I have a 15.5 fiberglass bow rider. Total loaded weight with me in water is around 1400-1600 pounds.
It’s got a 50 HP Mercury Bigfoot with 2.31-1 ratio? Prop is a 3 blade 13.25x15p. Also tried a 13.25x19p which is too strong a pitch.
The 13.25x15 idles/trolls at about 2.5-3 mph, and top speed is around 30 mph via gps.
however the engine only turns 4000 rpm, not the recommended 5000-6000 at WOT.
the 19p trolls more like 4.5-5 mph, and has identical top end.
Mercury seems to recommend 13.25x16p, stainless steel, which only they make, and cost is high..
so questions- What prevents the engine getting to top rpm? I don’t think 15p is too high. Engine Mount height is good, power trim works and has minor impact on top speed, throttle operates correctly and goes to full open, boat hull is smooth and clean, keel is flat. Boat planes and runs well.
is a 4 blade a good option. Should I expect any higher performance or am I in the ballpark for boat size and weight and engine combo?
thanks!
It’s got a 50 HP Mercury Bigfoot with 2.31-1 ratio? Prop is a 3 blade 13.25x15p. Also tried a 13.25x19p which is too strong a pitch.
The 13.25x15 idles/trolls at about 2.5-3 mph, and top speed is around 30 mph via gps.
however the engine only turns 4000 rpm, not the recommended 5000-6000 at WOT.
the 19p trolls more like 4.5-5 mph, and has identical top end.
Mercury seems to recommend 13.25x16p, stainless steel, which only they make, and cost is high..
so questions- What prevents the engine getting to top rpm? I don’t think 15p is too high. Engine Mount height is good, power trim works and has minor impact on top speed, throttle operates correctly and goes to full open, boat hull is smooth and clean, keel is flat. Boat planes and runs well.
is a 4 blade a good option. Should I expect any higher performance or am I in the ballpark for boat size and weight and engine combo?
thanks!