yes it is an inboardAn inboard 2 cycle? That would be odd for sure.
Plenty of 2 cycle outboards still around.
Warren - thanks a lot. the link you sent is exactly the right one. now I have a starting point.I think some of the older C&C 25's came with an inboard Vire engine that may be 2-cycle.
See: http://gofree.indigo.ie/~vire7/