Redflash the problem he would run into is he would have to completely re-design the kart. There is no way he can get down to the axle by going to a horizontal shaft if you look at the pictures a little closer. I do agree with you this wasn't a big seller for Carter Brothers but it worked and they saved on not using a clutch or torque converter but it was very complicated. Some engineer must have had a fun time with the design-- job security. I don't know how mechanical Robert is but to toss everything and go to a horizontal set up he would put a lot of money into the project where if he can get the friction wheel he is done. There has to be some other people out there with the same kart who could look at the wheel on their kart and get a number off off it. Carter Brothers bought the wheel from some one like Snapper, MTD, or Murray. I am "old" and I still fix things. and this is fixable the way it is. He just has to get lucky with a part number.