Mercury 1150ESS.Model 1971.

[Ragnar]

The Service Manual for this inline 6 cyl.engine does not say anything about the comp.ratio.It is probably fairely low --- Anyone knowing this exactly ?? <br /> Second question: What is considered a normal compression pressure (through the plug hole) and also if possible the crank case pressure and suction (inHG)for anyone cyl.?

 

[ODDD1]

Re: Mercury 1150ESS.Model 1971.

Ragnar i seem to remember seeing 6.8 to 1 on the merc inline motors.minimum comp pressure to run decently is 125 psi.........I have never checked crankcase press/vac...if the idle/low speed operation is weak with good cylinder comp,is because of poor air management in crankcase.......