Service Manual

Testing LP Gas Fuel System (Fig. 5)
Preliminary
1. Park machine on a level surface, stop engine, en-
gage parking brake, and remove key from the ignition
switch.
2. Read carefully Precautions for Working on Liquid
Propane Gas Systems before proceeding to any of the
tests.
3. Make sure there is sufficient LP gas in the tank to run
the engine before each test.
Test Vacuum Fuelock Filter
1. Connect 0 to 160 PSI test gauge in
–line between the
fuel outlet of the vacuum fuelock filter and the vaporizer
regulator.
2. Connect 0 to 10 inches (H
2
O) vacuum gauge in–line
between the vacuum signal port of the vacuum fuelock
filter and the vacuum hose.
3. Make sure all fittings are tight and the fuel cut out
valve on the fuel tank is open.
4. If the engine is operable, start the engine. If the en-
gine i
s unable to start, crank the engine for sufficient time
to read the gauges.
5. If the vacuum gauge is reading 2 inches or more, the
pressure gauge should read about 150 PSI (nominal).
This indicates the vacuum fuelock is open.
6. Stop the engine. The vacuum gauge should read
less than 2 inches. The pressure gauge should read
about 0 PSI (nominal). This indicates the vacuum fue-
lock is closed.
7. If the vacuum gauge is reading less than 2 inches
with the engine cranking or running, the pressure gauge
should read about 0 PSI (nominal). Check the connec-
tions to the vacuum gage to make sure there is no leak-
age.
8. Shut off engine, remove gauges, and reconnect
hoses and fittings.
Test Vaporizer–regulator
1. Connect 0 to 5 PSI test gauge to the primary pres-
sure test port on the vaporizer regulator (Fig. 6).
2. Connect 0 to 10 inches (H
2
O) vacuum gauge in–line
between the vacuum signal port of the vaporizer–regula-
tor and the vacuum hose from the air intake manifold.
3. Make sure all fittings are tight and the fuel cut out
valve on the fuel tank is open.
5
1
2
46
3
7 7
4. If the engine is operable, start the engine. If the en-
gine is unable to start, crank the engine for sufficient time
to read the gauges.
5. If the vacuum gauge is reading 2.7 inches or more,
the pressure gauge should read about 4.0 to 5.0 PSI.
This i
ndicates the vaporizer–regulator is operating prop-
erly.
6. Stop the engine. The vacuum gauge should read
less than 2.7 inches, the pressure gauge should read
about 0
PSI (nominal). This indicates the vaporizer–reg-
ulator is locked off.
7. If the vacuum gauge is reading less than 2.7 inches
with the engine cranking or running, the pressure gauge
should read about 0 PSI (nominal). Check the connec-
tions to the
vacuum gage to make sure there is no leak-
age.
8. Shut off engine, remove gauges, and reconnect
hoses and fittings.
Liquid Propane Gas
Conversion Kit
Figure 6
1. Vacuum port
(1/8 inch NPT)
2. LP gas inlet
(1/4 inch NPT)
3. To carburetor air intake
(1/8 inch NPT)
4. Primary press. test port
(1/8 inch NPT)
5. Vaporized fuel outlet
(3/8 inch NPT)
6. Idle adjustment screw
7. Water connection
(1/4 inch NPT)
Workman 3000/4000 Series
Page 11 – 9
Rev. D
Liquid Propane Gas Conversion Kit