Woodmizer 1992 Onan 24xl acting up

[canadianwoodworks]

We had had this mil for about a year, motor has 4800+ hours on it, the other day my brother was milling and noted that it would sometimes really start to run bad and send out a lot of smoke.  I have removed the heads and taken some pictures.

I've read and watched about adjusting the valves which I will check, just have to get a feeler gauge.

Here are some pictures, of the inside. There is a lot of carbon build up, what should I use to clean it off?

The cylinder wall on the side with the oil filter does have 2 noticeable scratches which I can feel with my fingers, the other side is very smooth all around.



  

  

  

  

  

  

 

I did find a bad exhaust gasket on the muffler and some cracks that I will be fixing also.

[deadfall]

By the carbon on those studs, looks like head gaskets were in order anyway.

[beenthere]

Likely that carboned-up sparkplug wasn't always giving a spark and caused a lot of the "run bad" and a lot of smoke. Neither plug looks good.

[canadianwoodworks]

Found gasket kit on Ebay just ordered.

How do I clean off all the carbon build up, after reading the manual is says to clean off carbon every 200 hours, I doubt this was done, if ever.

[caveman]

Simple Green, carburetor cleaner (the kind you soak a carburetor in that comes in a gallon can like Gunk does) or even oven cleaner should remove the carbon.  Some folks recommend not using oven cleaner on aluminum parts but the carb cleaner should not harm it.

I have used a brass brush to remove corrosion from aluminum outboard engine parts along with solvent so that may be an option for stubborn parts or those that may not fit into a gallon can.
Caveman

[Kbeitz]

rebuild thread....

http://www.mytractorforum.com/12-john-deere-forum/762649-onan-b43e-b43g-migration.html

[Andries]

Welcome to the FForum Canadianwoodworks.
Check out this thread: https://forestryforum.com/board/index.php/topic,76647.0.html
When my Onan started to act up, it turned out to be a coil that was breaking down and operating intermittently, as well as a few loose/missing head nuts.
Good luck with your project and parts can be found at most Cummins dealers or Woodmizer - whoever happens to be closer.

[wetdog]

Boiling hot water, Dawn dish soap, and a scrub brush.

[woodmills1]

When I had an Onan 24 I used a decarbonizing spray from a can I think I got from Woodmizer.  It worked very well and I never took the engine apart in 3600 hrs.  I also used the little bit of water through the carb trick once or twice.

[jwilly3879]

My neighbor used wild rice and water. Said the rice (not minute rice) would not hurt anything. Revved it up and started puring rice in the carb until it started to die, let it clear up and then slowly pour water in until it was ready to quit and repeat. It was amazing to see the crap coming out of the muffler.

Pulled a head off after this treatment and it was clean as could be.

[deadfall]

Wild rice: cooked or uncooked?

[canadianwoodworks]

planning on cleaning the Onan up over the weekend, found gasket sets on ebay waiting for them to show, hopefully soon.

Thank all for the tips, don't know which way I'll go with the cleaning. I will post when I do take care of it.

[Delawhere Jack]

The idle mixture screw can get out of adjustment running too rich. It will cause smoke, hard starting and a loaping idle. The screw may be hidden under what looks like a tiny freeze plug, about 5/16" dia. on the pulley side of the carb. They put the cover on to prevent tampering. Just pop it out with a chisel or scratch awl.

[Kbeitz]

The biggest problem with onans today is the new gas and the older fibered float.
Change it to brass and you will see a world of difference...