RTX running really rough!

[legend]

2006 RTX has 6000 km on the machine, has a ulmer clutch kit and airbox mod 144 studs and 1 1/4 track. Was running great most of the season and in the last 2 weeks sled has gone wrong way last week true 170kph on gps and this now 137 and backfires really bad when decelerating. It sounds like an injector problem pumping in way too much fuel but cannot figure it out???? Any possible solutions????

 

[gsxr]

put a can of seafoam injection cleaner thru it !!!

 

[Yummy]

Exhaust leak. Probably the front exhaust has give away. Happen twice so far!!!