hey gents
I've got a 16 foot starcraft aluminum with a 1979 70hp mercury. The prop thats on it now is a michigan prop 12 1/2 x 8 and it came off a pontoon. I swapped it over and I feel like the speed isn't there. I am hitting 5800rpm on my new tach but going from. 5krpm to say 5800 its like no additional power at all. Also here a pitch change in tbe motor while running wot. Kind of a slight up and down hum. Don't know much about props but maybe its a torque or thrust prop? I run about 27mph but I feel I should be getting closer to 33-35. Tbe boat weighs 800lbs I'm guessing no more then 1000. Its about a 70 inch width. My old Chrysler 55hp pushed my 17 foot flat bottom at 30 so I'm scratching my head. Just looking to get a little more speed out of it. It has a hydrofoil on it and that solved my cavitation issues.
Thanks guys
Tony mac
I've got a 16 foot starcraft aluminum with a 1979 70hp mercury. The prop thats on it now is a michigan prop 12 1/2 x 8 and it came off a pontoon. I swapped it over and I feel like the speed isn't there. I am hitting 5800rpm on my new tach but going from. 5krpm to say 5800 its like no additional power at all. Also here a pitch change in tbe motor while running wot. Kind of a slight up and down hum. Don't know much about props but maybe its a torque or thrust prop? I run about 27mph but I feel I should be getting closer to 33-35. Tbe boat weighs 800lbs I'm guessing no more then 1000. Its about a 70 inch width. My old Chrysler 55hp pushed my 17 foot flat bottom at 30 so I'm scratching my head. Just looking to get a little more speed out of it. It has a hydrofoil on it and that solved my cavitation issues.
Thanks guys
Tony mac
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