Do I read this right, you replaced a piston because it lacked compression, and you rode the bike with the new piston and now you have no compression.
Did you investigate why you had no compression, like doing a leak down test or even a plug chop to see if the correct jets are in the carb.
Did you do heat cycles and a break in proceedure on the new piston or did you just ride it?
The revving says to me that you you have an air leak and you have tried to mask it by messing with adjustment of the carby.