORY HIGH SPEED SETTING CAN BE DANGEROUS. IF YOU THINK THE ENGINE-GOVERNED HIGH SPEED NEEDS ADJUSTING, CONTACTYOUR NEAREST AUTHORIZED SERVICE CENTER/ DEPARTMENT, WHICH HAS PROPER EQUIPMENT AND EXPERIENCE TO MAKE ANY NECESSARY ADJUSTMENTS. CABLE CLAMP SCREW SPEED CONTROL BRACKET IDLE SPEED ADJUSTING SCREW FIG. 32 THROTTLE LEVER IDLE FUEL ADJUSTING NEEDLE 25 FIG. 33