I am New to this forum and new to mud motors. my lil 35hp johnson is not cutting it anymore and i need a mud motor. i cannot afford buying one because just had my first baby. what i do have is a laser cutter, tig,mig, folding machine, cnc machine, and anything else that it would take to build one of these motors. including all the drives and pullys. my question is am i headed in the right directions with this drawing. so far i have only made the transom mount and there is some other things that i am unsure about, like the length of the drive pully housing. gear ratio for a 18hp kohler coomand engine, shaft length andtype of prop. i tried duck chat but had no luck the guy told me to start my own thread so i thought starting it here would be best. i plan on making everything out of 10 gage AR material. with the shaft housing being 1/4 inch wall dom tubing. machining my bearing housing. here is a drawing of my plans on the biuld. let me know what you think

Have you given any thought to how you will trim and tilt it?

yes here is the actual mount i have already made

That thing is going to be heavy. Forget the AR material, use aluminum on the belt housing and anywhere else you can. .250" thick DOM is overkill for the drive tube, .125" or .1875" is plenty. Start with a 1.5:1 reduction and a 10X8 surface piercing prop. You may be able to gear up to 1.3:1. Download the Gates Design Flex software from their website to help select the componets for drive. I like to stay with about a 30" length to the drive tube. Length of the belt housing will depend on the height of your transom.

Shoot me a PM with any questions.

what are you going to do about a pivot point?

note: why not angle the shaft and pulley? as in 4-6 degree's it would allow more movement of the prop and not as much fight to keep the prop in the water or on top of grass beds.

I have a set of drawings I been working on for past 6 months but they are much more complex with a considerably bigger choice of horse power.

i would like to take a look at those drawings, im pretty sure i can build it. i have all of the equipment neccessary. is the aluminum going to hold up to the abuse? what are all the big name motors made out of? i have aluminum that i could make it out of. but i thought i would make float pods to weld on to my boat with i get it all done. i dont have a boat yet, i sold my 16ft v bottom today to fund this project. i know that i want a 14-16ft boat to put this motor on. and i really think that with the float pods weight will not be an issue. i wanna build this thing solid.

i dont get how to have the drive shaft at an angle. wouldnt my belts slip off? how does that work?

yea thats what i was thinking about doing. i like the xpress drake boat and thats what im going to do. i wanna have a full 14 or 16 feet of boat to hunt out of so ill do the hunt deck. i am waiting on the motor its getting rebuilt and i need the bolt pattern before i start to do anything with this build. i decided to go with a 20 hp kohler command. now the rpms are governed at 3600, the same as all the other ones. what would be the advantage of 20hp rather than a 16hp? more power? more torque? not really sure..