Chapter 4 Governors And Linkage; General Information; Operation; Components - Tecumseh TC Series Technician's Handbook

CHAPTER 4 GOVERNORS AND LINKAGE

GENERAL INFORMATION

TC series engines are equipped with pneumatic (air vane) governors. The governor's function is to maintain a R.P .M.
setting when engine loads are added or taken away. Air vane governors are controlled by the air velocity created by fins
on the flywheel. Changes in the engine R.P .M. cause the air vane to move. This movement opens the throttle shaft either
by a link between the air vane and the throttle plate, or the air vane is mounted directly onto the throttle shaft. The throttle
is opened as the engine R.P .M. drops and is closed as the engine load is removed.
This chapter includes governor assembly linkage and speed control illustrations to aid in assembly.

OPERATION

Engine R.P .M. changes cause an increase or decrease in
the air velocity created by the fins on the flywheel. The air
velocity exerts pressure on the air vane while a governor
spring exerts pressure against the air velocity force. The
air vane pivots on the engine blower housing base or is
attached to the throttle shaft of the carburetor. As an engine
load is applied and the engine's R.P .M drop, the air velocity
also drops, allowing the governor spring to pull open the
throttle shaft and increase engine speed (diag. 4-1).
If the engine uses a remote speed control, the bowden
wire will move the speed control plunger or the throttle
shaft. Moving the speed control plunger results in changing
the governor spring tension which increases or decreases
the engine's governed speed.

COMPONENTS

1. AIR VANE
2. BACKLASH SPRING
3. GOVERNOR LINK
4. GOVERNOR SPRING
5. MOUNTING SCREW
6. SPEED ADJUSTMENT SCREW
7. SPEED CONTROL BODY
8. SPEED CONTROL LEVER
9. SPEED CONTROL PLUNGER
TYPE II
1.
9.
4.
16
7.
6.
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TYPE I
TYPE II
TYPE I
Spring Hooked
In Notch
2.
3.
4-1
1.
5.
8.
4.
Insert Throttle Link
4-2