honda 150hp, and 16p prop

[lippa]

anyone have the above combo? im running a 17x 14 1/4 seriously considering a 16 x 14 3/4

just interested in some performance figures.

thanks

lippa

[FNQCairns]

Why? on the surface it looks like you plan to tow a barge with those new props, keep the 17p and to reach the revs you want/need go down in diameter, if the quite average honda props (solas?) cannot cater, buy torque flo hubs and fit mercury.

cheers fnq

[Redrocks]

Lippa,

I have a similar issue with mine. I have a BF150 on my Sig 600RF with 15 x 17R and will be going down to 14 3/4 x 16R. I only get about 5600rpm and 34knots. I am not so worried about top speed, but the holeshot and an increase in economy are big factors. I like an outboard to be propped so it reaches maximum rpm.

What boat have you got your 150 on?

Let me know how you go.

Redrocks

[lippa]

on a 6mt plate boat mate, my figures are near on identical to yours
i cruise at 4500rpm for 25 knots 28l/phr

both Garry (Spaniard king) and solas Steve have suggested to try 16p prop.

was hoping someone would have figures on it.

fnq, my current prop is a turning point POS. and i dont think ill ever get too max rpm with any brand 17p. i have 14ft tinnys with 30hp's fly past me! lol

[Redrocks]

fnq, my current prop is a turning point POS. and i dont think ill ever get too max rpm with any brand 17p. i have 14ft tinnys with 30hp's fly past me! lol

The pitch is not relevant to the horsepower of the outboard as each brand has a different gearbox ratio. For example, I think the solas prop for a 140 suzi fitted to a 600RF is a 13 3/4" diameter MAXIMUM, with from memory, 21"pitch (don't quote me, just trying to remember what Steve emailed when he thought I had a suzi.)

So this tells me, Suzi have a different gearbox ratio. The Honda is swinging the 16 inch diameter for similar performance (albeit with 10 extra HP), but only 14"pitch. The prop size and pitch is, in reallity, a gear ratio.

[FNQCairns]

Lippa assuming you reach 6k now with the 17p you will be travelling near or up to 64km/h if you swap to the 16p at 6k = 60km/h.

Not so fine for fuel economy or for cruising speed which is a function of your WOT speed.

You can turn it around, as stated above the prop can be considered as part of gearing...but only the pitch component, the diameter is resistance to turning as is the cup and total surface area.

To bring it all back on track keep the 17p and drop diameter, not knowing what yours is doing is hard to help properly but every 1/4 of an inch you drop in diameter will give you extra rpm and because the pitch has stayed the same also extra speed. You will loose out everywhere with a 16p and increase diameter.

Prop sellers only sell what they have in stock, square peg into a round hole is ok if it get it out the door. you can do lots better.

17p 3bl with a low diameter..say 14 neat .18p 3bl with a very low diameter..say 13 3/4 I am guessing here as I do not know how many rpm you lack but the relationship speaks for it's self.

4 blade props will do you over every time.

Turning point are ok it's all in the application.

cheers fnq