Winco PSS75LS User Manual

CHANGING FUEL TYPES FOR

PSS50LS & PSS75LS

WITH GM 5.7L ENGINES

CHANGING FROM NG TO LP

CHANGING THE REGULATOR:

1. Turn off fuel supply.

2. Remove the fuel line from carburetor at the demand regulator.

3. Remove the cap on the upright column of the regulator. This will expose
the pressure spring adjusting screw. Back off the spring adjusting screw
so there is just enough room to replace the cover. Replace the cap.

4. Invert the regulator so it is positioned with the column pointing down.

5. Reconnect the fuel line at the regulator.

6. Remove the 1/8 NPT plug (the one closest to fuel solenoid) located on
what is now the top of the regulator. Connect a fuel pressure meter or a
manometer where the plug has been removed. Put the gen-set in the run
mode. As the unit starts to crank the fuel solenoid will open and you
should get a pressure reading of between 4 to 6 ounces (7 to 11 inches of
water column).

7. If the pressure is correct, remove the meter and reinstall the pipe plug.

CHANGING THE DIAPHRAM:

1. Install Winco part # 98574-701 (diaphragm) in the fuel mixer.

CHANGING THE TIMING:

1. On the GM 5.7 Liter engine you will have to change the timing advance

degrees from 36° to 26°.

RESETTING THE AIR TO FUEL MIXTURE

1. Once all the above steps have been completed the last item will be to
adjust the air to fuel mixture. This mixture adjustment is located on the
fuel mixer. You will need a 7/16 open end wrench to adjust it. The adjust
is marked with an “L” & “R” meaning lean and rich and it only turns about
60 degrees.

2. Start the engine and very gently make adjustment to the air to fuel mixture
to smooth the engine out. NOTE: In some cases you may have to adjust
it rich or lean just to get the engine to start.

3. Once you have the engine running smooth, stop and then restart it and
recheck your fuel adjustment.

4. Repeat this process until the engine starts smoothly, comes to speed
properly, and runs smoothly.

5. The starting should be rechecked at a later date when the engine is cool
to make sure it still works properly.

CHANGING FROM LP TO NG

1. Turn off fuel supply.

2. Remove the fuel line from carburetor at the demand regulator.

3. Invert the regulator so the column is in the upright position. Remove the
cap on the upright column of the regulator. This will expose the pressure
spring adjusting screw. Turn the screw all the way out (CCW) and then
back in (CW) about 8 turns. The plug should be approximately half way
down for initial starting. Replace the cap.

4. Reconnect the fuel line at the regulator.

5. Remove the 1/8 NPT plug (the one closest to fuel solenoid) located on
what is now the top of the regulator. Connect a fuel pressure meter or a
manometer where the plug has been removed. Put the gen-set in the run
mode. As the unit starts to crank the fuel solenoid will open and you
should get a pressure reading of between 4 to 6 ounces (7 to 11 inches of
water column).

6. If the pressure is correct, remove the meter and reinstall the pipe plug.
Next remove the 1/8 inch NPT plug on the carburetor side of the regulator
and install the pressure meter. Depress the run button on the controller.
As soon as the solenoid opens the pressure should rise 2.5 to 3 oz. just as
the engine starts to crank. If it is within this range replace the cap on the
column. If not, adjust the screw down to increase and up to decrease and
retest.

CHANGING THE DIAPHRAM:

1. Install Winco part # 98574-700 (diaphragm) in the fuel mixer.

CHANGING THE TIMING:

1. On the GM 5.7 Liter engine you will have to change the timing advance
degrees from 36° to 26°.

RESETTING THE AIR TO FUEL MIXTURE

1. Once all the above steps have been completed the last item will be to
adjust the air to fuel mixture. This mixture adjustment is located on the
fuel mixer. You will need a 7/16 open end wrench to adjust it. The adjust