my toro nero is a real bear when i first start it up. it acts like it is super rich but runs good when it warms up. i run a od97t ,byrons 25%, 41021/9901, hsn 1/8 turn in from flush,lsn 3/4 turn out from flush, .6 mm idle gap, 6.5 insert @ 20 degree ambient temp. i don't think it is because of the cold weather because my plus 4 does not do this. any thoughts???