I have 7mm cub, pwk 33mm ( main:172 pilot 45 ) +5 timing,19cc dome, I run 3L of c12 with 7L of 91octane ( almost 1/3 ) and depending the temperature, sometimes the bike cuts a half gas, and sometimes at the top, I have try some sizes of jet and yet, the color of my plugs seems good.. and also, it looks like it gets stuck sometimes, it does so as always, but often enough and I don't know if my problem, is the jetting, fire, ignition.., stator.., Thank you for yours advices !