Parents just got a 1996 Winnebago Vectra. Using the starter switch on the generator, the starter revs very high but no attempt to turnover or start. It is an Onan 7000 with 1800 rpm 6.8 kW. Fuses look good. Any suggestions on where to start?

Are you priming before trying to start? The start switch is a rocker type. Press the bottom and hold in for 15-20 seconds, then try starting.Be sure there is over 1/4 tank of gas in the RV or it will not start. It is a safety feature that will not let the genny drain all the gas.

brisath wrote:Using the starter switch on the generator, the starter revs very high but no attempt to turnover or start.Are you saying the starter runs but does not engage the engine?

Your starter probably looks something like thisAnd if so it has a cheap plastic drive on it. From your words, it sounds like you are hearing only the starter spinning up. Correct? NOT the sound of the whole generator being cranked but not starting. Correct?If I'm right in my understanding you have a good starter with a bad drive. But, on some of these ONANs, if you can jog the flywheel a little, a blocked or stuck drive may release and operate again.That pic is from Amazon. I'm not sure the pic represents your starter. Somebody here can help you get to a service manual and a parts list. That said, the starters for several ONAN models seem to run between $35 and $55 on Amazon. If your generator design and installation allow changing the starter with the genset still in the coach, I'd replace starter with new. That's if I understand your symptoms.

Thanks for the helpful replies. Gas tank near full, and the switch doesn't toggle to prime from what I can tell. J-D's suggestion seems to be the case, as it is spinning wildly (by the sound of it) and nothing seems to engage. I think I've found the starter on the back side of the generator where it is too hard to take off without dropping or maybe swinging(?) the generator down so I'll try that in the morning and take the starter off to look at the gears. We seem to have found a rebuild assembly from the Onan dealer for $50.

Those gear drives have a roll pin in it and kind of hard to take out and put in. Turn your flywheel by hand and see how hard it is to turn if its to hard to turn the gear drive just slips its a trait of that starter I have the same gen. It has no prime. Bgm and nhm service manual

Onan Marquis 7000 Generator Starter Revs But No Action

j-d
Explorer II
Aug 05, 2013
Indeed!
Kpackpackkelley
Explorer II
Aug 04, 2013
Great news.
brisath
Explorer
Aug 04, 2013
Got 110v working. The breaker switch on the right side of the generator had flipped. Everything seems to work good now. Thanks for all the help and troubleshooting here. The new starter with good batteries fired it up.
brisath
Explorer
Aug 04, 2013
Got it running! Pulled spark plugs and confirmed the flywheel does spin easily without them in. Got it all back together and the generator started. The problem was that the auxiliary battery on/off switch on the dash had been off and even though I had tried to turn it on earlier, the switch is having problems so it wasn't actually turning house batteries on. Once I got the auxiliary power switch to turn on, the power from the 2 new house batteries started it up.

HOWEVER, the generator is not powering any of he 110 volt equipment right now, just everything on the DC. I'm not finding any breaker problems 110 volt equipment works fine on shore power, but not working on generator power.
brisath
Explorer
Aug 02, 2013
I've figured out the 12v house battery power problem, as it was the AUX POWER toggle switch on the dash that was not engaging very well. Some more rigorous pushing of the button got the house power back on. Right now I'm looking for help with that flywheel and getting the new starter to move it. There aren't many generator service technicians in my area and no one knows of one at the RV places so I might have to go a ways to find help. Boise or Tri Cities (Washington) might be the closest help for where I live. If anyone has recommendations for this area please pass it on.
brisath
Explorer
Jul 28, 2013
I'll see what I can do to find someone to do the internal work. Now my problem is tthst all of the house power I gone and I just put new batteries in. Maybe this is related to the starter but right now no house power.
Kpackpackkelley
Explorer II
Jul 27, 2013
Some really good manuals here too.
http://www.classicwinnebagos.com/Pages_HTML/FreeManuals/IFRAMEFreeManualsPg4.html
Kpackpackkelley
Explorer II
Jul 27, 2013
I'm a member here.
http://www.smokstak.com/
These are the old retired onan and generator techs. They share manuals and info. Its a great site. Come on over youll learn a lot about rv gens and home stand by gens. Pm me with your email address and tell me which manuals you need and I'll send them to you.
http://www.smokstak.com/
j-d
Explorer II
Jul 27, 2013
PackPack, you're the in-depth guy here. I'm only trying to stay afloat on the surface. 'Specially if you've got that genset, the manual, and have worked on it.

How'd you get access to the ONAN manuals, parts lists etc. I see links to CumminsOnan, but when I go there I can't seem to get beyond consumer stuff.
Kpackpackkelley
Explorer II
Jul 27, 2013
JD can explain it a lot better than I can. I sent you a private message with my phone number. If you could find a good retired generator tech that lives close to you with some tools to decarbon the heads and set the valves and decarbon them too. That's not even counting when you get to the carburetor. .

Forum Discussion

Onan Marquis 7000 Generator Starter Revs But No Action

About Technical Issues

Related Content

ONAN MARQUIS 5500 GENERATOR

onan marquis 7000 generator /no start

Generator operation

Onan Marquis Gold 5500 LP generator - Reviews ????

Onan marquis 5500 generator