Kohler KT17 Service Manual

SECTION 4
FUEL
SYSTEM AND GOVERNOR
GOVERNOR SYSTEM
WARNING: Never tamper with governor settings
to increase the maxium speed of the
engine. Overspeeding can cause equip-
ment parts to exceed design limita-
tions, resulting in component failures.
Parts
breaking under excess stress
can become lethal missiles if thrown
off by the equipment. Broken parts
flying through the air can injure or
kill.
These engines are equipped with a centrifugal
flyweight mechanical governor. The governor
gear/flyweight mechanism is mounted within the
crankcase and driven off a gear on the camshaft.
Governor Operation
Centrifugal force causes the flyweights to move
outward as speed increases and inward as speed
decreases. As the flyweights move outward, they
force the rod portion of the assembly to push
outward. The rod, in turn, contacts a tab on the
governor cross shaft causing it to rotate with
changing speed. One end of the cross shaft pro-
trudes through the side of the crankcase. Through
external linkage, the action of the cross shaft is
transmitted to the throttle (or butterfly) valve in
the carburetor.
When the engine is at rest and the throttle is in the
"Fast" position, the tension of the governor spring
holds the throttle valve open. When the engine is
operating (governor gear is turning), the force
applied by the governor gear against the cross
shaft tends to close the throttle valve. The gover-
nor spring tension and the force applied by the
governor gear are in "equilibrium" during opera-
tion and hold the engine speed constant.
When a normal load is applied and engine (and
governor) speed decrease, the tension of the
governor spring rotates the governor arm to open
the throttle valve wider. This admits more fuel and
restores engine speed. (With the governor properly
adjusted, this action takes place so rapidly, a
reduction in speed is hardly noticed.) As speed
reaches the governed setting, the tension of the
governor spring and the force applied by the
governor gear will again be in equilibrium, main-
taining speed at a relatively constant level. For
identification of the governor components men-
tioned above, see Figure 4-7.
Governed speed may be at a fixed point as on
constant speed applications, or variable as deter-
mined by a throttle control.
22
Governor Flyweight
Gear
Lever
Governor
Spring
Figure 4-7. Governor Components
Adjustments
Throttle
Control
High
Speed
Stop
Tab
Governors are adjusted at the factory and further
adjustment should not be necessary. Governor
adjustment may be indicated if engine speed surges
with changing load, or if speed drops considerably
when normal load is applied.
Speed Adjustment- Maximum allowable speed
for
these engines is 3600 RPM, no load. Check
operating speed with a hand tachometer. Do not
exceed this speed. If adjustment is necessary
loosen the governor speed adjusting screw and
pivot the high speed stop tab until desired speed
setting is reached, then tighten the screw.
Sensitivity Adjustment - Governor sensitivity
can be adjusted by repositioning the governor
spring in the holes on the governor arm. If set too
sensitive, speed surging will occur with change of
load. If a big drop in speed occurs when normal
load is applied, the governor should be set for
greater sensitivity.
Normally, the governor spring is placed in the fifth
hole from pivot of the governor arm and in the
sixth hole from pivot on the throttle control lever.
To make governor control more sensitive, increase
governor spring tension by moving the spring end
closer to the center of the governor arm. To allow
broader governor control but less sensitivity, de-
crease spring tension by moving the spring toward
the end of the arm.

Kohler KT17 Specifications

General

Brand	Kohler
Model	KT17
Category	Engine
Language	English