What is the mix/ration for my small john boat engine?

I've got a small Johnson 4 engine and last time i tested it out I mixed at 50:1 with penzioil marine oil for 2-stoke.. now thinking, I'm not 100% sure it's even a 2-stroke so what are the odds? and also I'm new to boating and the engine bearly runs and I have to tinker with it to even to get it to do so.. so what should be checked out again before trying it out and also what kind of oil does the lower unit use? and any other info is greatly appreciated