DaveInGA
Well-known member
Got a battery and was able to complete a compression check on my 1986 Mercury 75 HP two cycle motor. I think I got lucky with this boat. Compression measurements are as follows:
Cylinder 1. 155 psi
Cylinder 2. 150 psi
Cylinder 3. 150 psi
Cylinder 4. 150 psi
That's a variance of between 3 and 4 percent tops. I had some variance I think due to how tight I screwed the compression tester into the cylinders. I suspect that may account for the 5 psi difference on Cylinder 1. In any case, it's well within the 10% and the over all compression levels seems to be real good. I'm happy.
I'm thinking I can remove the cables/controls and remove the motor from the boat so I can repair the transom.
Cylinder 1. 155 psi
Cylinder 2. 150 psi
Cylinder 3. 150 psi
Cylinder 4. 150 psi
That's a variance of between 3 and 4 percent tops. I had some variance I think due to how tight I screwed the compression tester into the cylinders. I suspect that may account for the 5 psi difference on Cylinder 1. In any case, it's well within the 10% and the over all compression levels seems to be real good. I'm happy.
I'm thinking I can remove the cables/controls and remove the motor from the boat so I can repair the transom.
