hi daniel there are restrictions in the exhaust usually a metal sleeve insert inside the header pipe (not on every ped) where it bolts onto the engine. also there's a pipe called a kidney pipe sticking out halfway down the header pipe before it meets the silencer box, it looks like a large thumb. this is cut off & sealed with a weld & is what you have been told to grind off. your probably keen to work on your own bike but i would be wary of anyone that may be unsure what they're doing to start grinding stuff off their bike, once its chopped, its chopped for good. there are other restrictions on your & a bike shop should only charge a couples of hours labour to derestrict your ped. hope this helps........happy motoring.
steo, June 2009
