Need some input here... 2012 XR650L, bone stock engine, exhaust, intake (EMGO 12-90450 air filter). Current jetting is stock, 50 pilot, 152 main. Location is at 5,000 feet altitude, temps vary from cool (mid 60's in the morning) to 80 mid-day for the summer, 30's in the morning to 60's mid-day for the winter, on average... Very low humidity (15% typical)... With the Clymer manual, I get a correction factor of around .95 shooting down the middle for temps. I BELIEVE I am running somewhat on the rich side, plug looks fine. I'd like to drop a 150 main in there during my next valve adjustment but the factory manual states that "operation with a high altitude jet at less than 5,000 feet may result in engine damage". Anyone here running a 150 main in conditions similar to mine? Any thoughts on attempting this before I leap?