Hi, I have a VB1T 150 super, I changed the sparkplug last week (same mode of NGK), it worked perfectly for 3 days and then it begun to back fire, and impossible to start it again:
I cleaned the sparkplug (quite oily and black) but it sparks, then it look it very dry, she started again making a lot of blue white color then stop and backfire. when I remove the spark plug again, it still very clean even dry. I cleaned the Carb, but no improvement.
If I have sparks then it is not an electricity pb.
Thks for your advises