Symptoms
- Starts and runs fine on gasoline but not on propane
- Won't start at all when set to propane mode
- Runs weak or stalls on propane specifically
- Propane tank feels fine but no fuel seems to reach the engine
Likely causes
- CommonPropane tank valve not fully openA partially open valve restricts flow enough to prevent proper running.
- CommonLoose or improperly connected propane hose/regulatorA poor connection can restrict flow or let gas escape rather than reach the carburetor.
- CommonFuel selector switch not fully set to propaneMany dual-fuel units need the switch turned firmly to the propane position, not left in between.
- PossibleLow propane tank levelA nearly empty tank, especially in cold weather, may not maintain enough pressure to feed the engine reliably.
- PossiblePropane carburetor jet or regulator issueLess common, but a clogged jet specific to the propane circuit can prevent proper operation.
What to do
- Confirm the propane tank valve is fully open, not just cracked.
- Check the hose connection between the tank and generator is fully threaded and tight, listening for any hissing that would indicate a leak.
- Make sure the fuel selector switch is turned firmly and fully to the propane setting.
- Try a different, known-full propane tank to rule out a low or empty tank as the cause.
- In cold weather, propane tanks can lose pressure; keeping the tank reasonably warm (not near heat sources) can help.
- If it starts on propane but runs weak, check for a leak at the hose connections using soapy water, since even a small leak reduces delivered fuel pressure.
- If a full tank, tight connections, and correct switch setting still don't get it running well on propane, the propane-specific regulator or carburetor circuit likely needs professional service.
Tools and parts
- Wrench for hose fittings
- Soapy water for leak testing
Propane hose and regulatorSearch: “generator propane conversion hose regulator”
When to call a pro
If connections and tank level check out but propane operation still doesn't work, a small-engine shop familiar with dual-fuel systems can service the propane regulator and jet.
Safety
Use caution
Check propane connections for leaks with soapy water, not an open flame, and always work outdoors in a ventilated area.