I think the oil problem has been found,77 I had asked what type Fuel pump not carb type,If it's mechanical may not be supplying sufficiant fuel on big end cousing your lean condition conferm this first then look at jetting.may have to switcth to electric pump with regulator.If this is the case then you can play with jets,what size carb spacer plate do you run the thicker the plate the leaner the signal 1in 2in ETC.Do you run A hood scoop with out A air pan?