I just did a compression test on my ZC using a tester from harbor freight which I've heard arent the best, when I was tightening the connector once it had small resistance the hose would rotate inside the connector. I ended up with 146-149-151-152, consistant but somewhat low. Could this be the tester? It just didnt seem to be snug inside the spark plug hole. What kinds of testers do you all use? Any opinions are appreciated.

 

I just did a compression test on my zc too. I didn't do it the right way though (warm engine and throttle plate wide open). My results were 150,140,155,150.......i just rebuilt then engine with low compression 9:1 pistons. im not sure how much that would change the compression but i would imagine yours should be higher. good luck!! oh and by the way that 140 is where i gapped the rings just a bit too much.

 

Well I know the throttle plate wide open is how its done, and I did mine on a warm engine also because I dont like the idea of doing 20+cold cranks. I didnt let it get to operating temp, just let it run for a min or so to let the oil circulate. Oh well, I'm satisfied with them all being consistant.

 

Those #'s are pretty low... they should be around 180 or so... I think 130 is the service limit... try pouring some oil down the plug holes, and make sure the engine is at operating temperature (meaning go drive it around). If the compression jumps when you pour the oil in, you have shot rings.

 

I honestly wouldnt worry about those compresson numbers at all..

those harbor frieght Comp testers blow ***..

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by AbaZ &raquo;</TD></TR><TR><TD CLASS="quote">I honestly wouldnt worry about those compresson numbers at all..

those harbor frieght Comp testers blow ***..</TD></TR></TABLE>

Yeah thats pretty much what I've heard, sometime this week I'll be borrowing a different one from a friend so I'll try again and see whats up. Theyre consistant so I'm not worried. Maybe I just have very little carbon buildup. Another guy on here got similar numbers and put down 113 to the wheels on his stock ZC so...

 

I checked mine about 2 weeks ago & got 170 across the board.