please help - 03 R6 problems between 4000 and 8000 RPMs
hey guys, some help diagnosing the problem would be greatly appreciated.
problem: i have had my 2003 R6 since january 2011 and it's been my daily driver since. i recently noticed that when my RPMs are between 4000 and 8000, the bike feels jerky / hesitant. it feels almost as though someone is constantly letting go of the throttle a bit, and then opening it, and letting go repeatedly. i have been riding for 3 years with my bikes being my only transportation, and ive had this one since 2011, so i know its not my thottle imput causing this. any ideas on what to check???
what i have done so far: i have been keeping up with the oil changes every 4000 miles or so. i always put 93 in at the pump, and a little injector cleaner every 4th fill up. i keep my chain well lubed, and just last week did a 520 conversion with stock sprocket teeth, so new chain and sprockets. i also have a BMC race air filter, and a hindle slip-on exhaust. power commander III with the map for a hindle slip-on with aftermarket filter. new NGK spark plugs 3 weeks ago, and checked to make sure i have the new coils (not the recalled ones). i cleaned my TPS (throttle position sensor) 2 days ago, so the throttle is a tiny bit more responsive, but the jerky/hesitation is still there and has been for about a week now. i also followed the how to thread on synchronizing the throttle bodies (so monometer is built and carbs sync'd). they were pretty far off, but they are now within half an inch at operating temperature. i also checked the engine diagnostics after i cleared them, and they are clean.
possible causes?? : i am taking my bike for a valve adjustment next week, since it has about 42 000 miles. could this be the cause?
i have also read that it could be the fuel pressure regulator, in which case i am going to buy a used throttle body and airbox from the 2005 R6 and swap them since they are a tiny bit bigger and they dont have the same fuel pressure problems. since i can get both of those together for less than just a new pressure regulator, i figured why not.
i am really not sure what else it could be. sorry for the long post, but i tried to be as thorough as possible.
again, any help/advice would be greatly appreciated. thanks