Generac GT-990 — Reconfiguring the Fuel System from NG to LP
Installation · Demand (twin) regulator
For the Generac GT-990, from the Generac owner's manual.
Applies to: Generac GT-990 engine
Before you start
- Gaseous fuels such as natural gas and LP gas are highly explosive; no leakage is permitted.
Procedure
- Turn the main gas supply off.
- Remove the carburetor fuel hose and brass hose fitting from the NG (right) outlet port.
- Remove the pipe plug from the LP (left) outlet port.
- Install the brass hose fitting in the LP (left) outlet port.
- Install the pipe plug in the NG (right) outlet port.
- Connect the carburetor fuel hose to the LP (left) outlet port.
- Reverse the procedure to convert back to natural gas.
Specs & values
- Required natural gas pressure 5-7 inches water column
- Required LP vapor pressure 10-12 Amazon eBay FridayParts $169.30 inches water column
Source: Generac owner's manual. Steps and values are as documented; always cross-check against the official manual and any later revisions for your exact serial number before servicing.