I started up the Rocket today and gave it a few revs and all the sudden I heard a pop come from under the seat and it felt like I got flicked in the arse. Anyone else experience this?
How many miles you have on the bike? When I first got mine I got the same thing. Lasted until about 2500 miles then tapered off. It only happens occasionally.
I remember posting a similar question as yours when it started happening on R3Owners.com and the explanation i got was that it was common and would fade away as the bike got worked in.
My theory on that is that your bike's ECM has an Eprom learning feature and low mile bikes haven't yet "learned" your riding habits yet, and are operating on a set of default fuel maps that you may be over taxing by aggressively blipping the throttle and backfiring through the intake blowing you off of your seat. This may re-occur after doing the " 12 minute tune".
With 19k behind me, the beast still farts on occasion. I recall it was a bit more frequent when she was a lot younger. As Tomo remarked on, it seems to occur with the occasional blip of the throttle; and, for me it's on low speed decel condition.
Is there a chance that you bumped the throttle between the time that you turned the key on and the time you started the engine? If you turn the throttle grip or bump it during this initial start-up procedure it can mess with engine running set-up/air fuel mix. RADEMIS