So yesterday I finally got my xr500 (dual-carb) running and driving after a month long top-end rebuild. I dropped in a weisco 10.25-1 piston (1mm overbore) also has a non snorkel airbox mod I went up 2 sizes on the pilot and and I believe 3 on the main jet circuit. I've been experimenting and the stock pilot jet seems to work the best but it has really hard starting. I'm just wondering if possibly main jets are small or to big causing the pilot to be off. Also the plug seems too rich but after I've been cranking on it for a while I see no fuel on the tip of the plug.