windowed piston

Kind of lost as to what’s going on, I have a reed valve + windowed piston on a 80cc 2 stroke engine. I’ve got an HP carb with a #70 jet installed. I can ride the bike and when I first start riding the idle is fine but when I get it going to WOT and then come to a stop the idle is really high. I...

So I’ve got a 66/80cc Chinadoll with a stock piston that I’ve windowed out like LA HoverBikes just to a curtain point I liked within the casting, a 2 inch miaowa reed valve kit and an HP carb with a 80 size jet installed. I’ve got a range of #50-85 I’ll say this as a start the bike ran pretty...