Propane Generator suddenly misfiring

[RBAJJK]

Team,

Ok, I have an Onan Propane Generator, 6KW I believe. Anyway, we just got back from a trip this week to Flagler Beach, FL - just South of St Augustine (East Coast of FL) - State RV Park right on the beach (highly recommended). Anyway, dash A/C has been out for a while. We travelled 4.5 hrs there using the generator so we had A/C - no problem. We travelled 4.5 hrs back using the generator (a week later) - no problem.

However a day later (today), I finished de-sanding the RV and general clean up. Went to take it back to its storage spot, started the engine and the generator - as I did earlier. The generator starting but then started these loud popping noises.... backfiring (I think). It would run but pop loudly two to three times a second, then run smooth for 5 seconds or so (it was internittent). It would never accept a load on the engine strong enough to put out any power. As I inspected the engine, when it would make this pop, I would feel air coming out from the air filter intake.

I did change the plugs and oil a couple of weeks ago. So I know it has plenty of oil and new plugs. I have not yet pulled the plugs to see if they are fouled so much to impact firing, but like I said ran like a dream yesterday for almost 5 hours.

Any ideas??????????????

Any suggestions on where I can get good info on troubleshooting. By the way this is a 1996 Gulfstream Scenic Cruiser with the generator only having about 450 hrs on it.

Thanks as always.

Brian Kelly
__________________
Brian
1996 Gulfstream Scenic Cruiser 36' Class A
Spartan Alpine Chassis - Owned since 2006

[RBAJJK]

Sorry readers, this is actually a Generac NP-66G, not Onan....................duh!

[wagon217]

This started after you installed the new spark plugs? If that is the case I would guess you have somehow got spark plug wires crossed up causing the engine to fire out of sequence.

[RBAJJK]

W,

Thanks for the reply. Actually only 2 cylinders and given the lengths of the wires, impossible to cross. This issue may lie somewhere in the fuel supply system. As the engine asks for more fuel (higher draw for power) the issue gets much worse immediately. I haven't had much time to look into it, but thinking either the fuel regulator (or a breather tube associated with it), or simething with the auto choke, maybe even a broken spring.

Right now just too darn hot to spend alot of time working on it.

Thanks again for the response - keep 'em coming team.

Brian