Hey Guys! Hoping you can help me. I have a 2003 Sportsman 90 that im having issues with. It idles and runs great. You can run it full throttle and it zips until you let off the throttle, when you jump back on the throttle, it bigs down and will either stall out or just bog and you have to give it a second before you can go again. To me it feels like its starving for fuel after its run WOT for a minute. I rebuilt the car and im still having the same issues. Stock sized jets, replumbed the whole fuel system including vent lines, new fuel filter. Still cant seem to get this thing running. Any help would be appreciated. Thank You.

 

Try doing a compression test.