Community Forums

Darrell & Mel · 11-11-2007, 05:37 PM

I have a 5K Emerald Plus Onan generator on my coach. It runs fine with when the coach is not in motion. I can run it for an hour or more no problem sitting in my driveway or campsite. However, when the coach is moving down the road and I have the generator running, it will only run for about 18 - 20 minutes and then it will die. It happens every time when I turn the generator on while driving down the road, and always runs for about 18 minutes then dies. Right before it dies, it cycles up and down about three times. I usually have the front AC unit running when this happens. Has anyone experienced this or have an idea why this might be happening? I have checked oil levels, have more than 1/4 of gas, etc. and it still happens. Thanks.

Darrell & Mel · 11-11-2007, 05:37 PM

I have a 5K Emerald Plus Onan generator on my coach. It runs fine with when the coach is not in motion. I can run it for an hour or more no problem sitting in my driveway or campsite. However, when the coach is moving down the road and I have the generator running, it will only run for about 18 - 20 minutes and then it will die. It happens every time when I turn the generator on while driving down the road, and always runs for about 18 minutes then dies. Right before it dies, it cycles up and down about three times. I usually have the front AC unit running when this happens. Has anyone experienced this or have an idea why this might be happening? I have checked oil levels, have more than 1/4 of gas, etc. and it still happens. Thanks.

RV Wizard · 11-12-2007, 01:20 AM

How many hours are on the genset? have you owned it from new? have you ran it every month for 2 hours and a 50% load on it? You may have a problem with the fuel delivery. Could be a sticking float in the carberator. You might try runing some carb and fuel injector cleaner in the fuel to see if it cleans things up. Good luck and keep us posted.

Darrell & Mel · 11-12-2007, 10:49 AM

There are 410.7 hours on the genset. I have only owned the RV for about 6 months now, and I have not run it every month. Also, it sat in the former owner's driveway for at least 6 months without even being started...when I purchased the RV and went to drive it away from FL to my ome in MD, the battery was dead, which tells me the coach just sat without being started for a while.

abarkl · 11-12-2007, 04:51 PM

I have almost the exact same issue with an '01 Marquis Gold. It only started this past summer after almost 3 years of flawless operation.
It was a very hot year here in Phoenix and it didn't act-up the same way once I made it to higher, cooler ground.
I thought I found the problem when I noticed the primary fuel filter leaking at the screw end. I had replaced it last year under routine maintenance but I couldn't get it to stop leaking.
I replaced it once again a few weeks later and no leak, but the problem was still there with the same surging then shutdown cycle.
I'm thinking it could be the "rear" spark plug that I didn't even know existed until reading another post in this forum. I still need to get it replaced for peace of mind and to keep everything within the same schedule.
I wish I had the answer you came here for and the answer to mine, but I wrote it off as extreme heat this year and don't think it will be a problem I can replicate again until next summer.

TandW · 11-12-2007, 05:05 PM

If it starts, keeps running and can power an air conditioner that is good. If it's suddenly hunting up and down it sounds like the plugs and air filter need service. Although Onan has a cylinder cleaner available for removing carbon deposits you can do this instead; remove the plug wires and crank the generator for ten seconds. After five minutes crank it again for ten seconds. This procedure thoroughly wets the cylinders with, you guessed it, detergent gasoline. Do your plug and filter maintenance, start it up with no load and stand away from the exhaust as the carbon comes out. Let it warm up a little and put a heavy load on it. You want to get the carb open with a good heavy load, right now. Half load doesn't get the carbon out. Ten minutes or so with a good load should clear it out. Thereafter subject your genset to a good heavy load perioically to keep those cylinders from choking up on carbon. Good luck!!