Tohatsu prop identify

[Mikey1982]

Hi all, I have a 40hp Tohatsu 2 stroke and struggling to work out what prop I have, the only markings I can see are 12.5 and "C" on the back of the blades, any ideas would be greatly appreciated

[Locozodiac]

Is that a 2 strokes, 2 cylinder MC-40 motor ? What do you want to know about that prop, plan buying a new one, need a better water performance under load ?

Happy Boating

[Roflhat]

Sounds like a 12.5 pitch prop, you can measure the diameter easily enough

[Locozodiac]

That 12.5 pitch prop must be Jurassic, there's no half pitch sizes available in the 11 to 12 pitch size these days so might as well go for the full 11 pitch size, motor will rev slight higher. Ideal would be to dial a prop that can power the bot/motor combo betwen middle to max wot rpm factory stated, will need to install an induction tach and test under a wot run on flat calm water cond as loaded.

Happy Boating