i have a 93 xlt sp 580, havin problems with gas fouled plugs. i just bought this 2 wks ago, it ran then, since then i have drained and cleaned the carbs, then it would fire up and ran perfect, but now, nothing. should i use a hotter plug? right now i am using ngk br9es, anything better? or is it that its just too warm right now? any help would be very much appriciated.