So I just rebuilt the top end on my 09 150sx I've done this myself 2 times prior. So putting it back together wasn't hard but not super easy either. The rings on the new piston weren't springy they were kinda notchy and really hard to clamp together in the rear and the cylinder didn't slide down over the piston very easily. I figured this was due to a good snug fit. Got her all put back together new gaskets and all. Kicked it over to start the heat cycles and it started for maybe one second if that andnow it feels like there is no compression in the kick starter and it won't start. I know for sure the piston isn't in backwards they only thing I could think of was the rings being upside down?