[McGillicuddy]

Can you post a picture of this boat? I don't think a 21 was made in '75.

The production year of a 21 would make a BIG difference in motor re-power recommendations as the pre and post 70's SeaCrafts 21s were very different boats.

Based on previous power I would guess it was if indeed a '75, its a 20' model. If a 20, I think the Etec 115 or 130 would be a great match, or even the Optimaxes in that hp range. I think the Suzuki 140 gives the best power to weight 4 stroke solution.

If he doesn't need to exceed 35mph, he might even consider an Etec 90 which is lighter an old 130 Yammie.

If its a later 21' the 150 h.p. might be the way as I think the 21 had an 8 ft beam and could float the extra weight better.

I think the fellow who suggested Etec was right on. Direct inject 2 strokes are a new breed of engine. Quiet, clean, gas misers, typically lighter than 4s and powerful!