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Re: Two rear cylinders not Working?
Posted: Tue Nov 29, 2011 2:51 pm
by cruzoropeza
87-90psi If I remember correctly and I removed the carb and there was fuel in the bowls, the last thing I need to check on the week end is manifold for leaks
Re: Two rear cylinders not Working?
Posted: Tue Nov 29, 2011 6:04 pm
by westernair
87 to 90? Did the pressure stay the same or how much did it drop over 60 seconds?
I would also do the test just as is and also with a squirt of oil into the cylinders.
What was the compression of the other two cyclinders. I may be wrong but I would think they should all be over 140
Re: Two rear cylinders not Working?
Posted: Tue Nov 29, 2011 6:55 pm
by cruzoropeza
I also thought it should of been over 120psi but I compared it two the two "good" cylinders, the ones that are working I'm getting 82-87psi and the "bad" ones I got 89-94 it held is for over 60seconds. I'll try the "squirting oil" and test it again thanks guys!!!
Re: Two rear cylinders not Working?
Posted: Tue Nov 29, 2011 7:23 pm
by Jim LaGuardia
If you don't have at least 120PSI after 5 revolutions in each cyl, you must check the valve lash before continuing(.2mm) then compression test again. If compression is still low be prepared to spend some money for a top end.
Re: Two rear cylinders not Working?
Posted: Wed Nov 30, 2011 6:59 am
by Stekay
Jim,
I'm assuming the 120 PSI is with a warm engine and wide open throttle, correct?
Re: Two rear cylinders not Working?
Posted: Wed Nov 30, 2011 1:12 pm
by Jim LaGuardia
Temp is not important, throttle plates always stay closed when doing a compression test, just crank engine for 5 revolutions and read results.
With the numbers posted, I would suspect the cam lost a bore plug and the pistons may have been damaged from the loss of lube.
Re: Two rear cylinders not Working?
Posted: Sun Dec 04, 2011 7:04 pm
by cruzoropeza
I'm a very happy man!!!!!!! It turns out it was the manifold gasket, cut my self a couple of new ones and she running better than ever. Thank you all for your helpful tips! AMAZING!
Re: Two rear cylinders not Working?
Posted: Sun Dec 04, 2011 10:22 pm
by Pinzgauer Pete
Bows...you're welcome!

Re: Two rear cylinders not Working?
Posted: Mon Dec 05, 2011 9:02 pm
by cruzoropeza