Onan Generator Problem Update

I had already installed new points (it needed it anyway) and condensor and cleaned the almost new plugs cuz she was loping and wouldnt hold a steady RPM like all my other Onans, regardless of any carb settings. That didnt cure it, so today I disassembled the carb completely including removal and cleaning of the center main nozze and all its lil holes plus removal and cleaning under its threaded drill plugs and there were some particles in the nozzle area and a tiny bit of crud in the bowl which a good cleaning sure fixed and it was needed anyway.

HOWEVER, that still didnt cure it BUTTTTT TTTTT with the air breather off to better observe the problem (and no carb setting could cure it) I now believe I have a sticking, but not burned, valve and heres why.

When shes cutting out, prior to the governor opening up and then runnign good a while till it cuts out again, there seems to be reverse back pressure and gas pushign OUT the carb as opposed to it sucking INNNNN N as its supposed to. Its had the oil changed to Castrol and that didnt help, but Im thinking it has an intake valve stem sticking/hanging, which isnt otherwise bad or burned, cuz then it would never run good and always have a reverse back pressure spitting out the carb. She never smokes and starts well and runs smooth UNTILLLLL the cut out cycles at which (the only) time the back pressure and gas spititgn out the carb happens.

I feel like runnign some auto tranny fluid and/or that stickign valve treatment in with the oil and load her well and let the *&^%$ thing run a while.

You guys think it is a sticking/hanging intake valve stem????? and might auto tranny fluid or sticky valve stuff help????? ?

I knowwwww w this is a tractor site but I gotta have this fixed to take it to the New York Expo cuz my first wife (I call her) and daughter and her best friend are going and I dont want a bunch of women folk *&^%$ at me lol lol

John T Nordhoff in Indiana

HOWEVER, being an ignition kinda guy, I decided to troubleshoot her some more since the plugs keep coming out flat black sooty coated (too much gas). The coils primary gets its ground by a single set of points and condensor like normal, but it has 2 plug towers out top, 1 for each cylinder DUH. Im not sure how they fire, it must fire each plug at TDC on power and compression both like our Deeres with Wico mags I guess?????

Anywho, I discovered one of the coil towers produces a decent spark, while the other one is barely a visible spark at all. Sooooo ooo since an Onan double tower coil is like $100, I may tinker tomorrow with 2 coils and see what I can come up with. I think I will run them in parallell so both go to the single set of points for the ground and fire, but I may add a ballast in series, since the 2 coils in parallel would cause the points to draw twice what they are designed for.

I agree the valves can have carboned up stems (those gens set all year and run in summer is murder on them and varnish and carbon builds up grrrrr rrrr), or bad springs, or be mis adjusted (Im gonna look at all that) and thats what I suspected this morning, but Im gonna repair the bad coil problem next cuz the 1 tower with a weak spark cant be helpign things and can be why Im gettign all that raw unburned gas fouling my plugs and shes not running worh a *&&^%$

Tahnks again to all Ol John T

Hope this helps, Charlie

I think they run too hot, and that is a lot of the problem. I've noticed those gen. sets that run 1/2 speed (1,800rpm) seem to last a lot longer.

I'd be looking hard at the carb and the valves, as they seem to be weak points in those engines. Ours would throws those back fireing and lopeing fits too!! There are oil additives that are supose to fix sticking valves, but i've never tried them.

BTW, i think the starters were something like $300.00 each!!!

Robert