Kohler K91 Service Manual page 55

spring holds the throttle valve ope n . When the en­
gine is operating (governor gear assembly is rotat­
ing) , the force applied by the regulating pin
against the cross shaft tends to close the throttle
valve . The governor spring tension and the force
applied by the regulating pin are in " equilibriu m "
during operatio n , holding the engine speed con­
stant .
When a load is applied and the engine speed (and
governor speed) decreases , the governor spring
tension moves the governor arm to open the
throttle plate wider. This admits more fuel and re­
stores engine speed . (This action takes place very
rapidly, so a reduction in speed is hardly noticed . )
As the speed reaches the governed settin g , the
governor spring tension and the force applied by
the regulating pin will again be in equilibrium . This
maintains engine speed at a relatively constant
level.
Governed speed may be at a fixed point as on
constant speed applications , or variable as deter­
mined by a th rottle control lever.
Adjustment
£
WARNING:
Overspeed Is Hazardous!
The maximum allowable speed for these engines is
3600 RPM, no load. Never tamper with the governor
setting to Increase the maximum speed. Severe
personal injury and damage to the engine or equip­
ment can result if operated at speeds above
maximum.
INITIAL ADJ USTMENT
Make this initial adjustment whenever the governor
arm is loosened or removed from cross shaft .
Make sure the throttle linkage is connected to gov­
ernor arm and throttle lever on carburetor to en­
sure proper setting . Refer to Figure 6-44 .
Figure 6-44. I nitial Governor Adj ustment.
1 .
Pull the governor arm away from the carbure­
tor as far as it will g o .
Grasp t h e e n d of cross shaft with pliers and
2 .
turn counterclockwise as far as it will g o .
3 . Tighten the pal nut o n governor arm t o
in. lb.
torque.
NOTE : Make sure there is at least
between governor arm and cross shaft bushing nut
to prevent interference .
HIGH SPEED ADJ U ST M ENT
The maximum allowable speed is 3600 RPM , no
load . The actual high speed setting depends on
the application. Refer to the equipment manufac­
t urer ' s instructions for specific high s peed set­
tings . Check the operating speed with a tachome­
ter; do not exceed the maximum . To adjust high
speed sto p :
1 . Loosen the lock nut on high speed adjusting
screw. Refer to Fig ures 6-45.
Figu re 6-45. High Speed Adjusting Screw.
2 . Turn the adjusting screw i n or out until desired
speed is reached . Tighten the lock nut .
3 . Recheck t h e speed with t h e tachometer; read­
just if necessary.
SENSITIVITY ADJUSTMENT
Governor sensitivity is adjusted by repositioning the
governor spring in the holes in governor arm . If
set too sensitive. speed surging will occur with a
change in load . If a big drop in speed occurs
when normal load is applied , the governor should
be set for greater sensitivity .
The standard spring position is in the
from the cross shaft . The position can vary. de­
pending on t he engine application . Therefore,
make a note of (or mark) the spring position be­
fore removing it from the governor arm . Refer to
Figure 6-46 .
1 5
1 11 6"
clearance
t hird
hole
6 . 29