Just rebuilt a motor and the compression is 10:1. 1st cylinder is 170, 2nd cylinder is 200 and 3rd is 200 we did not check the 4th, because the mechanic said they all have compression so timing is good. I think that is a huge variance. Is it me or is the timing good. I rebuilt a kia motor (wifes car) and when I did a compression test they were all even.

 

Yeah, thats more then the difference limit allowed.

 

Time to redo this test........ If the guy didn't even check #4 then how do you know if he had the throttle plate opened on the cyl #1 check?? How many miles are on the engine? Verifying cam timing is pretty easy.

 

+1

A proper retest should be done.

 

Just Fixed the timing it was off a tooth. New reading is 1st-150,2nd-175,3er-175 & 4th-175. We will see later what the compression is after everything seals.

 

Just pulled the head the variance is just too high...sure enough there is a ding on the #1 piston. The dude who put on my timing belt screwed up

 

What does throttle plate have anything to do with compression? I think I wrote the motor is fresh

 

Throttle plate open will increase the compression result (gets more air in given cranking time). If he had it shut when testing cyl 1 it could explain the the low result, however you have since said the timing was off and the piston was dented/contacted valve and this explains it. Check your valve is not bent also.

 

Good to know