Tohatsu 9.8 prop change, HELP

[Teee-rible]

I recently bought a replacement prop for my 9.8 Tohatsu, went from the stock 8.5" Diameter X 9.0" Pitch three blade to a 8.7" Diameter X 7.0" Pitch four blade.
Needless to say I am experience major slippage and engine almost redlines!
I AM IGNORANT and a newbie. Anybody got any suggestions on what to do? I was looking for a prop to go faster, and this must not be the answer? Does anybody know if there is a good replacement for the stock prop that will increase my hole shot and top end speed? Thanks for any info and be gentle as I said I am ignorant.

 

[steelespike]

Re: Tohatsu 9.8 prop change, HELP

OK, do you have the original max rpm and speed and type of boat. you can't ,make an intelegent prop change without it.
Highly unlikely to get a prop to provide hole shot and top end.Like asking a car to cruise in 1st or 2nd gear on the thruway.
Disregarding specifics a 2" change in pitch as you did will add 400 rpm,and some hole shot.
A 4 bld generally helps low end performance at a sacrifice of a little top end.
Some 4 blds are designed specifically for heavy loads/ boats, pontoons and wouldn't perform correctly on a relatively light boat.


More info:
Just wanted to add the 9.8 is probably rated for about 21 mph under ideal conditions a boat that can get up on the water, light load/driver etc.
You might check speed with a gps then figure if there is any room for improvement.We can tell you how to get the most from what you have.