Generator runs rough

Forzatm · 03-27-2015, 04:55 PM

OK so I decided to start the generator for the first time. It had 15 hours on it when we bought it. This thing runs so rough it shakes the front nose and when I turn on AC it's seems to smooth out a little but when I turn it off it goes back to running rough. Does anybody else have this problem with their generator. It acts like it's running on 2 cylinders instead of 3. Is this normal or should I take it in for service? Will injector cleaner help?

Ranger Smith · 03-27-2015, 05:16 PM

I would run some sea foam through it.

jerichorick · 03-28-2015, 08:53 PM

Quote:

Originally Posted by Forzatm

OK so I decided to start the generator for the first time. It had 15 hours on it when we bought it. This thing runs so rough it shakes the front nose and when I turn on AC it's seems to smooth out a little but when I turn it off it goes back to running rough. Does anybody else have this problem with their generator. It acts like it's running on 2 cylinders instead of 3. Is this normal or should I take it in for service? Will injector cleaner help?

What year is your rig? Generators need to be run under load for about a half hour each month. This keeps them from having the problems you are facing now. I have many guesses but no answers. If it is several years old I would replace the fuel filter, air filter (they go bad over time) and do a oil & filter change. This can't hurt. (I use Royal Purple oil. Good stuff.) When you run it after that put as much of a load as you can on it and let it run for an hour or so. See if that gets it working again.

Onans normally run very smooth and quiet.

Rick Y

SuperGewl · 03-29-2015, 01:45 AM

Please fill out your Signature with your MH info so we may help you better.

Forzatm · 03-29-2015, 11:00 AM

Sorry about the lack of info. I have a 2014 38R Forza with a 6000 Diesel generator. I went to the dealership to complain about the generator running rough. The service manager told me I am the 5th Forza owner that has complained about the generator. He said some of the 34 and 38 models are coming in with complaints about the same thing. He told me I had to take it to the Cummins/Onan shop for service. Has anyone on this forum had their diesel generator serviced for this problem, and if so, what was the fix?

cbeierl · 03-29-2015, 11:07 AM

Quote:

Originally Posted by SuperGewl

Please fill out your Signature with your MH info so we may help you better.

Profile says the OP has a 2014 Winnebago Forza 38R.

Ray,IN · 03-29-2015, 06:32 PM

The Cummins Onan Generator RV Handbook, on page 10, states Onan RV generators should be ran at 50% load for 2 hours every 4 weeks.

jerichorick · 03-30-2015, 08:54 AM

Quote:

Originally Posted by Ray,IN

The Cummins Onan Generator RV Handbook, on page 10, states Onan RV generators should be ran at 50% load for 2 hours every 4 weeks.

I know. I have commercial experience with Onan. We used many different sizes when I was in the power department of the phone company. Ran them once a month under load for about a 1/2 hr.

On this rig we have 495.7 hrs on the Onan. Not a problem. Most of the time is real usage.

But, the OP just wants to get running again. Personally, I think he is dealing with a stuck valve. I'm hopping may post to him will get the unit hot and well lubed. The valve may free up and clean up.

Rick Y

Todd157k · 03-30-2015, 02:00 PM

Quote:

Originally Posted by Ranger Smith

I would run some sea foam through it.

+1

If it runs rough at idle, but smooths out under load, the pilot jet/air system is clogged. Run a strong mixture of Sea Foam in the fuel. Run at idle for 20 mins or so, let sit for a day, run again.. It will clear out, eventually.

jerichorick · 03-31-2015, 01:02 PM

Quote:

Originally Posted by Todd157k

+1

If it runs rough at idle, but smooths out under load, the pilot jet/air system is clogged. Run a strong mixture of Sea Foam in the fuel. Run at idle for 20 mins or so, let sit for a day, run again.. It will clear out, eventually.

Not to argue but to make certain we are on the same page, the OP has a DP and the Onan is also diesel. His fuel system is a fuel pump and rack to injectors. I don't know if Sea Foam is the answer here. Might work. A clogged injector or hung valve could be the problem. He has not indicated that he has received a trouble code. If he did get one then we would have a better idea as to where to look.

