Its the fuel filter, its likely gotten dirt in it or old fuel and what have you, its gotten clogged up and is draining performance out of you king, happened to my 2007 450, my uncles 2006 700, i live in ottawa canada and there is a dealer here who knows a specific filter you can get from Napa, only thing is the stock filter is molded to the pump and has to be removed, but after that i think it even has mounting for the new filter, as its basically the same thing just isnt attached. The King Quad's one major weakness is that fuel filter, the littlest bit of muck gets in there and its choking. Their belts last forever. I have 11000ks on mine.