I have a drive shaft which I had made but it's not straight and I need to make another. It's for a 9hp diesel engine with a lot of torque for a 9hp. What should I make the drive shaft out of? I needs to be 1" or less in diameter.
Thanks!
Greg

Where are you getting your prop from?

The industry standard is a 3/4" 10 tpi threaded hub on a 3/4" shaft with a keyway in the u-joint end, that will hold up fine.

I have a Hopkins Propeller MB1 but I really need the MB11 I believe.

My motor runs a straight shaft, no u-joint.

And my prop goes on a smooth shaft with a shear pin.

But what is the shaft itself made of? That's what I need to know. I need to have one made here in Venezuela. You can see the motor at http://gregihnen.me

Go devil uses carbon steel

I typically use 3/4" 17-4 H1150 or 4140 Heat treated turned ground and polished. On a 9 hp you could probably get away with using cold rolled 1018.

i fished there in the past .... what a wonderful place... i would use 3/4" hot or cold roll steel... look at support races on metal buildings ... if memory service me they us that size too... good luck

every drive shaft on every mud motor made here in the states is a solid shaft, 3/4" for your application. 4140 stainless is common, cold roll steel will work and does for home builds on the cheap. with as many stumps/logs as you encounter, I would go with the solid shaft, not a tube. get the stainless if you can.