27
ENGINE OVERSPEEDING
1.
If the engine runs wide open (faster than normal), shut the engine off immediately.
2.
Check the condition of the external governor shaft, linkage, governor spring, and speed control assembly for breakage,
stretching or binding. Correct or replace binding or damaged parts.
3.
Follow the governor adjustment procedure and reset the governor - see "Service" in this chapter.
4.
Run the engine. Be ready to shut the engine off if an overspeed problem still exists. If the problem persists, the
engine will require disassembly to inspect the governor gear assembly for damage, binding, or wear.
5.
See Chapter 9 under "Disassembly Procedure" to disassemble the engine.
6.
Remove the governor gear assembly. Repair or replace as necessary.
ENGINE SURGING
1.
Try to stabilize the engine R.P.M. by holding steady the solid link between the governor arm and the carburetor
throttle, using a pliers or fingers.
2.
If the engine R.P.M. stabilizes, the governor or governor adjustment should be checked. See "Service" governor
adjustment procedure in this chapter. If the engine R.P.M. does not stabilize, the engine will require additional
checks, see Chapter 9 under "Troubleshooting".
3.
If the problem persists after the governor adjustment, check the engine R.P.M. found on microfiche card # 30. The
R.P.M. settings are critical. If the R.P.M. setting for high and low speed are within specification and a slight surge is
experienced, increasing the engine idle R.P.M. setting slightly may eliminate this condition.
4.
Check the governor shaft or linkages for binding, wear, or improper hookup. Check the governor spring for adequate
tension. Repair or replace as necessary.
Ú
7
SERVICE
GOVERNOR ADJUSTMENT
8
Ý
PUSH LEVER
TO OPEN
THROTTLE
GOVERNOR SHAFT
GOVERNOR SPOOL
GOVERNOR GEAR
VERTICAL
Figure A
Before 1977
production
Figure B
1977 & Later
production
With the engine stopped, loosen the screw holding the
governor clamp on the governor lever. Rotate the clamp in
a direction that will force the throttle shaft open and allow
the governor follower arm to rest on the governor spool.
Push the governor lever connected to the throttle to the
wide open throttle position. Hold the lever and clamp in
this position while tightening the screw (diag. 7).
GOVERNOR ADJUSTMENT PROCEDURE
FOR SHORT BLOCK INSTALLATIONS
Short block installation on 3-5 h.p. vertical shaft engines
built prior to 1977 may require the governor clamp (tinnerman
style) to be repositioned to work properly. The clamp must
be removed from the governor rod and turned to the same
position as the original engine. Hook the solid link and
spring to the governor lever and position the clamp on the
governor rod. Follow the above governor adjustment
procedure to complete the short block governor set-up.
Units built after 1977 use the normal governor set up
procedure. (diag. 8)
