Classic 15-footer with F70
Posted: Sat May 05, 2018 11:54 pm
Recently I was able to upgrade the engine on my [1987] 15-footer to a new Yamaha F70. The dealer gave me a 13-1/2 x 14 pitch propeller to try out, and, as I suspected. [the engine] was very under-propped. [The engine accelerated to] 4500-RPM [and the boat speed was] 21-nautical-miles-per-hour]. [The engine accelerated to] 6400-RPM [and the boat speed increased to ] 31-nautical-miles-per-hour
I went back to the dealer, and he then gave me a 13-5/8 x15 pitch propeller to try out. I will have the outcome tomorrow.
I suspect that [the engine] will also be under-propped [with this new propeller].
From what I've been reading on forums it sounds like a 17- to 19-pitch is the sweet spot.
My 15-footer is a very light hull. [It has] a side console and a 15-gallon fuel tank. The engine is mounted three-holes-up on the transom.
I live in Alaska and often times we use our boats to haul ATVs to outlying island to ride, so I do haul a bit of weight at times. But ultimately [highest] speed is my goal.
Any input or general performance talk would be appreciated.
I went back to the dealer, and he then gave me a 13-5/8 x15 pitch propeller to try out. I will have the outcome tomorrow.
I suspect that [the engine] will also be under-propped [with this new propeller].
From what I've been reading on forums it sounds like a 17- to 19-pitch is the sweet spot.
My 15-footer is a very light hull. [It has] a side console and a 15-gallon fuel tank. The engine is mounted three-holes-up on the transom.
I live in Alaska and often times we use our boats to haul ATVs to outlying island to ride, so I do haul a bit of weight at times. But ultimately [highest] speed is my goal.
Any input or general performance talk would be appreciated.