Thanks. I called the carb shop. They have a minimum order of I think $90, and then a new MR would be another $70.
So, after reading a few threads and seeing that adjusting the MR height is common, I will try that.

I did take off the carb and set the float height... it was way low (about 1"). If it ran rich that way then I guess the MR must really need lowering. Going to do that by just taking the top off.

I have a question for anyone who knows (Carb King??): My Carter YF choke doesn't seem to really go fully open- on the rear of the carb there is a coil spring that keeps the choke turned about 15 degrees toward closure. Is this normal position during warm engine driving? I can push it filly open with my finger but it springs back that 15 degrees or so.
I guess the spring is there for a reason. There is a linkage that goes from the choke and coil spring to the throttle linkage, but it doesn't seem to affect the choke.

Can anyone tell me what that coil spring on the choke is for and wether the accelerator is supposed to be able to counter its effect?

Thanks.