How do you adjust the valves on a Onan G24?

Joanie · September 16, 2012, 07:22:45 AM

I understand get the valve to the closed position. What do they adjust to?

Okrafarmer · September 16, 2012, 08:56:43 AM

I'll be watching for answers, too, as we may need to do this soon. . . . ;D

Jim_Rogers · September 16, 2012, 09:07:22 AM

I wrote down the gaps on the valve linkage when you adjust them. I was told as the engine gets older the valves wear and get tighter. You have to open them up more when you adjust them. I believe that's the way it goes.

The intake should be at .005 and the exhaust at .013

And I believe you are right about the values needing to be seated when you make these adjustments.

Also, you have to remove the exhaust to access the covers to remove them to you can get at the valve adjusting bolts.

So you may need a set of exhaust and intake gaskets on hand when you take it all apart.

I think my mechanic used a piece of wire to reach in through the spark plug hole to feel the piston to figure out when it was at the top of it's stroke so that all the valves to that side were closed.

I'm sure if I have this wrong someone else will post the correct methods.

Jim Rogers

PS. good luck with your repairs.

Delawhere Jack · September 16, 2012, 09:40:58 AM

This should help. P220, but it's the same design.

http://www.youtube.com/watch?v=slMP05G8LnQ

Chuck White · September 16, 2012, 01:03:36 PM

Jack; Thanks for posting the video.

pineywoods · September 16, 2012, 02:07:55 PM

What the adjustment does is alter the length of the lifter, which sits between the lobe of the camshaft and the end of the valve stem. When you run out of adjustment, pull the valve out and grind off the end of the valve stem. On some older engines, grinding the stem was the only adjustment..

Delawhere Jack · September 16, 2012, 03:38:33 PM

Does anyone know what the service limit for compression is on a P224? I've searched, but didn't find anything conclusive. I just tested mine and got readings of 123 and 125 psi. These readings seem pretty high.

Joanie · September 17, 2012, 09:55:36 PM

Thank Y'all so much for the info.

Okrafarmer · September 17, 2012, 09:56:58 PM

Looks like we're doing ours soon, so we may have more questions. We'll see. . . :

sawguy21 · September 17, 2012, 11:16:32 PM

Jack, the engine should have a compression release built into the cam that momentarily bumps one of the valves off it's seat on the compression stroke while cranking, if the valve clearance is too wide this feature is defeated making the engine hard to start. When setting the valves roll the flywheel one quarter turn past TDC on the power stroke.

Jim_Rogers · September 18, 2012, 08:04:20 AM

I may try and adjust my engine's valves myself this time.

My first question is without tearing the cover off the flywheel and fan area, how do I tell when the engine is at Top Dead Center (TDC)?

Jim Rogers