Lm18 tohatsu 50hp prop recommend

[Edd]

I’ve got a new tohatsu 50hp short shaft to repower my lm18 ( had a 30hp Suzuki )

Any recommendations on which prop to start with? The tohatsu doesn’t come from the factory with a prop.

[TomW1]

Hi Edd would be glad to work it through my prop calculator as I have done for many others. Just get me the weight of your boat as you sit at the dock ready to launch for the day. Make sure you include everything including lunch and the beers. No need for the motor as I have the Tohatsu's in my files, nice little motors, should last you a long time

I had a thought and went back in my files to see if i had done a LM18 for anyone else and adjusting for your 50HP I come up with 11" diameter by 15.78 pitch on a 1600lb boat. But to be accurate let's do the weight of your boat.

Tom

[Edd]

Thanks

I haven’t put it on a scale yet so I don’t know the exact weight. But your recommendation is in line with what I’ve read on the micro skiff forum. 11.1 x 14 is what others have used on similar boats. I figured I’d start there and with aluminum before I invest in a stainless prop.

[TomW1]

Great Edd when you go to an SS remember it is more efficient so you will need to increase pitch by 1 for the SS so increase to a 15.

Tom

[Edd]

Update, I purchased a solas aluminum 11.1 x 14 . I’m still breaking the engine in but during the 1min full throttle runs I hit 33/34mph at 6k rpm.

[Fuzz]

Did that feel like you were flying? How did the boat at that speed?

[Edd]

Did that feel like you were flying? How did the boat at that speed?

It’s feels fast but the boat is very stable and it runs perfectly straight with no tendency to pull left or right at all. I have the Bennett spring loaded tabs on the back and there is zero porpoising instantly planes off

[cape man]

Did you go three or four blade? In turns, and running shallow, my switch to a four blade was a game change.

[Edd]

Did you go three or four blade? In turns, and running shallow, my switch to a four blade was a game change.

It’s an aluminum 3 blade, I wanted to start there before investing in a stainless or 4 blade. The prop is fine but the engine is sitting a little high the cav plate is almost 2in above the bottom. I think dropping an inch or leveling it will make a difference. I don’t want to cut the transom so I’m trying to figure out a solution.