Dual fuel generator won't start on propane? Check these first

Try these first

1. Unplug everything from the generator.
2. Open the valve on the propane tank fully.
3. Turn the generator's propane fuel valve or fuel selector to propane (LPG).
4. Set the choke to the propane position in your manual. It's often different from gas.
5. Check the oil on level ground. The low-oil shutdown works on propane too.
6. Try a different, known-full tank.

A valve or selector is off

Symptom: It cranks but never fires on propane, yet starts fine on gas.

Why it happens: Propane has to pass two valves: the one on the tank, and the one on the generator. Champion's starting steps for propane are: "Fully open the LPG cylinder fuel knob," then turn the LPG fuel valve to ON, then the ignition switch.

Also, the regulator only lets gas through when the engine pulls on it. Champion explains that its regulator's diaphragm "opens only when the engine is in operation or starting because of the vacuum this creates." So you won't hear gas flow until you crank.

How to check and fix it:

1. Open the tank valve all the way.
2. Set the generator's fuel selector or LPG valve to propane.
3. Set the engine switch to ON.
4. Crank it.

The choke is set for gasoline

Symptom: It sputters, or fires once, then stops.

Why it happens: The choke steps for propane can differ from the steps for gas. On one Champion dual fuel model, a cold electric start uses 100% choke on gas but 75% choke on propane. A propane recoil start uses 100% choke with a "pull-to-prime" step, then moves the choke to RUN. Champion also warns that too much choke fouls the spark plug and floods the engine.

How to check and fix it (Champion's steps; check your own manual):

1. Set the choke to the propane position your manual gives.
2. On a recoil start, pull slowly until you feel resistance, then pull fast. Champion does this with full choke one or two times, until you feel a few combustion pulses.
3. Move the choke to RUN and pull again.
4. If it doesn't start in one pull on RUN, go back to full choke and repeat the priming pulls.
5. On electric start, hold the switch for no more than 5 seconds. Wait 10 seconds between tries, as Champion's manual says, to protect the starter.

The hose isn't connected right, or it leaks

Symptom: No start, or you smell gas.

Why it happens: A loose fitting lets air in and gas out. Champion says to tighten the hose onto the generator with a wrench, hand-tighten it onto the tank, and not to use tape or sealant on the LPG connection.

How to check and fix it:

1. Turn the tank valve off.
2. Check both ends of the hose are fully seated.
3. Turn the tank on. Spray soapy water on every fitting. Champion says bubbles that appear or grow mean a leak.
4. If a fitting leaks, turn the gas off, tighten it, and test again.
5. If it still leaks, or the leak isn't at a fitting, stop. Champion says not to use the generator and to contact customer service.
6. Keep the hose free of sharp bends and kinks.

If you smell a strong gas odor, close the tank valve and keep flames and sparks away. Never check for leaks with a match or lighter.

The tank is empty, new or out of date

Symptom: Everything is set right, but it won't fire.

Why it happens: Tanks run out without warning, and some aren't ready to use. Champion's manual says:

• Use standard 20 or 30 lb tanks with an OPD (overfilling prevention device) valve.
• Check the tank's requalification date hasn't expired.
• New tanks must be purged of air and moisture before filling. A propane supplier does this. Tanks from an exchange should already be purged.

How to fix it: Try a tank you know is full and in date. If a brand-new tank won't work but an exchange tank does, have the new one purged by a supplier.

Cold weather or a frosted tank

Symptom: It's hard to start in cold weather, or it starts and then loses power as frost forms on the tank.

Why it happens: Propane has to boil off into gas inside the tank. Champion explains that when a tank gets very cold, propane vaporizes more slowly and may not supply enough fuel. Frost on tanks and regulators is common. Champion says it's normally not a problem unless performance drops at the same time. It also gives different choke steps for starting on propane below 59°F.

How to fix it (Champion's suggestions):

1. Use the cold-weather choke setting from your manual.
2. Swap in a second tank and let the first one warm up.
3. Place the tank where the engine's cooling air blows out, near the handle end. Keep it away from the muffler outlet.
4. Warm the tank by pouring warm water over the top of it.

Never heat a propane tank with a flame or heater.

It's not the propane at all

Symptom: It also won't start on gas.

Why it happens: Champion's troubleshooting table lists the same causes for both fuels: low oil, a faulty spark plug, a loose plug wire, or a load plugged in at start-up.

How to fix it: Work through our main generator won't start guide.

When to stop and call a pro

Stop and get help if:

• You smell gas and can't find or fix the leak at a fitting.
• The regulator or hose is cracked, damaged or leaking. Champion says never to use a damaged fuel item.
• It runs on gas but still won't run on propane after all the checks above.

Always turn the propane tank valve off when you're done. Champion says you shouldn't leave the system open and rely only on the regulator.

Run it outdoors only, 20+ feet from the house: generator carbon monoxide safety.