Compression Testing 300

[HobbyFarmerInWI]

Does anyone have the factory spec of what a 148 gas engine should be.

Does anyone have any idea what, after 50 yrs of use, would be an acceptable compression readings?

 

[Joe (Wa)]

Service manual: Gas engine is 140 - 150 psi, not to vary more than 5 psi between cylinders.

Well that is fine if need a hard working, full power tractor. For a light duty, hobby tractor as long as you don't have significant blowbye, I would guess this engine would start and run decent down to 110 or 120 PSI. Don't expect a lot of lugging power. The spread is important, 10 psi gets my heartburn going.

Use a quality compression checker and a known good battery. I usually have a charger on the battery during the check to ensure the same cranking rpm for all cylinders.

Joe

 

[HobbyFarmerInWI]

Thank you Joe, that was exactly the info I was looking for.

 

[wayne2]

Joe, you are always on the Mark!!! I gave up on comp. testers in 65 they never said anything good!!! My 300 148 always starts in spring(knock wood)does some log yarding,rakes the wash boaded Co.road-makes my wife smile when she drives it. couldn't ask more for adding gas and a little oil here and there. W