I bought my boat, Triton 191LTS, and motor in 2007. The motor has maybe 55-60 hours on it. Yep, I dont use it often enough. Optimax 150 saltwater. The oil in the tanks is pretty old! I did add a bit some few years ago. Have used the boat several times in the last 4 weeks. First time when I cranked it, there was a bit of light white smoke??? coming out, just a tiny bit at idle. Motor ran great and after going across the lake it was not smoking anymore that day. Third and fourth times I used it the same thing, a very small bit of what appeared to be almost white smoke coming out at idle. After up the rpms it cleared out totally.

So, the question; is the oil too old and should it be replaced - should I toss that old oil and put new oil in? It has two small tanks with about a half gallon in each and they are 3/4's full. I read that the shelf life of oil is about 5 years sealed! So I would have to assume that if I dont use the engine enough to keep refilling it with new oil, it could be fouling or bad?

Or, is there another issue? I dont think it was fog the cold water and warm engine or similar.

TIA

You're fine it's not like gas it takes years for oil to go bad. Everything you mentioned sounds normal.