Rick Y

Ray,IN · 03-31-2015, 08:11 PM

Seafoam is made for both gasoline and diesel fuel, both work as advertised-very well. So your phone company only ran the genset 1/4 the recommended time each month, makes for job security.

Todd157k · 04-01-2015, 09:41 AM

Quote:

Originally Posted by jerichorick

Not to argue but to make certain we are on the same page, the OP has a DP and the Onan is also diesel. His fuel system is a fuel pump and rack to injectors. I don't know if Sea Foam is the answer here. Might work. A clogged injector or hung valve could be the problem. He has not indicated that he has received a trouble code. If he did get one then we would have a better idea as to where to look.

Rick Y

Yes, either.. and if it's injection, all the more so. Sticky injectors will definitely cause rough idle.

Forzatm · 04-01-2015, 12:56 PM

I have been running my generator a lot for the last two days and took the advice of running a heavy mixture of diesel injector cleaner. The coach is almost at a quarter tank of fuel. I added five more gallons of a mixture of diesel fuel and injector cleaner. I did not use Sea Foam because I never heard of it and I didn't know if it would hurt the diesel generator. Some people on this forum think I have a gas generator. It is starting to run smoother as I have been running it under load for 3 to 4 hours. It is almost to the point where the roughness is gone. I think I had an injector that was clogged because it was only running on two cylinders. What does OP mean?

cbeierl · 04-01-2015, 01:03 PM

OP stands for 'Original Poster'--i.e. the person that started the thread.

Forzatm · 04-01-2015, 01:03 PM

NO! Trouble codes

Todd157k · 04-01-2015, 03:19 PM

Great news! We were only recommending one particular brand that works very well. It is just another injector cleaner though. Sorry for the confusion but looks like it is taking care of the problem.

jerichorick · 04-01-2015, 06:00 PM

Quote:

Originally Posted by Ray,IN

Seafoam is made for both gasoline and diesel fuel, both work as advertised-very well. So your phone company only ran the genset 1/4 the recommended time each month, makes for job security.

Years of experience and proper maintenance on the part of the company. The Kuboto engine used in our RV generators is not a fluff ball. The greatest abuse is not running it at all. The 2 hr run time is to drive ALL of the moisture out of the alternator. With the between work runs, test runs plus the regular usage keeps the moisture problems at bay.

If it is built it will fail. If it is abused it will fail quicker.

Rick Y

jerichorick · 04-01-2015, 06:14 PM

Quote:

Originally Posted by Forzatm

I have been running my generator a lot for the last two days and took the advice of running a heavy mixture of diesel injector cleaner. The coach is almost at a quarter tank of fuel. I added five more gallons of a mixture of diesel fuel and injector cleaner. I did not use Sea Foam because I never heard of it and I didn't know if it would hurt the diesel generator. Some people on this forum think I have a gas generator. It is starting to run smoother as I have been running it under load for 3 to 4 hours. It is almost to the point where the roughness is gone. I think I had an injector that was clogged because it was only running on two cylinders. What does OP mean?

Good for you!

That is a fix that anyone can afford. I hope you continue to use you generator more often. If you don't have a DEF system for your coach engine you might try running 2 cycle motor oil in your fuel. On my last coach I used 1 oz per gal of the cheap Walmart stuff. Search the net about this topic. It is not the greatest top end lube but it is the most economical and it works.

Happy trails,
Rick Y

jondrew · 04-01-2015, 08:08 PM

Quote:

Originally Posted by Forzatm

Sorry about the lack of info. I have a 2014 38R Forza with a 6000 Diesel generator. I went to the dealership to complain about the generator running rough. The service manager told me I am the 5th Forza owner that has complained about the generator. He said some of the 34 and 38 models are coming in with complaints about the same thing. He told me I had to take it to the Cummins/Onan shop for service. Has anyone on this forum had their diesel generator serviced for this problem, and if so, what was the fix?

We probably have the same generator. Mine ran fine, but it did smoke quite a bit. I took it to my local Cummins shop and they said it needed to be broken in. Run it at greater than 50% load for 7 or 8 hours. I did that and it seems to run fine now. It does seem to run a bit rough(er) when the load is off, but not terribly. I try to run it at least twice a month for an hour under load. They don't like to sit around not being used.