Bike not running so good

[AndyM]

03 Tiger with 40k miles on it. Lately the gas mileage has gone down to the mid 30's. Light used to come on at 200-210 and now comes on between 180-190. Bike seems to be running a bit rough at idle.



Valves are in spec. New plugs. Clean air filter.



What else to check? Throttle body sync? Can a dealer do a diagnostics check from the computer?



Thanks.

[NortonCharlie]

might be the oxygen sensor acting up.  Tends to make it run rich.

[AndyM]

might be the oxygen sensor acting up.  Tends to make it run rich.

I've had an 02 eliminator installed for the past two years.

[JRO]

I've heard a lot of arguments about how O2 eliminators don't really work.  



Just something to consider.