- Feb 26, 2017
Mine correspond including size of new jets.According to Roy Bacon's Norton Twin Restoration: 850 mk2a option for 74 would be 220 mains. The carbs should be stamped R 932/33 and L 932/34 My 74 850 Interstate had 260 mains but when I changed the cam(Megacycle) required 270 mains. My guess and Onder's is that the floats are influencing the needles during riding.
You mentioned “floats influencing the needles during riding”.....as in opening too much or simply allowing an irregular/unpredictable flow?