so, i now have a rather splendid Yamaha 90hp two stroke engine on my dory. (thanks Dan!
(keep me in mind when you ready to change again LOL!)
anyway, the issue i am trying to tweak is the speed when fully laiden.
the boat is heavy, 17.5ft Dory about 800kgs.
and when its just me and three passengers she slips up onto the plane no problem, and tootles along at 30 mph, great!
but when i swap the 'cargo' for 4 burly divers and all their gear - probably and increase of 200kgs more, i drop to about 12mph and she wont quite get on the plane. bad news, huge fuel difference, and speed of delivery to site etc.
anyway, the prop currently is 13.5 x 15. gear ratio 2.00 : 1, revs 5500 max.
so should i change the prop? if so, what would you recommend?
or would hydrofoils do the trick? and again if so, which ones?
i dont think i am far away from cracking the issue, but would be very grateful for any tips
thanks in advance