Had an 850 converted to E85 finally got to the track on sunday.Had my regular gas carb on for first pass ran fine. Put the E85 carb on drained the race gas and filled it with E85.Had a whistle in the carb thought it was a vacumn leak. We sprayed it down with starting fluid could not find it. You can hear it coming thru the pits even.I can hold my hand over the right venturies and it will kind of block the sound.