Kohler K91 Service Manual page 52

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S ECOND ARY
ADJUSTMENT
Adjust the two stage regulator as follows .
1 . Turn the secondary adjustment counterclock­
wise as far as it wil l g o . Then turn it clockwise
3 turns.
2 . Connect a source of clean compressed air of
at least 25 psi to t he regulator inlet and de­
press primer button 3 times.
Connect a a t o 1 5 psi pressure gauge t o the
3 .
fuel outlet and press and hold the primer but­
ton . The pressure gauge should read approxi­
mately 2 psi and hold steady at this reading . If
pressure rises slowly . the primary valve is
leaking and t he regulator must be replace d . If
pressure remains constant , proceed .
4 . Remove pressure gauge a n d cover outlet with
a film of soap solution . If a bubble forms , the
secondary valve is leaking .
5 . Slowly turn t h e secondary adjustment t o the
left until the bubble expands, then to the right
one complete turn to stop the leak. If leaking
persists, replace the reg ulator.
GOVERNOR
Engine speed governors i n the K series of engines
(with t he exception of the K9 1 ) are of the centrifu­
gal flyweight mechanical type. The K9 1 utilizes a
flyball . The governor gear and flyweight mecha­
nism are contained within the crankcase . The gov­
ernor gear is driven by a gear on the camshaft .
Operation
In operation , centrifugal force causes the fly­
weights (or flyball) to move outward with an in-
6.26
PRESSURE CHAMBER
(PRIMARY
T
Figure 6-38. wo Stage Reg
crease in speed and inward with a decrease . As
the flyweights move outward , they force the regu­
lating pin of the assembly to move outward . The
regu lating pin contacts the tab on the cross shaft ,
causing the shaft to rotate wit h changing speed .
One end of the cross shaft protrudes through the
side of the crankcase . Through external linkage
attached to the cross shaft , the rotating action is
transmitted to the throttle on t he carburetor.
When the engine is not running , t he governor
spring holds the throttle in the open position .
When a normal load is applie d to an operating en­
gine, the speed tends to decrease . The resulting
rotation of the cross shaft acts against the gover­
nor spring , opening the throttle wider. This action
admits more fuel , restoring engine spee d . As
speed again reaches the governed setting, the
shaft rotates to close the throttle valve enough to
maintain governed speed .
Governed speed may be at a fixed point as on
constant speed applications or variable as deter­
mined by a throttle control sett ing .
I nitial Adjustment
Governors are adjusted at the factory. Further ad­
justment should not be necessary u nless the gov­
ernor arm or linkage work loose or become d is­
connected . The need for governor adjustment may
be ind icated by e ngine speed surges or h unting
with changes in load or by a considerable drop in
engine speed when a normal load is applied . The
i nternal governor mechanism is basically similar for
all K series engines . The external mechanism is
d ifferent on the K24 1 through K34 1 models. Be
sure to follow the adjustment procedure for the
model engine being serviced .
1 0
PSI )
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SECONDARY DIAPHRAGM
u la tor
.
K91 , K 1 41 . K 1 6 1 , K 1 81
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CHAMBER