Yamaha Prop selection

I am in the market for a new prop for a 2008 Yamaha F90TLR and teh current prop/motor has no markings stating the current DIA/Pitch.
Looking on line there are several different options. How do you know what to buy...

Options are:

Diameter	Pitch	Rotation	Part Number
14	9	R	9411-140-09
14	11	R	9411-140-11
13.75	13	R	9411-138-13
13.5	15	R	9411-135-15
13.25	17	R	9411-133-17
13.2	19	R	9411-132-19
13.2	21	R	9411-132-21

Any suggestions on which to start with. WOT 5500 RPM, boat is a 2008 G3 1860 center console .

That is very unusual for a prop to have no markings at all. Take it to a prop shop and they can measure it for you.,

Mine is 17x13.5. WOT is 6000 @ 41.7 GPS. G3 17, F90 4 stroke.

Only thing stamped on the prop is 63863

41.7 GPS that moving so I ordered a 13.75 X 13 pitch - it I thought that didn't sound right when I made the order

Quote:

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Originally Posted by Wade2131

41.7 GPS that moving so I ordered a 13.75 X 13 pitch - it I thought that didn't sound right when I made the order

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That prop is too small you need to 13.75x17 pitch. The other user wrote his pitch first and diameter 2nd.


Edit - last week you indicated your original was 13.75x13. Is this a pontoon? If you are using a 13 pitch your boat will never hit 41mph. Boat speed at 6K rpms will be like 28mph tops

I would call Yamaha and see if that number means anything to them or call a well known G3 dealership and get their opinion.
I’ve never seen one not stamped either.
Once you buy it,it’s yours no returning it.
You can go on Yamaha’s website and use there prop selector but you still won’t know if it’s the right one.

So now I see the bottom of your post that you have a 1860 G3. My buddy is running a 2070 Lowe (similar boat only bogger) and he just had a 2023 Suzuki 90 put on it. He is running a 16 pitch power tech prop from his old 75hp and he is hitting his rev limiter. He is going up to a 17". Based on this I would say NO WAY you were running a 13 pitch prop.

Well I took the old prop to the Yamaha dealer, and it is 13.2 diameter by 19 pitch. So I ordered a Mercury prop with the hub kit to prevent any future prop shaft damage. "BOAT" sure means "bust out another thousand", cause I spent $1,049 for lower unit repair and new prop :(
Thoses were some expensive crappie that day lol

A 90 will generally swing a 15-21 pitch depending on the size of the boat.

My boat is pretty small for a 90hp (17' Tracker) and has a 21, which is almost too much. A 19 would be better if I ever ran heavily loaded.

Have you looked at the back of the hub for the size? some are marked there.
https://cdn.shopify.com/s/files/1/05...g?v=1635918837