If you were gonna try cleaning the reeds, i would use gasoline i suppose. thats what theyre made for, and straight gas is sometimes used as a solvent. As far as the the carbon in the pipes... ive heard that tossing a handful of screws and bolts into the pipe, with some gasoline(NOT premix) and shaking the headers around for a few minutes will loosen and remove some carbon build up. As far as removing the carbon on the exhaust port, which is what i think your asking. Just put some carb cleaner, or another type of contact cleaner, on a rag and wipe it off until its clean.... Just make sure all the nuts and bolts that are supposed to be tight, are tight. All fluids topped off.... If your gonna do a topend rebuild, just make sure you clean the base of the cylyinder(where they meet the lower half) very well, as to not knock dirt into your tranny and whatnot. Also, where the head meets the jugs. If your having the jugs bored and honed for a true FRESH topend, make sure you clean out your jugs before you put them back on your bike. Once its together TORQUE your base and head studs accordingly in the right order, and to the right specs(torque to 10lbs, then go back and retorque to 15lbs, and then again to 20lbs) .............make sure you retorque everything you put back together, after a few heat cycles, and again after a ride. Dont doubt yourself, its an easy process.