My bike is used at 4000-5500ft alt. Mods: AIS removed ,baffle out, snorkel intact ,grey wire not removed and was jetted with a NFLR needle 48 pilot and 152 main . Bike ran fine with this jetting. I replaced the main jet with a 158 main as I felt the bike was a bit lean on the top . It's a bit harder to start now??? Makes a bushhhhh sound almost as if backfiring if kicked when cold , when hot and kicked it starts 1 st kick . E start spinns twice and then the backfire sound and imediately starts after that . This Bhwissssss sound was not present with the 152 main jet ? Anyone got an idea?