BF20 prop

Hi all just purchased a BF20 4 stroke, 03 model, test drive it yesterday after fitting to my 3.4 edgetracker, and found it a bit slugish, compaired to my orig motor which is a 15 johnson....the prop measures 8 1/2 inches across, it may be the original 4 blade prop (9 1/4) just worn down, what prop do i need to get the best proformace out of this motor, 3 blade or 4 blade and what pitch? it carries a 20l fuel tank and starter battery up the front of the boat to equal out the weight, as well as one person tiller steering, and one person up front (some times 2 but rare)
cheers Greg

Yes, that prop is much too small. We run that same outboard on a fleet of 36 21ft. Gregor rental pontoon boats that will see, at times, 10 adult load with accompanying fishing gear, coolers and patio chairs. In other words, a very respectable load for ANY 20 hp outboard. Experimenting with props available from Honda, we found the 10X9 seemed to allow for taking advantage of the engine's torque to get the boat moving and also gave the optimal top speed.

I suspect that the prop would work well on a V hull but a smaller diameter, as in the 9 1/4 you mentioned, might provide a little better top end on that hull.

The prop that comes with the motor is a 9 1/4 x 10. Usually the size of the prop is stamped into the one of the blades.

The 4 blade will help get the boat on plane. In general, though, a three blade will be better at top end and the 4 blade will be better to take off and control.

For an 11 ft aluminum v hull boat, the 10 pitch might hit the rev limiter. Unfortunately, unless someone on the forum has a similar combination, you will have to experiment and see which one works the best.

Just put a 20 with remote control on a 16 ft aluminum boat and it turned up to a little over 5600 rpm with a 9 1/4 x 10 prop.

Considering you generally have 2 people and that it is a tiller model, the 9 1/4 x 10 may do the trick.

Let us know how things work out.

Mike