Well it looks like I may have turned my happy time motor into scrap. A few months ago I decided to check out the wrist pin bushing because I got a bearing to replace it. I have done this before on my Puch moped and it was easy. Unfortunately it was like 20 degrees at the time and it turned out to be more difficult than I thought and I kind of used too much force because my hands were freezing. I thought I had it all ready to go and just "tapped" it a few times but apparently something was not right.
Now the alignment fins on the base of the jug are cracked. I was trying to install the piston from the bottom of the jug, I guess you are supposed to slide it in to the top. The aluminum is really soft. I didn't know about the ring alignment pins at the time.
I may still try to fit it in from the top, who knows I might get lucky. The sad thing is the bushing was OK, my bogging problem was probably carb related.