Compression Test

[SoguRacing]

how to do a compression test:

1 remove plugs
2 install gauge
3 disconnect ignition/fuel..one or the other..or both
4 prop open throttle body 100 percent
5 crank engine over 6 times while "noting" the first puff which should be at least 50 percent of the total psi...and the final puff on the gauge. Ex. 75psi would be 50 percent of 150psi of the final puff.
6 repeat for each cylinder and all final puffs should be within 10 percent of eachother. If not then you have a problem. On a rebuild engine your compression will be low at first until the rings seat. I wouldnt worry though i did my compression with 100 miles on a rebuild and my numbers were 155,160,155,155 with all other numbers within spec. s13 SR