My coach sat for nearly 20 years. While the motor and a few other things were somewhat attended to by the previous owner, many things still need lots of attention.

I have little experience with onan generators other than oil and filter changes. Having sat so long, I'm wanting to do whatever i can to get it back to reliable operating condition. Any tips? Best place to find affordable parts? I'm sure i will end up rebuilding the carburetor, full tune up etc.

Also, aren't our generators designed to slide out for easier servicing?

Thanks in advance.

On my old Euro the sled had been permanently locked in the closed position for structural reasons. On the 78 I have to remove 2 bolts that hold the sled closed, then pull out the genny. Good luck with the rest of getting it going. Billy T is the resident Onan expert but unfortunately we haven't heard a lot from him lately. Hopefully he'll see this and chime in.

Duane is currently working on his. Might be very similar. Check out his post in “Nose does it again”. Maybe he will post here when he sees it.

On my 72 the generator corner was completely rotted off. Generator was gone. No clue as to how it was mounted.

DBarth (94 Aristocrat) hade the generator mounted solid in the front. Midnight (Monarch 97) has a front slide out. Just completely rebuilt to accommodate the new to me Cummins Onan Quiet 8000 Diesel (Thanks Ed!!!!) to replace the Quiet 5500 LP that was put into replace the original Koehler 7500 that the stator went out on.They didn’t have to rebuild because the 5500 fit without any issues. I had to completely cut everything out and start over. The 8000 used every bit of available space. It is a great upgrade that now runs off my 150 gallon diesel tank.

Every Barth is unique. Wally’s Monarch his has to drop down to service. Steve’s Monarch is on a side slide. Bobs is a slide out the front like mine but was originally the diesel.

Side note I currently have my Quiet 5500 for sale. Trying to sell local so they can come pick it up.

Over the years I have worked on several Onan generators. Many had been sitting for a long time.

Number one, as you suggest, is to drain and clean the fuel system. This almost always much of the problem.

We have had several that had compression issues. This was usually the result of rusted/stuck valves. We could usually get them moving with a bit of lube. On some we pulled the head and lapped the rust off the valve seats with valve grinding compound.

A few more had ignition issues, usually burned and sticky points. Good tuneup and away you go.

Sadly, the cicuit boards on these are often subject to failure. They are not repairable and many are no longer being made. I have seen several Onan generators that ran well but had to be retired due to circuit board failure. When boards are available they always seem to be over $250. We never had much luck getting circuit diagrams and schematics for them either. Search the model on the web, you might get lucky.

Good luck with these dinosaurs.

Drew, my gen was running just fine I was using it during our week long power outage to power the house. First there was a pop or two then it just started to run popping and missing, shut it down and it did not restart.

So took the carb off, cleaned it, pretty easy job, but lost the float spring. Now discovered there is not even any spark, ordered new point set and found a similar carb all on Ebay. Not to expensive either. Saw a way to check the coil about 4 to 6 ohms across the + and - terminals and 15k ohms between the left and right plug wire terminals.

My worry is the circuit board is not working as it should. Check the fuel pump too, maybe run some fresh gas through it. Of course new oil and filter too.

Nose does have a in/out slide, there are two bolts, holding it in place one on either side of the tray.

On my "Nose does it again" post page 9 or 10 is a link to a diagram and function write up for this GenSet.

After you get the engine running, checking your generator part is a whole different project. Perhaps disconnecting one of the pigtails might be a good idea until you get the engine working.

I see Professor Steve just gave you good advise!! More experience that me!!!