My 345's generator bagan to run poorly recently.  It would burp, belch and shudder.   I found that the original rubber gas line had cracks in it allowing it to suck air.
Six feet of gas line, a clear fuel filter, a set of spark plugs and four clamps later, she purrs again.

That's good to know. I'm chasing an intermittant shut down on mine. Coop sent me the operator manual and I hope to post it on the site soon. I installed a clear fule filter a couple of years ago when I was troublshooting other issue with the Onan. It's great to "see" if fuel is moving. Added one to my Beetle's 1600 as well - same reason.

Since we have the diesel our Genset runs on Propane.  I had two problems that we chased for a while.  The first was a loose screw on the back of the carburator that allowed air in and made it run rough.  As it warmed up it expanded and got worse.  A tech finally found it with a dental mirror and tightened it.  The second confounded us until we checked the points and found that they had slipped waaay out of adjustment.  Reset them and it works great again.

Got your Genset running right yet Steve?  An Onan tech told me that the usual cause of surging is the governor spring losing its strength.  They recommend replacing the spring periodically and then tuning the engine.

I haven't had any time to work on it much. The idea of the return spring makes a ton of sense. I plan to visit the Onan store soon and pick up a new spring. The tuning procedure looks pretty basic so I'll tackle this all at once.

While at the Onan store pick up a tune up kit.  Includes plugs, points and such.  You'll probably need a dental mirror to set the points along with allan wrenches.

Look closely the rubber gas line.  Yours is probably as old as mine was which was my problem.  

JK,
Good suggestion. While I haven't had the time to get into the generator since Coop sent me the manuals, I did fire it up the other day from the compartment switch and just "watched" how it ran and died. It seems like fuel starvation or plug fouling. But since it restarts every time and the plugs look good...I'm now thinking fuel.

I'll run a test line into a gerry jug and see if I can improve the situtation with clean, new fuel lines.

I'm not terribly bright sometimes. I took the day off to work on the 345. One of the things I wanted to address was the generator cutting out. I had replaced the fuel lines earlier but it didn't make any difference. It seemed like I could start it and it would run for about ten maybe twenty seconds the shut off. Not sputter or die or "load up"...just turn off.

I tested the fuel pump adn checked a few connections for voltage. Everything seemed fine. Just for fun I checked the oil level (since I was headed to Camping World anyway today I thought I might need to pick up some Onan oil). Gues what...it was at the low mark.

So, the low oil cutoff switch was working. It is designed to allow the engine to start, but then shut off the ignition in a low oil situation. Sure enough, one quart later....it ran for three hours straight.

we have a 6.5 "P" onan. when we picked up the MH it ran fine. less than an hour later, it was sputtering and shuttuing down. pulled the plugs and they were very dirty from running way to rich. no one in our area stocks them so they should be in later this week. system has clicked 43hrs. since last tune-up/oil change........2-1/2 yrs. ago!

cleaned the plugs as best we could and could get it started, but it immediately started hunting, tripped the surge circuit breakers, strong smell of gas and shut down.

suspect we will find a stuck float. like the idea of replacing the fuel line and installing a clear filter....hadn't even thought of that.

will let you know when we get it going.

we are finely about ready to tackle redoing the genset. the parts came in and are just waiting for us.

we would also like to replace the supply line. it "disappears" above the fuel tank. do we need to drop the tank some to reach the other end? does it "re-appear" somewhere else that we are not finding?

thanks

Pretty sure it does run up the the top of the tank. I replaced as much of my rubber fuel lines as possible on mine, but stopped short of dropping the tank.