wmk0002
Well-known member
What would yall consider to be expected prop slip for a lightly loaded, riveted 1648 flat bottom with a 9.9 or 15 hp motor? I'm asking because I have this boat paired with a 1982 9.9hp Evinrude and am seeing prop slip anywhere from 20-25%. This is based off inputs of 5400 max rpms, 2.42 gear ratio, 10" pitch prop, and top speeds of 16-17 mph.
You can see the exact boat in the link in my signature. The previous numbers listed came from a load consisting of me at 170 lbs, 6 gallons of fuel, group 29 battery (placed up front), bow mount TM, front pedestal seat/hardware, and a removable rubber floor at maybe 70 lbs.
I understand it is not an exact science due to the number of variables, but I would like some input on if my slippage numbers are probably typical for my rig or not. I plan to do all I can to make it better including adding a manual jackplate to raise my anti-vent plate as it is an inch or so below the bottom now, converting the 9.9 to a 15hp for more rpms which may help get on plane better providing better efficiency, and re-propping as necessary.
You can see the exact boat in the link in my signature. The previous numbers listed came from a load consisting of me at 170 lbs, 6 gallons of fuel, group 29 battery (placed up front), bow mount TM, front pedestal seat/hardware, and a removable rubber floor at maybe 70 lbs.
I understand it is not an exact science due to the number of variables, but I would like some input on if my slippage numbers are probably typical for my rig or not. I plan to do all I can to make it better including adding a manual jackplate to raise my anti-vent plate as it is an inch or so below the bottom now, converting the 9.9 to a 15hp for more rpms which may help get on plane better providing better efficiency, and re-propping as necessary.