I don't know about yours.
But, mine has reverse that utilizes the cam shaft.
Those engines are NLA.
So, if you replace the origional engine you will give up having a reverse gear.
You must have a different model TB than a Horse.
I think what he was getting at is the shaft is different, I see what Joe means now that I replaced it. The Kohler shaft was tapped for 3/8, the HF motor is 5/16 so the reversing disc just spins because the hole is bigger and won't reverse. Only way to fix it is to make the tapped end of the HF shaft 3/8 or weld the head of the 5/16 bolt to the reversing disc so both have to spin. Not a real good option if
You ever have to take it apart again. I'll live with it for now. As for the old Kohler I still have it, didn't junk it. The carb needs rebuilding (my buddy let it sit with gas in it for about 2 years) it needs a new condenser, needs rings and the valves adjusted. If I'm gonna do all that, I might as well do a full rebuild, so I opted to put the HF motor on for now so I can till and cultivate this Spring, and it only cost $99 and I'll have spare engine later on I can use for a wood splitter or pump or whatever. I think a rebuild kit is about $80, plus $35 or so to have the engine parts dipped and get all the junk cleaned out, carb kit is $25 or $30 too, so for now I was time and money ahead, but you can't beat those old cast iron Kohlers so like say I've still got it, plan to re-use it