I decided to go back to a 3 shoe clutch but I didn't have a flywheel removal tool. I stopped by the LHS and asked them to put on the new flywheel. A few minutes later, the mechanic came out of the back room saying the piston head on these cheap engines are too thin. I guess they used some other tool to keep the piston stationary why putting on the new flywheel. The piston head was all caved in.
Anyway, they gave me a Sirio .30 for $100 to make up for it. I am kinda sad to see the STS go, it looked like it was about to get good. Oh well. How much for an STS .28 piston and sleeve?