My Rev was doing the same thing last year, 1st check your carb boots they may have a rip in them, next test your compression on both holes, if it is low (110Lbs or less) this will REALLY affect the RER.
If you need carb boots i changed to Boyesen the eliminate the carb boot cracking issue, they...
Go for the extensions and don't look back! i strechted my Doo from 121 to 144using the full rail extension that takes the slider right to the rear wheels. running them 2yrs now, no bends or twists and have surely landed on the tail end LOTS! you will need to change up your gears, tweak your...
i also have a 03 rev and hearing a strange sounds, i think it is the clutch as it sounds like rubbing or grinding metal. it is the worst at 6000 rpm
what are you hearing?