Re: 1995 merc 115 oil injection
Also, plastic gears are used and last of many things. Many automotive manufacturers use plastic gears in the transmission to drive the speedometer.
And yes you could disconnect and premix, but if the pump failing bothers you then that would apply to everything on the engine. A connecting rod, piston, bearing, etc. any of these could fail and cause engine damage. The old AutoBlend wasn't the best but the newer oil injection system works well and like ibnfshn said, you seem to never hear about those thousands and thousands that are working fine.