Kohler LH630-775 Service Manual page 38

Reassembly Procedure
Reassemble the carburetor using the following steps.
See Figure 5-6.
1. Assemble fuel inlet needle to the float tab. Install
the float, float shaft and inlet needle to the
carburetor upper body. Tighten the screw. Check
float height using the procedure found
previously in the "Adjustments" subsection.
2. Install the slow jet so the stepped end will be
toward the bottom of the carburetor. Make sure
jet is fully seated.
3. Install the low idle adjusting needle and spring.
4. Assemble the carburetor upper body and
carburetor lower body using the four screws.
Torque screws to 1.7 N·m (15 in. lb.).
5. Install the carburetor on the engine following the
procedures in Section 11 - "Reassembly".
Governor
General
The engine is equipped with a centrifugal flyweight
mechanical governor. It is designed to hold the engine
speed constant under changing load conditions. The
governor gear/flyweight mechanism is mounted
inside the closure plate and is driven off the gear on
the camshaft. The governor works as follow:
• Centrifugal force acting on the rotating governor
gear assembly causes the flyweights to move
outward as speed increases. Governor spring
tension moves them inward as speed decreases.
Figure 5-7. Governor Linkage.
Fuel System and Governor
• As the flyweights move outward, they cause the
regulating pin to move outward.
• The regulating pin contacts the tab on the cross
shaft causing the shaft to rotate.
• One end of the cross shaft protrudes through the
crankcase. The rotating action of the cross shaft is
transmitted to the throttle lever of the carburetor
through the external linkage. See Figure 5-7.
• When the engine is at rest, and the throttle is in
the "fast" position, the tension of the governor
spring holds the throttle plate open. When the
engine is operating, the governor gear assembly
is rotating. The force applied by the regulating
pin, against the cross shaft, tends to close the
throttle plate. The governor spring tension and
the force applied by the regulating pin balance
each other during operation, to maintain engine
speed.
• When load is applied and the engine speed and
governor gear speed decreases, the governor
spring tension moves the governor arm to open
the throttle plate wider. This allows more fuel
into the engine, increasing engine speed. As
speed reaches the governed setting, the governor
spring tension and the force applied by the
regulating pin will again offset each other to hold
a steady engine speed.
Section 5
5
5.11