here is the deal. its a wr450, 3500', 70 degrees. There is no exhaust leaks, and there is an after market Dr d exhaust. Other mods are power now, air box cut open, and backfire screen removed. The needle has been raised a clip, the pilot has been brought up one size bigger and the main is 2 sizes bigger, the airscrew has been adjusted from 1.5 turns all the way out to 3.5-4 turns.Now of decel it pops like crazy. The pipe turns red hot from the cylinder and back just about to the connection with the silencer. The cases even get hot enough to boil water. If you spit right about the clutch side case it will boil.It boils over at idle. It is friggin hot!!!! Where do i go from here? its ryno66's bike but he refuses to ask these questions. Hes going to melt his bike!!!