1971 Fastwin 18hp - Missing cylinder

[pl2442]

At WOT the motor seems to run good on both cylinders, but when i drop down to trolling speed it drops a cylinder. I also noticed afterwards there was black oil leaking out of a weep hole in the lower unit. Im assuming i am running really rich. Would running rich cause the cylinder drop or what else could it be?

 

[Boobie]

You could be dropping spark at slow speeds. Check your ignition system.

 

[kimcrwbr1]

Always start at the beginning what are the compression numbers?