Stock Compression for a 1983 12A motor.
02-21-17, 05:39 AM
#3
Not disputing what your book says, but would that be the minimum acceptable? Seems low, normally, good strong compression is 120-125psi. I normally see 10 to 15 more cranking rpms too. Depending on the condition of your starter and battery cranking rpm can vary, and the slower you spin it, the lower the psi will read.
02-21-17, 09:48 AM
#4
Waffles - hmmm good
iTrader: (1)
If you use the mazda or similar rotary compression tool, you will see the numbers mentioned
above.
If you use a regular tester and are watching the bounces its very hard to tell what the actual
compression is. It only tells you if all the faces have the same compression or not really. In
you other thread I think you saw 75 on the front and 65 on the rears which is probably not
bad using a regular tester holding the button in.
above.
If you use a regular tester and are watching the bounces its very hard to tell what the actual
compression is. It only tells you if all the faces have the same compression or not really. In
you other thread I think you saw 75 on the front and 65 on the rears which is probably not
bad using a regular tester holding the button in.
02-21-17, 10:09 AM
#5
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If you use the mazda or similar rotary compression tool, you will see the numbers mentioned
above.
If you use a regular tester and are watching the bounces its very hard to tell what the actual
compression is. It only tells you if all the faces have the same compression or not really. In
you other thread I think you saw 75 on the front and 65 on the rears which is probably not
bad using a regular tester holding the button in.
above.
If you use a regular tester and are watching the bounces its very hard to tell what the actual
compression is. It only tells you if all the faces have the same compression or not really. In
you other thread I think you saw 75 on the front and 65 on the rears which is probably not
bad using a regular tester holding the button in.
02-21-17, 06:26 PM
#7
You can use a piston compression tester, but it takes some experience knowing what to expect or how to correlate the reading. Without knowing the cranking RPM (one of the things a rotary compression tester gives you) it can be kind of a ballpark check.
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