Onan Marquis 7000 Generator Starter Revs But No Action

[brisath]

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?

[j-d]

Indeed!

[Kpackpackkelley]

Great news.

[brisath]

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]

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]

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]

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]

Some really good manuals here too.
http://www.classicwinnebagos.com/Pages_HTML/FreeManuals/IFRAMEFreeManualsPg4.html

[Kpackpackkelley]

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]

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]

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. .

[j-d]

With the spark plugs removed, it should roll smoothly through every revolution. If the plugs are still IN, then you're feeling the cylinders coming up on their compression strokes and that's normal.
Try what PackPack suggests. Pull the plugs and check to see that it rolls smoothly. Then install Starter and try to Start it. Starter should engage and genset should rotate smoothly. Then roll it again by hand. There shouldn't be any resistance from the Starter. You'll know the starter's releasing and there's no interference.
It could be the genset happened to be shut down with a piston exactly at Dead Center. Where it stops going Up and hasn't started going Down. If the genset than sat that way a long time, the piston could have gotten sticky in that position. They're much harder to crank than when piston happened is part way.

[Kpackpackkelley]

That sounds good. You may have to set the valves. But for right now pull both spark plugs out and then try to start it. It won't start but see if it will spin the motor . That will tell us about the valves. Are you sure your getting the full 12 volts to the starter when you are trying to start it.

[brisath]

I did have the cover off at one point and was spinning the blower wheel and it wasn't spinning that freely. It had very difficult places throughout a revolution that required some effort to push through. How easily should it spin? I do have the manual as downloaded from the link in the previous post. Thanks for all the help so far.

[Kpackpackkelley]

I'm calling the blower wheel the flywheel I'm sorry. Once you take you top cover off you can turn the blower wheel by hand or put a socket on the bolt . Then we will know if the piston is stuck or the valves are stuck or need adjusting you may also check your bearing on the other end may need some oil or grease in it. Do you have the parts manual ?