As bsyphrit has said, use plenty of PB Blaster and we are talking for a few days. Give it time to work in. I use a 1/4" drive ratchet an extra long length of Allen tool and a socket that would fit the tool exactly. I cut the length of tool till I was able to slide the socket and tool down till it is securely engaged into the set screw and then would use the ratchet to help apply a good amount of pressure and keep working it. If it didn't feel like it was going to break loose I would squirt it again with some PB and try again the next day.
As for never ending, that is why many of us end up either doing a good complete mechanical overhaul during the winter or as soon as we pick up our cub from a seller. There really isn't a whole lot on these little machines that cannot be fixed or repaired. A person just have to have some patience and time. I was never much on patience in the past, but these last couple of years and my refurbish of my 128 have really made me learn to take my time. Let us know how things go.
