Mercury 115 Oil System

[Jerry Young]

I have a Oil Injected 1995 Mercury 115hp, 2 stroke, 4 cyl engine. I am suspect of the oil system. I have started augmenting the oil system with 100:1 oil in the fuel tank. After running for 5 hours, there is oil used up from the oil storage tank, but when I check the plugs, only the top 2 have oil on them. Cyl 3 and 4 are much cleaner than 1 and 2. Does the oil system in normal operation add the oil in front of the carb or after the carb? Can I eliminate the oil injection system all together by using a 50:1 oil in the tank? Can the carbs handle the oil in the tank method of lubrication?

 

[racerone]

That motor only runs on the top 2 cylinders at idle.----Oil is mixed with the gas before the carburetors.

 

[Jerry Young]

Thanks. That explains a lot. So, with the oil being mixed before the carb, it should be safe for the engine and the carb to run a 50:1 mix in the tank and eliminate the oil injection system, yes?