62 Merc700 Compression specs

[Antonino]

I'm resurrecting a 1962 six cyl. Merc700 which has been in storage for years. I wet the cylinders with WD40 which promptly came out of a small hole above the gear case near the leading edge. Compression across all six cylinders was consistent between 85- 90psi which I think is too low. I wondering if the lower crank shaft seal is no longer sealing given the engines age and low uniform compression readings and the flow of WD40 from the upper cylinders to the gearcase drain. Any suggestions will be much appreciated.

 

[racerone]

Sorry----But the lower crankshaft seal has nothing to do with compression in the cylinders.-----You are aware that this motor has 6 separate / sealed crankcases.

 

[Dave1027]

90 psi might be normal for a 1962 motor. Supposedly, my old 1963 Johnson can only hit 90 psi if the cylinders are perfect.

 

[racerone]

Compression values can be confusing !

 

[jimmbo]

Some of the WD40 went out the Exhaust Ports and that is how it ended up in an exhaust housing drain, located on the Gearcase.