Greetings, I've a stock WR450 with the basic mod's. I spoke with JD Jetting directly when I purchased their kit and they were pretty insistent about using the stock 45 pilot jet with their kit - for my environment. 0-1000 feet 60-85 degree's I've recently added a YZ muffler and now I'm wondering about that 45 pilot jet again. It seems from all of my searches that the most common usage after modifying stock WR 450's is to go to the 48 pilot for my environment. I understand that only experimenting will tell for sure but my bike does seems to run great with the 45 I'm only a bit concerned about running lean while on the pilot circuit. Thought? Thanks!