Compreshion Check

Mon Jun 09, 2014 12:59 pm

Scuzzy here, Been away for Years on a Cub-Had a LowBoy 25 Years ago n going to look at one in an hour or so, Need to know What Kinda Compreshion My Gage should show on a Fair Engine? My old LowBoy was a Great Tractor but Devorce n a Jap Crap has kept me away! Just don't want to Jump too Quickly! Anything elce I should Check? Thanks in advance! Scuzz :thanx:

Re: Compreshion Check

Mon Jun 09, 2014 2:07 pm

Should be in the 110-125psi range if its a good health engine. If your below 90-100psi you may notice power loss and hard starting. One other to bear in mind is that you want the readings to be with in 10% of each other. thus if you have one cylinder with 80psi and another with 120psi that would also be a negative.

I would do both a dry and wet test to confirm.


Re: Compreshion Check

Tue Jun 10, 2014 12:32 am

Thanks for the Info, I knew they were to be Consistant but had no Idia about the Readings! Know its a 7.5 to 1 Compreshion Ratio But had no Idia what to look for on a Gage-was Figuring 80 to 100! Thanks agin! Scuzz

Re: Compreshion Check

Tue Jun 10, 2014 12:43 pm

110-125 would be what to expect on a newly rebuilt engine, one that has a lot of hours will be lower.