2002 SV650S. Bought it used with 4,000. Put 700 since. I was riding the other day and had in 6th gear in lower rpms and gased it to get in traffic. Started to sputter and rode home on 1 cylinder. Pulled plugs, rear one foulded out. Pulled Carb and found a small spring out of its location with o-ring fragments inside. Replaced O-Ring put carb back together and put back on bike. Put another new NGK plug in. Started right up and foulded out again. When I pull the plug, its not wet and its just burned up. The carbs have been rejeted becuase it has an after market pipe. But why would this have been caused with me throtling it in to high of a gear? Any ideas??