Speed on 23 seacraft

[peterb]

I have the same setup (twin 200 Yamaha's)on a full flotation bracket. I can get them up to about 57 MPH. I am running 21 x 14 3/4 prop's. I also, have 19 x 15 1/4 props. I will give them another try as I just had the engiens lowered one notch (last summer I raised them two notches, one notch too high).

At cruise (30 MPH to 40 MPH) I get around 1.7 miles per gallon. These are 0X66 engines. If I had HPDI's I suspect that I would get around 2 miles per gallon.