spark plug color tuning

  1. M

    Help judging Spark plug

    Hi Any 2stroke wizards could help me judge this spark plug? It has been driven whole throttle range. It is a NGK B6HS on 50cc HT engine with needle on second position from top and standard jet (unknown size). It has been around 20-25 Celsius lately and I'm using 24:1 synthetic oil and 95...