im trying to dial in my 40mm lectron carbs just burnt up my cub cylinder so i don't want to do that again mods are 7mill stroker with 68mm pistons cool head with 19cc domes port and polish trenched and epoxy case im in Utah @ 4300 feet elevation my needle where @ 51.05 mm and im thinkin some where around 50.05 ???? any help is appreciated