1979 115 hp Evinrude leak down test

" I have a 1979 Evinrude 115 h

" I have a 1979 Evinrude 115 hp engine with one dead cylinder at low rpm. I think it is working ok at higher speeds. The compression is 120 in all cylinders but when I pull the plug wire off the number four cylinder it does not change how the engine runs. To make sure the ignition system was ok I interchanged coils and then power packs but number four cylinder seemed to remain dead. How do I do a leak down test. I have a compressor and some gauges. Or, perhaps I have missed something else someone can help me with. "

Have your motor tested on a d

Have your motor tested on a dyno to check full power operation.You can also remove the air box cover and look at the amount of fuel coming up the high speed jets ( use a flashlight ). If you continue running a motor with a fuel problem you risk major engine damage from a lack of oil .Use an inductive pickup timing light at full power to verify spark at all RPM ranges.

"Sherman.... In addition to Sp

"Sherman.... In addition to Sparky's comments, I would add the following.

Have the carburetor face plate off and the engine running at idle. Stick two fingers into the carburetor throat of the cylinder that isn't responding (acting as sort of a choke for that one cylinder). If the rpms increase, that carburetor has a problem.

Joe "

Thanks I checked the spark wi

Thanks I checked the spark with the timing light and it is ok. I choked that cylinder with my fingers but no change. I sprayed some gas into that throat and I think I got a little response but it flooded and died. I guess maybe I could pull the head or exhaust cover and look at the bore and rings. This engine has been rebuilt about 200 hours ago and I rebuilt the carbs just a couple of weeks ago to see if that was the problem but the problem didn't change.
May be it's time for a new motor. 2 or 4 stroke?
I have been out of work for over a year so I have plenty of time to work on this project but little money.