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fanblade · 06-26-2006, 07:11 PM

Have a '99 Class C Winnebago with an Onan Microlite generator. Genset has 420 hours. Ran fine since we bought last fall. Mem. weekend, ran for 3 days then just died. When first started, runs for about 5 minutes. Then it just dies. Try to start again, and it won't start. After a lot of trouble shooting, we found that once it shuts off, it has no spark from the magneto. It is a KY Spec H. Could it possibly be the capacitor on the magneto? Any help would be greatly appreciated...

fanblade · 06-26-2006, 07:11 PM

Have a '99 Class C Winnebago with an Onan Microlite generator. Genset has 420 hours. Ran fine since we bought last fall. Mem. weekend, ran for 3 days then just died. When first started, runs for about 5 minutes. Then it just dies. Try to start again, and it won't start. After a lot of trouble shooting, we found that once it shuts off, it has no spark from the magneto. It is a KY Spec H. Could it possibly be the capacitor on the magneto? Any help would be greatly appreciated...

RV Wizard · 06-26-2006, 11:32 PM

fanblade, welcome to our website and forum. We are glad to have youjoin us here and look forward to reading of your adventures and experiences. The trouble with the generator could be a bad voltage regulator to loose wiring. Be sure the right oil and amount are in genset too. There is a service manual that you can purchase on this unit from Onan. Good luck and let us know the outcome. From time to time we get a couple Onan people checking the forum and they might be of more help.

fanblade · 06-27-2006, 04:35 AM

Thank you Mike and Amy. The problem seems to be heat related... We have spark to the plug when the genset is cold. After running for about 5 minutes or reaching operating tempature it quits. at this point we get no spark to the plug except when you release the starter switch it will spark once. We checked the coil and it is good, I ordered a service manual for my spec H from Onan and the one the sent only goes up to G......? You mention voltage regulator,, when it does run, we are getting system voltage to the coach. Would the VR cause it to shut the unit down? Thank you< Randy

RV Wizard · 06-27-2006, 07:53 AM

If the voltage regulator were going bad it could shut the genset down. If you think it is heat related make sure the covers are in place and that the air flow is not restricted.

Clay L · 07-02-2006, 05:29 AM

My last motor home had the same generator model.
It had a similar problem and it turned out to be associated with the oil foaming. The manual says 30 weight oil but many people use 10W 30. I bought the motor home used and didn't know what was in it. I changed to 30w and the problem went away. The foaming confused the oil level switch and it was shutting down the generator.

You can check to see if the oil level switch is involved by unplugging it and running the generator. The switch shuts the generator down by connecting a circuit to ground, so if it's causing the spark to go away unhooking it will prevent that.

fanblade · 07-03-2006, 04:14 AM

Thanks Clay on the oil tip. I have a KY spec H and it does not have the oil level switch. But that is good info to remember on the weight of the oil. after spending about ten hours all together trouble shooting..... we think it is the Mag. today,, July the third, we are taking it to a pro to change out the mag.. we will see. by the way, happy and safe fourth to all. The Wrights

Al Lyle · 07-08-2006, 04:45 PM

My Onan has 38 hours on it and have only had This RV for a Couple of months and getting ready to take trip to Penn. next month and was checking it out and generator will run about a hour then makes all kind of Rattling sound an shuts down,have checked oil level and air flow looks clean,I don't know what to do and the dealer had as is where is on paper work,I did hear it run but not long. AL Lyle

RV Wizard · 07-09-2006, 01:08 AM

Al Lyle, welcome to iRV2.com. We are glad to have you join us here and look forward to reading of your adventures and experiences. I do not quite understand what you are saying about the dealer and the genset. If it is in warranty, have the generator checked out as it could be serious. Good luck and enjoy the website.