Re: adding oil to gas vs. auto injection
How often does an oil pump on an automobile fail? Do we worry about that destroying our engine?
I think that auto mix systems failing are an urban legend. Don't listen to the low oil warning or run without oil and you will ruin the engine, but that's not the pump's fault.
This isn't even a good comparison. In our 4-stroke cars we have absolutely no choice because the lubrication system is not even connected to the fuel system. The oil and the fuel never mix. On a 2 stroke, the oil and gas mix, it is just a matter of whether a person or a piece of machinery is doing the mixing.
Do 2-stroke oil injection systems fail. You bet they do, but they are for the most part very reliable. I ride snowmobiles and although I have never had an oil system failure I have a friend that had one fail and lost the engine.
As was stated before it depends on the system. My father had a 60 hp Johnson with the VRO system. Not known for its stellar reliability. We disconnected it and ran premix in that engine. I now have a 115 Mariner and relatives have had many Mercury's and they have a reliable proven oil injection system. So, the system on my Mariner is still pumping oil into the engine.
Can someone forget to premix?? Yes, I suppose, but I've premixed for 20+ years before the boat I have now and I never forgot because it was a given that you add oil every time you fill the gas tank.
Can someone forget to add oil to the oil injection tank?? Yes. I have done this because the big oil tank lasts for many tanks of fuel. Has it ever gotten low enough to be a problem?? No, but if someone were to get complacent enough with checking the level then it could be a problem. I will tell you that when I got my boat the warning buzzer did not work. The buzzer itself was bad and all the sensors in the world don't mean nothing unless the sensor has a way to notify you.
Like I said, to me it depends on the system whether I would unhook it. Some I would unhook, some I wouldn't.