1996 Mercury 25 compression spec?

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Bowhunter1661

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Just curious if anyone knows the spec for these motors. This motor has the chrome cylinder bores as well, not standard steel. I am looking to buy the motor from a guy in Missouri but when he tested it on came back at 91 on bottom and 97 on top (This was cold and not oiled). I have tested a few motors in the past and almost all were in the 120 range. I have no experience with chrome lined bores not sure if they need to be hot or oiled..
 
I'm not surprised by those low readings. The test was done incorrectly.

According to the 1996 merc manual for 25 hp 2 cycle max compression is 180 psi. Minimum is 127 psi. Below 120 indicates problems. No more than 15% difference between cylinders.

This manual is on boatinfo.no

Procedure:

Run engine until thermostat opens.

Remove all plugs. Hit kill switch.

Install gauge.

Open throttle plate to WOT and crank. Stop when highest reading is achieved.

Rinse and repeat.
 
Excellent, that is exactly what I needed. Does anyone know anything about there motors? Are they decent? Last awhile? Not too sure about the coated aluminum cylinders on these motors..
 
My boat has a '95 and I don't think it has the nickel cyl bores but regardless it's been a fantastic motor. Flawless so far, many, many hours of trolling.
 

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