James Gasek

Definitely don't think I would have stretched it, I was only at around 4500 rpm.

sixshooter

iTrader: (12)

That's good

codrus

I have always been told that absolute compression numbers will vary a lot with technique, battery voltage, starter health, the specifics of the compression tester that you use, etc, and that relative compression numbers are a more reliable indicator of bad health.

--Ian

hks_kansei

As others have said, short of spending heaps on a calibrated comp tester, they're best used as a comparison tool.

Out of curiousity, did you do the test with the throttle open? leaving it closed can cause lower numbers.




IF the tester is correct, 140 is low, for an NB the Mazda minimum spec is 160 give or take. (ideal is 220 or something, dont have the OEM workshop manual handy atm to check)

James Gasek

Throttle was wide open, but I only cranked it like 3 times like I said because I thought that was the way it was supposed to be done or whatever. On cylinder 1 the first time I did it I actually cranked it over like 6 times and got around 150 but I thought that was too high and I thought maybe turning it over too much would give me too high of a reading or something even though now that I look back at it there's no way that would be possible haha. But yeah not too concerned

curly

iTrader: (25)

I bent three, actually. Pull your head.