Generator starting problem


Junior Member
I have a 2.8 Onan microlite RV generator when its cool it will start, and run until I shut it off, once I shut it off, it will re-start if done within a few minutes, but wait 15 or more minutes, and it will not start for at least a couple of hours. I have replaced the ignition coil, and the spark plug, since I do not get a constant spark when it fails to start, but, just one spark when the start button is released. I have checked the magneto voltage at the time that I am not getting a constant spark, and it reads 31 volts which is within normal range when cranking. At this time I have run out of ideas, maybe someone out there has had a similar problem and can help me.

Nicole Rushing

New Member
There are about 4 possibilities. Bad circuit board, bad voltage regulator, dirty slip rings, or low oil pressure/or bad oil pressure sending unit. Probably the most common no-start problems are fuel supply, so change the inline fuel filter and make sure fuel flows freely. Cracked fuel lines are a common problem too, allowing the genny to suck air along with fuel.


Junior Member
Well it seems that non of those 4 possibilities is the culprit, since I have already replaced those parts with the exception of the voltage regulator, which I have no problem the voltage and frequency is constant no matter what the load. Parts replaced: control board, ignition coil, spark plug, fuel filter, and air filter. and the problem has not changed one bit. So I think is time to bring in the experts.


Junior Member
Just to update everyone that read the original post. The problem was the magneto, even though I was told that if I was getting between 15 and 50 volt A/C the magneto was good, well if was not. Replaced it, and it runs and starts, just like when it was brand new.
Live and learn.


Banned Users
One tip I've learned over the years is to make sure to exercise the generator at least once a month especially when your RV is just sitting for a while. I use a great program on my computer called Automotive Wolf vehicle maintenance software to track all the maintenance on my RV including the generator. Basically I run the generator once a month for about 45 minutes with no load and then 15 minutes with the AC on high. Ever since I've been doing this I have not had any issues with my generator. Letting it sit for an extended time without running it will cause problems.