2001 my bad the other post was wrong year Honda cr250 put new gas and plug running 40:1 tried racing fuel made it worse so I went down to mid grade fuel got a little better. Every thing is stock. Bogs at high rpm and lurches at low speed. Idle sounds like its puting around just to stay on. I am thinking its carb thinking of getting the kehin carb prejetted from carb part warehouse on ebay.