Kohler K91 Service Manual page 49

GAS FUEL SYSTEM
The main components of the gas fuel system as
used with Kohler K series eng ines are :
Liquified petroleum gas tank
Primary regulator
Secondary regulator
Gas Carburetor
I n some applications , the primary and secondary
regulators are combi ned in one two-stage unit .
The gas carburetor and secondary regulator (or
two stage regulator) are normally furnished with
the engine. Other components are furnished by
the fuel supplier.
There are some isolated instances in which the
equipment manufacturer supplies the entire fuel
system for operation with gas. Information on
servicing these systems must be obtained from
the equipment manufacturer.
Depending on the air temperature and the mixture
of gasses in t he tank, pressure at the outlet of the
tank can be as high as 1 80 to 200 psi . Refer to
Fig ure 6-33 .
Secondary Regulator
The secondary regulators used on Kohler engines
are compact single diaphragm types . This type
regulator accurately regulates the flow of gas to
the carburetor and shuts the gas off automatically
when the demand for gas ceases . If the regulator
fails , it must be replaced or reconditioned by an
authorized gas equipment repair shop.
tempt to repair a faulty regulator.
Secondary regulators used on Kohler engines re­
quire only one adjustment . Ensign Models F or F 1
reg ulators have a n idle adjustment . This adjust­
ment should be performed while the engine is run­
n ing . Refer to Figure 6-34 .
Garretson Model S , SD and KN regulators have a
lockoff or fuel control adjustment . Use the follow­
ing procedure to make this adjustment . Refer to
Figures 6-35 and 6-36 .
NOTE : The regulator should b e mounted as close
to vertical as possible , and adjusted in the position
in which it will be mounted on the engine.
1 . Connect regulator in let to a source of clean
compressed air, not over 1 0 psi . Do not con­
nect to a gas supply.
2 . Turn air supply on.
3 . I f the regulator being adjusted i s a Model KN ,
open the lock off adjusting screw until air just
starts flowing through the regulator.
4 . Turn the lock off adj usting screw i n slowly until
air flow stops.
NOTE : A soap bubble test is a good way to check
for complete shutoff . If bu bbles ind icate that air is
still flowing, turn the screw in one more full turn .
1 60
1 40
1 20
1 00
- 80
60
w
a:::
:::J
� 40
UJ
a:::
a..
20
o
F i g u re
Do not at­
I DL E
A DJ USTME
Figure
VAPOR P RESSURE
P ROPANE
-40 -20 0 +20 +40 + 60 +80
TEMP E RATU RE ( O FAHREN HE I T )
6-33.
L P Gas Vap o r Pressure Curve.
6-34.
M o d e l F a n d F1 Secondary
Regu lators.
I
I
I
1
I
1
_ _ _ _ _
.... .. .. .. .. .. . P RI MER
VENT (OR
BALAN C E L I N E )
FUEL
OUTL ET
6 . 23