Thread: testing for burnt valves

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ok, used a leak down tester last night and every cylinder came out around 20%, +/- 5 or so. On each one I could detect a sound if I put my ear to the exhaust pipe, it was faint as hell so I don't know if it was something else I was hearing.

Originally Posted by tcodi

ok, used a leak down tester last night and every cylinder came out around 20%, +/- 5 or so. On each one I could detect a sound if I put my ear to the exhaust pipe, it was faint as hell so I don't know if it was something else I was hearing.

sounds normal to me. did you use a vac. gauge?

no, I haven't run it yet with a vacuum gauge cause I don't have one, but I'm going to get one. Some things are still a little sketchy, like if I'm on the throttle real hard and then have to shift I sometimes get a pop out the exhaust. After taking all the plugs out last night I see that they are looking lean, which I don't understand because when I was warming it up before doing the test it was burning my eyes.

you can have a rich idle and a lean WOT. 2 dif. parts of the carb. what kind of carb. do you have?

"but wouldn't that only tell me if the burnt valve is on the intake?"
this is a ? you had before and no one answered it. this would tell you the burnt valve was on the exhaust, not the intake. if the intake valve was leaking then you would hear comp. blowing back up through the carb.