Kohler HD Series Service Manual page 29

Intermediate Control
M
Lever
Q Flyweight(s)
Governed speed setting is determined by position of throttle control. It can be variable or constant, depending on
engine application.
Governor is designed to hold engine speed constant under changing load conditions. Most engines are equipped with
a centrifugal fl yweight mechanical governor. Governor gear/fl yweight mechanism of mechanical governor is mounted
inside oil pan and is driven off gear on camshaft.
This governor design works as follows:
● 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 throttle 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 off set each other to
hold a steady engine speed.
Initial Governor Adjustment
Make this initial adjustment whenever governor arm is loosened or removed from cross shaft. To ensure proper
adjustment, make sure throttle linkage is connected to both governor arm and throttle lever on carburetor.
1. Loosen nut holding governor lever to cross shaft.
2. Move governor lever away from carburetor (wide open throttle) and hold in this position. Do not apply excess
force that may fl ex or distort throttle link.
3. Grasp cross shaft with a pliers and turn shaft clockwise as far as it will go, hold and tighten nut. Then torque nut to
9.5 N·m (84 in. lb.).
14 690 10 Rev. --
N Control Spring
R Governor Gear
KohlerEngines.com
High Speed Adjusting
O
Screw
S Governor Gear Shaft
Governor System
P Regulating Pin
Governor Shaft
T
Retainer
29