ok im finally going to jet my raptor after forever. All it has is a fmf powercore 4 slip on and a pro design K&N kit. Where i live its about 80 degrees but getting colder
what you need to do is get a fresh plug reading and determine if your rich or lean and by how much. Then from there Id jet based on the results and go up a size after you get it right to comp. for winter and the cooler weather ahead.