Todays 2 strokes like mercury optimax and evinrude etec are usually direct injected,computer controlled wonders.In the case of evinrude you also have pinpoint oiling which is not the same as the conventional sense of oil mixing.Evinure has several videos the explain their system way better than I ever could.I don't believe Yamaha 2 strokes ever got as high tech as opti or etec.