For the past ten years my 1991 my john deere lawn tractor with a kohler engine. Will suck the throttle plate off the throttle plate shaft. With the screws making it to the muffler. (ya lucky) And the plate getting to the intake valve. Ether the screws would work loose or the heads would break off. Four years ago I soldered the heads of the screws to the throttle plate. That lasted two years till the screw heads again broke off. Today the rpm was getting a bit high. I took off the carburetor. And found the solder did not keep the screws from getting loose and going threw the motor. So I get new brass screws and soldered the heads to the plate. And cut the lawn before the rain. When done the rain came. But I did not want to have to fix this again. So take the carb back off again. One solder joint was broken all ready. So I resolder. Remove the throttle stop to get to the other side and solder the plate to the shaft and put some solder on the threads of the screws.
I have heated the carburetor a few times before with no problem. But this time I found that the choke lever shaft was not metal. It was plastic with a metal coating. So now I have a tractor, that dos not start well. But runs well after you get it started. Called john deere and yes can get a new choke lever shaft to mount the choke plate to for a kohler engine. But it only comes in metal coated plastic. I ask why just not make it out of brass like the throttle plate shaft, Got to be cheaper to make. Answer but the plastic saves a lot of time when putting the carb together and dos not have the same high
vacuum as the throttle plate.
OK so I look at new lawn tractors. Hay this one is almost 20 years old. New ones all automatics. Errr I like having a clutch. New ones have a this safty stuff that it make one think "dos it work at all". Then look at cash buy over loan. Ether way all I could see was less provider time. Time = $. The time to fix old over the cash to buy time. I ordered a choke plate shaft and then called a provider.