Guys, I am building a pontoon that will have a prop on it for duck hunting. It will need to go through all the junk that everyone experiences duck hunting. I will run about 65 hp and I need to make a shaft for the prop.

My question is this...what type of shaft will have the most selection for running a mudprop? I am talikng about Hex, straight shaft maybe 3/4 or 7/8 in in diameter with a Key, or shear pin? If using a key or shear pin, where would you place the hole in the shaft? If using something else, could you give me some specs on how to build the shaft at the prop end?

Thanks

Mark

Is this for a water cooled engine? If so a good prop prolly aint gonna do you a whole lotta good. Yeah the prop may be able to churn some mud and cut through some veggies, but the water pump is gonna be sucking up all that crap your churning up. Soon as that water pump gets full of mud or grass your engine goes KABOOOM! We rebuilt a shit load of outboards before turning to the air cooled engines.

If you are going to go through with it. I would not use a shear pin. I would go threaded with a lock nut to hold it in place. And it shouldn't matter too much what shaft you use. You can get a prop built to fit just about any shaft. If your looking for stock props, MB sells either a hex or 7/8 thread. I don't know off the top of my head what all the other manufactures sell. The size shafts aren't listed on the website.

Go Devil sells there shafts for $50.00 and they are threaded. Then u could cut it to the length u want. Just a thought!

Quak,

I had emailed GD today and they said that they do not sell props to anyone who doesn't have their motors! lol I was a little surprised to say the least. I am thinking a 7/8 or 3/4 threaded shaft but I don't know which is the best way to keep the prop from spinning on the shaft. Any ideas? or who to talk to that has stock props?
mark

so call them and say you have a GD motor.......

Mark,

The shafts are threaded, but they are left-hand threads. The prop will not spin off the shaft. Everytime you hit something, it will actually tighten the prop. You just put a nut behind the prop, but from what I've been told, it's mostly to protect the threads from getting boogered up.

To buy go devil parts you need a frame number. Go devil props are shouldered out on the end of the threads and the manual says to double nut it on with a little play left. I don't know why bu that's what the book says.

If you do buy a shaft from go devil tell them you want a nut kit with it. That will be all the hardware you need to install the prop.

Am I the only one scratching my head with the thought of him buiding this "mud motor" on a PONTOON boat? How do you get a pontoon boat unstuck?