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Wheelman1959 · 10-18-2021, 11:30 PM

I recently recevied a 1995 holiday rambler from someone who passed away and am slowely fixxing it back up here's my problem the genset will not start i have new batteriesfor the coachand new fuses in the genset it is a onan marquis 7000 gas
Any help would be greatly apprecated

153stars · 10-18-2021, 11:39 PM

So does it crank over.?
Most gas gen problems are fuel pump or gunked up carb. Also most genny won't run if under or near 1/4 tank.

jacwjames · 10-19-2021, 08:00 AM

If the generator has not been started for a while the carburetor may be gummed up. Doesn't take long for the gasoline to turn to varnish.

You may have to remove the carb and go through it, completely clean, pull the needle valve and float from the bowl. Make sure it it passing fuel.
Seafoam goes a long way fixing this type of problem.

tap4154 · 10-19-2021, 10:39 AM

As I mentioned in another thread yesterday,, I fixed my parents Onan Marquis simply by opening up the carburetor drain and spraying Onan 4C up in there, letting it sit for a day, draining it and doing the same thing again. The RV shop said they needed a new carburetor, but it worked beautifully after I cleaned it without even removing the bowl. It's worth a try. If you can't find "4C", which is discontinued, try Seafoam. Get the spray version so you can stick the straw up the carburetor drain hole. Then once you get it running, make sure to run it on occasion, so it doesn't get gunked up again. Or some people put a shut off on the fuel line, then let it run dry.

Wheelman1959 · 10-20-2021, 01:06 AM

Quote:

Originally Posted by 153stars

So does it crank over.?
Most gas gen problems are fuel pump or gunked up carb. Also most genny won't run if under or near 1/4 tank.

No i can't get it to do anything

Kenrbass · 10-20-2021, 06:27 AM

There should be switches on the dash and at the genny. If neither work, check for fuses near the control panel at the genny. If it cranked and won't run, then the carb, and fuel make sense.

tap4154 · 10-20-2021, 08:56 AM

If not cranking you need to start looking at all the electrical connections at the generator starting solenoid, the ground connection and the switches. If it's been sitting for a long time, once you get it cranking you're probably going to find you have carburetor problems.

153stars · 10-20-2021, 08:58 AM

EDUT Me and above were typing at same time. I also agree to be prepared to clean the carb.
I don't know your genny very well but it should have a starter solenoid. Some are easy to jump across the cables to engage the starter. Also listen for a click as someone tries to start it. Does it have control panel at genny try starting it there. Many heavier pos cables will have large fuses near source distribution area . These don't usually blow unless someone actually shorted the cables or they rubbed through.
Cummins has good manuals as well as service manuals online free skip any sources that try to get you to sing up . Search your Model manual add pdf at end. Flight Systems has good troubleshooting flow charts . They are a great resource for DIY owners.

donr103 · 10-20-2021, 10:39 AM

If cranking.. try starting fluid while cranking.. use all safety precautions.. and with air filter removed... if starts.. you know it's a fuel problem.. if does not.. then something else..

Carb is made to be cleaned.. it's easy and most of time.. nothing needs to be taken apart..
SO don't replace carb..
Report back to us on if it starts with starting fluid into carb.. or if just not cranking at all

Good luck and let us know what you did and maybe better members then me will help you

mr.tommy · 10-20-2021, 06:03 PM

You said it won't do anything. Well then right off the bat the battery needs to be looked at.
No telling how the previous owner maintained it and performed the regular PM items. There's a lot of things that need PM to keep them running right and be dependable along with other practices.
There's is no quick answer to your problem without digging in some, but if you want to learn how to bring this genny back up to snuff with all the PM items—which could very well be part of your problem—watch this 3 part series on YT. You'll be miles ahead of most RVer's on how to care for your Onan.
https://www.youtube.com/playlist?lis...cn1LTAzgImKgH0