compression tester

[danbobsR]

I havent used a compression tester before do you just kick it over 5-10 times or so? kick it like Im starting it or just kick it. will a auto parts store compression tester do the job or do I need a specific kind. I got me a 330 with a fresh top end only showing 150lbs with a auto parts store tester sounds low to me Im making sure Im doing the test right.

[86-250Rnut]

Yup, just kick it over a few times. i think the quad should be warm when you do this so its lubed up good and other reasons im not to sure about.
i just bought a 50 dollar one from Bumper to bumper, it was the only one they had. i wouldnt get hte cheapest one you can buy form the store, but i wouldnt want to get the best one either unless you do alot of testing and need to be very accurate. so just get the one in the middle:cool:
Mitch:macho

[GPracer2500]

Keep the throttle wide open and just keep kicking until the guage stops climbing. Shouldn't take more than 5-10 strokes.

The reasoning behind doing the test with an up-to-temp engine is so the rings will seal as much as possible. All the engine components should idealy be at their fully heat-expanded dimensions.

[86250rrider]

the threaded ones are obviously the way to go. i test always test cold. wot with repetitive kicks until needle wont go any higher. put number in repair manual for future reference. when it drops 15-20 percent ...tear it down. hope this helps a little :macho

[danbobsR]

what kinda comp should a 330 have? I dont know what kinda dome is in it.

[86250rrider]

my .030 over was at 185 before the port work, now its at 175 with the top slice of the three piece gasket with some head milling (don't remember how much). 185-190 psi is very healthy and borderline pump gas friendly. stock is around 160-170 i think. i need to send my extra head out to be milled for more squeeze on mine. 150 sounds low to me unless you have all top end port work. let me know.......K

[danbobsR]

the guy told me it had trx9 but the cylinder had trx7 on the bottom I really dont know what I got bad thing about buying a motor used.:confused: