Yes thats part of, it my western does have a sdc 80, and the throttle shaft is really bad on it but runs too good to mess with, I'm using it daily so I'm not pulling it apart.
Update: I think my issue is PO ran really rich mixes and rich fuel loads, I'm leaning it out every time I run it today, its REALLY starting to come alive, I think there too much carbon on the combustion chamber, the exguast wasn't too bad but entire insides were kinda brown/black including piston, muffler, plug. Its running MUCH MUCH better now and its letting me take the screws in a 1/16 at a time now and likes it, idle is improving greatly without smoke now. STARTING TO PULL HARD!!!!!! 24" full comp in 30" Maple is easy now.
I'll give it some time to clean out now.
Duane
It's possible the rings may have been a little carbon stuck and now they're freeing up. Sounds like you got a good one.