Misfire at cruise, popping/afterfire at 3000RPM

Check and be certain the valves were not open on no4
How do I do this? At first that’s what I suspected, so I backed up the crank and then moved it forward to see the best numbers I could get. I also tapped the rockers with a rubber mallet, in hopes either valve would seat.


These numbers do not support each other; one of these tests is no good.
And I'll go out on a limb and say the leakdown is wrong.......... because the numbers are way too big....... I'll guess by a factor of 10.... at least.
I thought the same thing. Add in the factor of someone who’s only done one other leakdown test in his life, and you end up with lots of room for error.

Maybe I’ll try another leakdown tomorrow.