I had a 90 and 115 HP 2002 engines. I eliminated the oil pump gear on the 90 because I felt like doing it, obviously running pre-max gas afterwards. I didn't feel like it on the 115.
One thing I noticed and may have been the reasoning for the initial change is that I'm 84 and don't go boating much, maybe once per annual quarter for an hour or so on the water. Doing the things that I have been doing for decades, what you are supposed to do to get an engine started, but having to deal with the EPA mandated squeeze bulbs, fuel was taking awhile to get into the combustion chamber. Since the oil was injected by a pump geared to the crankshaft, as the engine turned over with the starter, it was pumping oil but not gas.
The result was a "smoke fog" when the engine started, clearing out the excess oil. Pre-mix solved that problem. I didn't do the 115 because I was too lazy by then and too lazy to take the boat out much. Was it a good idea to do the 90? Absolutely. If you boat frequently, it probably would be a waste of time and less convenient filling up if you just had to add gas to the fuel tank.
