5.13
Section 5
Fuel System and Governor
5
4. Remove the upper brass bushing using one of the
following procedures:
a. Use a slide hammer type bearing puller.
b. Use a #3 (for 5-32 dia. hole) screw extractor.
Secure extractor in a vise. Turn carburetor on
to the extractor. While pulling on the
carburetor, lightly tap the carburetor casting
with a hammer or use a size 12-28 tap if a #3
screw extractor is not available.
Installing Kit Parts
WARNING: Prevent Eye Injury!
Suitable eye protection (safety glasses, goggles, or face
shield) should be worn for any procedure involving the use
of compressed air, punches, hammers, chisels, drills, or
grinding tools.
1. Before installing kit parts, thoroughly clean the
carburetor body with compressed air.
2. Install the new bushing through the new lever
and align the slot in the bottom of the lever over
the lever stop pin. To insure the proper alignment
of the upper bushing and the lower shaft hole use
a 3/16 diameter drill blank to align the bushing as
it is pressed into the casting.
3. Install choke shaft and spring assembly with the
lower spring tang installed in the second notch
from the right. See Figure 5-16.
Figure 5-16. Choke Lever with Cap Removed.
4. Loosely attach the choke plate to the choke shaft
using the two screws provided in the choke
repair kit. Apply Loctite
®
No. 609 to the threads
of the choke plate retaining screws. Secure these
screws ONLY after the choke plate is properly
aligned in the choke plate bore. To align choke
plate, insert a 0.010 in. shim between the top right
edge of the choke plate and bore. See Figure
5-17. Then while pushing down on the top of the
choke shaft, tighten screws securely.
Figure 5-17. Measuring Clearance (Air Cleaner
Removed For Clarity).
5. Check choke shaft and choke plate for freedom of
movement by performing the following:
a. Using the choke lever, close the choke plate.
The choke lever and choke plate should move
in unison.
b. While holding the choke lever in the closed
position, push on the long side of the choke
plate. The choke plate should open and spring
closed freely.
c. While holding the choke lever in the wide
open position, the choke plate should be
against the wide open choke plate stop pin.
6. Install new dust cover by pushing it down until it
snaps into place.
7. After the carburetor is reinstalled on the engine,
recheck choke system for freedom of movement
by moving the wire link in the direction to close
the choke the wire link in the direction to close
the choke and releasing it. The link should move
freely in both directions.
Governor
These engines are 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 crankcase and is driven off the
gear on the camshaft.
Operation
Centrifugal force acting on the rotating governor gear
assembly causes the flyweights to move outward as
speed increases and inward as speed decreases. As the
flyweights move outward, they cause the regulating
pin to move outward.
Bottom of
Spring in
Position 2
Top View Showing
Spring Position
