Just purchased a 2013 XTZ 1000 and it smokes under a load but not at idle. I know it is fuel because of the smell and it makes my eyes water in the cab. It has a speedwerks slip on. The engine runs excellent and has plenty of power just running rich. I changed the plugs and they were black to the point of appearing fouled. I also checked valve lash and it was fine. I have done some reading and see that it may be tied to a fuel pump/regulator or injector issue?? Any help resolving my issue would be greatly appreaciated.