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Compression test 125psi good or bad
Posted: Sun Jan 27, 2008 9:54 am
by jamesok
I bought a gunson compression tester from halfords.
Did cylinder 2,5 and it read 125psi
Is that bad or average,there is some bore wear
James
Posted: Wed Mar 26, 2008 11:01 pm
by mk2escortjimmy
is it a screw in or push in type? if its a push in, they can be difficult to seal and give low readings, 125 is quite low i think, my rebuilt x-flow got about 180 after a few thousand miles. Does it smoke? Unless u have no money, get it rebored with oversize pistons just to be sure
Posted: Thu Mar 27, 2008 7:38 pm
by r2d2hp
Does it have a problem or did you just want to test the compression.
When you did the test did you hold the throttle open, if not try again and see what readings you get.
Posted: Fri Feb 06, 2009 9:53 pm
by jef
hi mate.
you should test them all, it's just as important - if not more important - that they're not too far out of the way of each other..
from my experience (bikes usually) 125psi will be okay, but I'd want more like 160 I think, what are your gaskets like + if you can take the cylinder head off one bank & turn it over while you check the top of the cylinder sleeves (where the piston rings slide upto), and check there aint a lot of wear there. if there's no wear you just need new piston rings/gasket, if there's a lot of wear, you will want a hone/rebore in the near future..
you don't want the least compression to be much more than 10psi below the most compression cylinder.. 2 or 3psi if you plan on race tuning it.
cheers mate
James
ps mate
can u say what engine u got so maybe someone know the factory compression ratings
