| [GMCnet] Onan Saga [message #181417] |
Thu, 23 August 2012 10:40  |
Gary Bovee
Messages: 177
Registered: August 2008
Karma:
|
Senior Member |
|
|
GMCers,
My Onan had not been running well for about the last year. I normally don’t use it much and kept putting off trying to figure out what was wrong with it. Well that came back to bite me.
I had installed new plugs a while back so I knew that was not the problem. I had recently checked the fuel filter and the screen in the fuel bowl to make sure they were clean and they both were. I tried adjusting the carb main fuel adjustment screw and the rubber o’ring on the adjusting screw fell apart. I got a rebuild carb kit and rebuilt the carb. Fired up the engine and it still did not want to run smoothly. It was running a little rich. I pulled the carb and rechecked the float setting to made sure it was not hanging up. When I went to put the fuel bowl back on the rubber o’ring that fits on the fuel bowl had swollen up about an inch too big and could not put the bowl back on. I just love the gas we have now and what it does to rubber parts. I ordered a rebuilt carb from JimK and put it on. Fired up the Onan and it ran so rich there was this large black cloud coming out of my shop in no time. Called Jim and he sent me another one (no hassle to get him to replace it). Thanks JimK! The next carb didn’t cause any smoking, but the engine still sounded like it had a slight miss and adjusting the carb did not make a difference.
My wife and I decided to take a trip to Oregon. The day we left it hit 110 degrees in Red Bluff and on our way north we needed to use our roof a/c. Well the further north we got the worse the Onan run. My wife got a lot of exercise that day. Every time the Onan would start running rough and slowing down the roof a/c would kit off. Then she would have to go turn it back on. We made it to Gene Fisher’s place in Oregon, but by then the Onan was really running rough. Gene took me to every parts house around there to try and buy a set of points and condenser for the Onan, but of course no where could they be found. I tried filing the points and set the timing. Still ran rough. So we decided to try some other things. Gene was nice of enough to drive me over to Jerry Wheeler’s place and Jerry loaned me a Harley coil. (Thanks again Jerry for letting me borrow the coil). Unfortunately that did not help. Gene had a new electric fuel pump so we thought what the heck lets try that too. Still no luck. The more we ran the Onan the worse it got.
My wife and I ended up taking two days to get back home only diving in the mornings because it was too hot in the coach with only one roof a/c to try driving in the afternoons.
When I got back home I installed a new set of points and condenser. WOW!!! The Onan ran like new. Just as smooth as could be at idle or under load. I had read in the Onan manual that the points should be checked after 100 hours. Mine has 430 hours and were probably the original set. Lessen learned.
Moral of the story – Do a standard tune-up (points, condenser & plugs) and set the timing, before you spend hours fiddling around wasting time doing unnecessary stuff.
Also, If your Onan carb main fuel adjusting screw o’ring has never been changed there is a good chance it is leaking especially if you tried adjusting it. As soon as you start turning it it may start crumbling a part and therefore start leaking. Thanks Emery, I learned from an earlier post of yours to check the o’ring.
Now that it runs great I am feeling really daring. I going to install an electronic ignition in the Onan in a couple of weeks.
Gary Bovee
1978 Royale by Coachmen
Red Bluff, CA
Idiot's Internet Guide to Finding 1973-1978 GMC Motorhome Information
Wireless Air Systems, Alternator & A/C Belt Tensioner Adjustors
Headlight & Turn Signal Reminder Alarms
http://www.gmcidiotsguide.com
_______________________________________________
GMCnet mailing list
Unsubscribe or Change List Options:
http://temp.gmcnet.org/cgi-bin/mailman/listinfo/gmclist
|
|
|
|
GMCforum
Search
Help
Register
Login
Home
