So I got a carb from ebay off the 08 yz450f to put in my 99 400. now it wont start sputter or anything except its kicking back on me every few kicks. I cleaned the carb before installation and double checked the boots to make sure they were not leaking. the jetting appears to be stock with the exception of the pilot #48 and the main #165. the needle is 3rd position from the top and pilot screw is 2 turns out stock pipe in the california valley. could the larger jets be causing this problem? Maybe I need to use completely different jetting since im using the 400 motor?