Hey guys got a 600 grizzly that runs poorly. When he first brought it in it wouldn't run at all he just rebuilt the motor (new rings and piston i think) anyway i did some looking went through the carb and it was shot put the new carb in then we lost spark and found that the CDI went bad. now it runs and idles well but as soon as you give it any gas with the choke on or off it sounds really loaded up and will die. tried tuning every different way different jets different positions on the needle different turns on the mixture screw and still the same issue. I have check timing (its all good) i replaced the spark plug i replace the stater and pick up coils i checked compression (it was good) i hooked a timing light up to it and we are not loosing spark through out the rpm range I also unplugged the brake sensor i heard that can cause some of the same issues i am running in to and still no change with it plugged in or not.I went step by step from the book in the troubleshooting steps. I am really stumped. Could there be a flat spot in the cam??