Hi BB I hadthe same problem with my 2007 speedmaster...heavy backfiring evey now and then the dealer said it was a 'characteristic' of a carb model and same as all my complaints from purchase fobbed me off. Backfired one morning and blew the air box to bits.The cure was a pair of DNA pods and a Firestarter from Mike at TTP and no more probs plus more get up and go and fun riding so screw the air box and go for the other option. Regards Horse.

Last edited by Horse; 07/13/2018 4:37 PM.