686 rappys are just toys when coming up against my 440 in the sand!!!same thing w/all piped and jetted bikes included banshees just like speeddmn said...get a wiseco 440 kit and go from there...[img]i/expressions/face-icon-small-happy.gif[/img]...send the head to curtis sparks....get a hot cam stage 2 cam....titanium valves and retainers....valve springs....stroker crank....fcr 41mm alky carb...and you will be set...

 

cals 400ex only thing iv'e done is put a fmf head pipe power core 4 muffler k&n dyno jet kit when i go racing i comepletly remove air box makes a difference.14 tooth front sprocket 18 inch holeshots mxrs.wanting to get more top end pull for racing & sandriding. when i get ready to do the top end thinking of going to lrd for a new pipe.

 

ds650, you recommend the fcr 41 over the 39?