first i am at sea level ,390 mains ,30 pilots,40/1 mixture,and plug still reads lean, i cant get the it to lanch (pavement) it revs good put as soon as the clutch is out bogs for a sec then goes and pulls good . NEW MODS ARE noss head,21 cc domes,comp.150, ported stock cyl. boysen rad reeds, stock gearing 14/41. 22/11/9 tires. the plug looks a pinkish color.any help welcome . it does good on dirt but still reads lean.the exhaust tips on my t5s, are dry .possibly wrong mixture u think. :biggrin: