allis g engine compression

hello I am helping a friend with a g as it runs good and starts easey but smokes so we thought that we would take a engine commpression test to see if ihe rings or the valve guides are worn but cant start to investagate because we dont know what the compression specks are and wonder if any of you might know thank you

BOB
 
90 to 95 lbs at starter motor speed.
Get the engine hot and shut off the gas and let the engine run out of gas. Remove all spark plugs. Remove the air filter and have the throttle and choke wide open when you do the test.
Leave the ignition off when doing the test.
 
I once tested a smoker G and it tested an even 90 psi in all cylinders. So engines can smoke and still have good compression. I suppose it had valve guide problems.
 
You do have compression rings and an oil ring. It is hard for oil to run up hill to burn and smoke.

GAllisRebuildofEngine2-vi.jpg
 
Wish you'd tilted that camera uphill a bit more, then snapped and posted some pictures of that nice looking G in the background.
 
Could be but I would doubt it. In that engine if the guides were that bad it would be hard for the valves to hold an even 90 pound pressure.

I would sooner think that it had over heated and the oil ring got seized to the piston to let oil get by.

engines like these without water pumps used in factory mules would often over heat from not paying attention to water levels and start smoking. They would replace the rings without any other repair and put the mules back in operation.

Really hard to tell if that would be the problem without being the operator from the start though.
 
Dick, thanks a bunch for giving access to those photos. From your upload dates, I take it is a recently completed project. It looks very nice. Just doing the restoration is task enough, but adding the photo documentation too is quite an accomplishment and is much appreciated.
 
Over 9 years ago if you call that recent. :)^D

I finished it in November of 2002. I used it to cultivate pumpkins the summer of 2003. I put other pictures in the album at later dates. The second picture was taken after I had repainted it before taking it to a show. My tractors are stored in the big blue barn under the stars.
 

Yep, they should scrape the excess oil off and away from the compression rings, or it will smoke bad..

Ron..
 

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