Klotz r50 at 32 to 1 . I share the gas with my boys yz85 and ktm65. I mix it at 32 to 1 for the small bikes. My 500 runs great. Stock needle second clip, 48 pilot and 165 main , pro circuit 296 sil. fmf pipe,reed spacer, 3800 feet . I could even get away with a 162 main . I like it a little rich. The 296 really changes what jet the bike wants.