Doug,
No confusion, I just hear a lot of things like, "the oil pump is just one more thing to fail". Here are some of my thoughts. It is true that other components can fail. Like if the small oil lines get damaged oil can get pumped out of the lines instead of into the injection ports. Which could also occur with fuel lines but we don't remove the fuel pump. The filter in the oil tank line could get clogged preventing oil from getting to the pump, but so could the fuel filter. So we change the fuel filter on a regular basis. My point is a properly installed and maintained oil injection system is just as reliable as any other system on the engine. Interstingly Rotax recommends changing the spark plugs every 25 hours. Replacing the jet needle and needle jet at 150 hours. Overhauling the engine at 300 hours. But nowhere in the maintenance manuals is there anything about replacing any component of the oil injection system. With the very high liability concerns Rotax has you would think if they thought there was any probability of failures they would be recommending replacements or changes or something. I see pre-mix as a personal preference and that is ok. Just remember to periodically drain your fuel tank and put fresh pre-mix in so that you know you have 50:1 and not something like 40:1 due to fuel evaporation. Excessive oil in the fuel will cause faster carbon build up and other problems.
