Yam f60 prop size question.

[bar raider]

I have a f60 on a seajay territory 4.55 tiler and I want to change props. 95 % of the time the load is 2 people gear and minnkota and battery's. When I do this with the current 11&3/8x12 prop I get 6100 rpm wot and when I'm alone I have hit the rev limiter. Top speed 58

Do you prop knowledgable people recommend 1 size/inch or 2? I'm thinking two, may as well make it worthwhile. Wot range in manual is 5000 to 6000.

Apart from getting the wot rpms down I want to get a better speed at cruise 4000 4500 give or take for running up the pin from the goldy.

Thinking of going genuine yamaha caus it's cheap and across the road (new dealer)

The aftermarket prop sizes I've found reduce in size when going up pitch is this normal?

I'm having trouble finding genuine yamaha prop part numbers and sizes. Does anybody know them?

Thanks all. sorry about the many questions I've not changed props before.

[Dan5]

Sounds like you have a good prop on now.....you don't want to drop WOT revs by the sounds of it....6100 is only 100rpm high which you should manage with the throttle IMO........I had a 4.5 Bluefin with the 60 and ran a 13p it was a tad slow from the hole but would reach the rev limiter at around 6300rpm from memory......it sounds like you are on a good thing already IMO.

Dan

[Towie0]

I cant tell you what rpm im doing but i switched my F60 prop to a 11 inch G Yammaha prop from the 13

I have a 4mm plate tinny 4.5m all the usual stuff that makes it heavy & it was taking a 100mtrs to get out of the water.
Now with the 11 inch its like a ski boat straight up on plane.

Do not quote me but i think from memory each inch is 200rpm change on motor.
The factory number was something like 11 3/4 x 11-G.

[Rip it up]

I run a f60 with two props.
A 13" and 11" on a 14ft glass runabout.

The RPM flutter on the limiter with one POB in the boat. But the computer won't let it run above the limiter. So i floor it out of the hole. Trim up into maximum efficency then back off the throttle to let it drop to 57-59 on the tacho.

With the 13" I max out at 5700 rpm. With the same load in the boat.

Both aftermarket Aluminium props.

I am seriously considering the stainless option somewhere in the middle. 11/12".

I do not have a cruise RPM. It's either 5700 & above or idle. Used in the estuary systems chasing crab pots. Chews lots of mud at times and still purrs like a kitten. 1800 hrs as a crabbing motor.




Damo's dodgy boat building factory.