Governor System GOVERNOR Engine is equipped with a centrifugal fl yweight mechanical governor. It is designed to hold engine speed constant under changing load conditions. Governor gear/ fl yweight mechanism is mounted inside closure plate and is driven off gear on camshaft. Governor Adjustments NOTE: Do not tamper with governor setting. Overspeed is hazardous and could cause personal injury. Initial Adjustment Procedure Make this adjustment whenever governor lever is loosened or removed from cross shaft. 1. Make sure throttle linkage is connected to governor lever and throttle lever on carburetor. 2. Loosen hex nut holding governor lever to cross shaft. 3.
Move governor lever towards carburetor as far as it will move (wide open throttle) and hold in position. 4. Insert a nail into hole on cross shaft and rotate shaft counterclockwise as far as it will turn, then torque hex nut to 6.8 N·m (60 in. lb.). Sensitivity Adjustment Governor sensitivity is adjusted by repositioning governor spring in holes on governor lever. If speed surging occurs with a change in engine load, governor is set too sensitive. If a big drop in speed occurs when normal load is applied, governor should be set for greater sensitivity. 1. To increase sensitivity, move spring closer to governor cross shaft. 2.
To decrease sensitivity, move spring away from governor cross shaft. Governor Components High Speed RPM Adjustment NOTE: When throttle and choke control cables are routed side-by-side, especially under a single clamp, there must be a small gap between cables to prevent internal binding. After high- speed setting has been complete, check that there is gap of at least 0.5 mm (0.020 in.) between control cables. 1. With engine running, move throttle control to fast. Use a tachometer to check RPM speed. 2. Loosen lock nut on high speed adjusting screw. Turn screw outward to decrease, or inward to increase RPM speed. Check RPM with a tachometer. 3.
When desired RPM speed is obtained, retighten lock nut. ● Centrifugal force acting on rotating governor gear assembly causes fl yweights to move outward as speed increases. Governor spring tension moves them inward as speed decreases. ● As fl yweights move outward, they cause regulating pin to move outward. ● Regulating pin contacts tab on cross shaft causing shaft to rotate. ● One end of cross shaft protrudes through crankcase. Rotating action of cross shaft is transmitted to throttle lever of carburetor through external linkage. ● When engine is at rest, and throttle is in fast position, tension of governor spring holds throttle plate open.
When engine is operating, governor gear assembly is rotating. Force applied by regulating pin, against cross shaft, tends to close throttle plate. Governor spring tension and force applied by regulating pin balance each other during operation, to maintain engine speed. ● When load is applied and engine speed and governor gear speed decreases, governor spring tension moves governor arm to open throttle plate wider. This allows more fuel into engine, increasing engine speed. As speed reaches governed setting, governor spring tension and force applied by regulating pin will again offset each other to hold a steady engine speed. 66 690 01 Rev.
C KohlerEngines.com 25 A B C D E F A Flyweight B Regulating Pin C Cross shaft D Governor Lever E Throttle Linkage F Throttle Lever