Generator problems

Sorry for the long post, but want you to have the full picture. We recently bought a 2008 Cyclone 3912. Dealer (not a Cyclone/Heartland) dealer told us the rig was Brand New, but he had picked it up from a dealer who was going out of business. It was a little dirty on inside but still had mfg. tags on the sofa so we believed him. When we picked the rig up the generator was running so figured it was good to go. After getting it home the genny wouldn't start, figured it was just low on gas added about 5 gallons and it made an attempt to start, but the gas in the bowl looked pretty bad, so I dropped the tank, flushed it out, cleaned the lines, cleaned the carb. Got it to run somewhat and after adjusting the altitude screw had it running pretty good. Ran for twenty minutes with both breakers off (no load) without missing a beat. Then swithed breakers on and ran it for another 15 min, with an ocasional miss but not bad. At that point only draw would be, microwave clock, coffee maker clock, and tv radio clocks. Then I started turning on lights from garage forward, by the time I got into bathroom and turned that light on it killed the genny. I did not notice any increase in RPM, although it seemed to be running fairly fast at idle. This happened twice. According to warranty dept. at Heartland were not the original purchasers so no warranty is in effect. Can't get it into local Onan service center until May 18 and our first trip is May 4, so will be taking the Honda 2000 along for back up, if I cant get it figured out. Any suggestions?
This is a great forum, I've allready learned a lot about our rig thats not covered in the "owners manual"
Thanks for the help
Brian
 

jimtoo

Moderator
Hi Brian,

Welcome to the Heartland Owners Forum and Family. We have a great bunch of people here with lots of information and all willing to share their knowledge if needed.

I'm sorry your having problems with your Onan, but someone will jump in here and give you some ideas or lead you to the problem.

Enjoy the forum and think about joining the Heartland Owners Club also and attending a rally.

Jim M
 

jmgratz

Original Owners Club Member
If I were in your shoes I would be talking to my dealer about the situation since you just got it home from them.
 

RollingHome

Well-known member
I agree with both Jim's. In the mean time, is there a Onan dealer near where you will be going on your May 4th trip ? They often have field service tech's which will come to the RV in the park. I had an Onan on my last boat, they can be a pain at times. As you increase the electrical load the genny will bog a little then increase rpm to match load. It sounds like your unit was not compensating for the increase in load. Honestly, it sounds more mechanical then electrical. I also would suspect the stale gas may have varnished the carb so running it with some carb cleaner (Gum Out) in it may help. If you can reach the throttle linkage safely, try to manually change the speed to see if the carb is working. If it quits the carb needs attention, clean it or rebuild it. I cost me $ 80.00 to have my carb rebuilt and the thing ran like a charm without trouble.
 

Jett

Active Member
Sounds like the emulsion tube and/or altitude compensation oriffice are partially plugged. My generator had the exact symptoms after I let it set for too long and the gas in the bowl congealed. If you're familiar with carbs you will find that this one is pretty simple and is very easy to clean. To resolve your problem you probably don't even need to remove the carb -- just drop the bowl and clean the tube and oriffice with carb cleaner.
 

PUG

Pug
I was having similar problems and figured it was old gas plugging stuff up. I pulled the carb, dismantled, soaked it and reassembled. Helped some but ending taking to to Onan (Cummins) and they would not warranty the carb. They said the carb is excluded from the warranty. Great thats $150 for a new one and they would not try to rebuild the old one. Great Great. Eventually after a new carb it still wasn't running. They ended up pulling the unit out and replaced some kind of a load gizmo that you have to pull it to fix, I guess. The warranty covered this luckily but not the carb. I now run a gas stabilizer and run the gen every three weeks for an hour.
 
Where is the emulsion tube? It does seem the altitude adjustment has a lot to doe with it, still trying to get it adjusted correctly. Is there a starting point. ie: fully closed and then open 1/4 turn, 1/2 turn?
Thanks
 

Jett

Active Member
The emulsion tube is inside the carb. When you remove what appears to be the bowl drain plug, the emulsion tube comes out. The altitude compensation adjustment should be turned all the way counter-clockwise for sea level. If the carb is clean and working properly, you shouldn't have to mess with the altitude adjustment -- unless you change altitude.

Just a note of warning: It's very possible to overheat an engine or even burn a hole in a piston when an engine is ran with a partially plugged carb. (Puts it in an excessively lean condition) I'd recommend you contact an RV dealer.
 
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