Registered Forum User
Ducati Corse
Posts: 3,134
Join Date: Jan 2002
Location: notts
Mood: Bloo and Yellow.. and Red now ;)
a back fire is usually indicative of a weak mixture.
Fitting open cans would also lean the mixture off to.
If the bike was set up with a CO meter during the service, then they could have set it to factory specs, which is about 1.5% CO or less I think. I seem to get best results, especially with cans fitted with it set at around 4%.
If the throttle sensor was reset, that could have an effect to.
Worth mentioning the backfire to them and have them recheck or adjust the mixture for you.