I just got to ride my 400 for the first time tonite. It has a huge dead spot if you pin it from idle. It starts great and runs good on top, but if you hammer it open and leave it there it will die completly. If you roll it on gradually it runs good. It ha s yz timing gray wire and a white bros pipe with no discs. Could it be maybe the pilot plugged. I haven't had time to take the carb off yet. Thanks for any input.