As far as 4-strokes go, don't believe any of the hype about their maintainance. I have mostly 4-strokes, and they ae no more difficult to run or maintain that a 2-stroke. And you DON'T need a tach to get them to run right.
Except for adjusting valves, bent push rods, burnt valves, etc. Granted those things don't happen often, (except for adjusting the valves), but you never have to do them on two strokes.