I have been running stock pistons with toomey t5's, boyesen reeds, ported cages, dual k&n pods at sea level for a couple of years with my bike running perfect. My jetting was 280 mains, 30 pilots, needle clip next to the last bottom groove. With my new vito's super stock .20 over pistons and tdr reeds I am running lean. I had hard starts so I jumped to a 32.5 pilot jet and solved my starting problem and smoothed out idle. My top end screamed but plugs looked lean so I jumped to a 320 main. Now I'm having trouble trying to get the mid range right but I've been raising the needle clip. Do I need to go down a size on my mains to get mid range right. Sorry about the long post just trying to give all the details.