• Don't miss out on all the fun! Register on our forums to post and have added features! Membership levels include a FREE membership tier.

Engine Compression Test Question

C

cokingcat

Active member
Jan 28, 2008
148
28
28
I have two 900 EFI sleds. While the sleds were cold I pulled one spark plug and tested the cylinder. And I did the same for the other cylinder (then the same for the other sled). Then I let them warm up for a few min. Ran the same test but the numbers stayed the same. I thought that the pressure should have increased, am I wrong? Also what should my numbers be at 9,000 warm or cold? Thanks Ross
 
7

76FOMOCO

Well-known member
Apr 18, 2007
4,446
1,235
113
Nampa, Idaho
when i test them i do it with the motor warm, every thing expands to some point closer to the real running temp. at your alt and depending on gauge some place about 115-125 psi. the thing your looking for most is for them to be within about 5 psi of each other.
 
Premium Features