I builting a dumas 36" hydoplane and it calls for a .21 engine. Can I use your 0.18 marine engine? RPM specs are about the same and so is the horese power.
If I go wit your 0.21 (3.5cc) marine engine, can I convert the exhaust used on your outboard (model #8935) This muffer system looks like the one I have on a older 3.5cc I used in a similar Dumas Hydoplane