Cutting the baffles out of the exhaust pipes on your motorcycle is one of the most common and least expensive modifications that you can make, especially in lieu of purchasing aftermarket pipes. Done to increase the sound of the motorcycle while riding, it is important to note that without proper modifications to the air intake and carburettor, no power gains will be made by simply drilling out and removing the motorcycle's baffles.
Unbolt the stock exhaust muffler from the exhaust tube. The bolt to remove the slip on muffler is located just under the passenger foot peg, and can be removed with the socket wrench. When the bolt is loose, locate the second mounting bolt located between the mufflers which secures the exhaust system to the frame of the motorcycle and remove it, as well. Pull the mufflers off of the exhaust pipe toward the back of the bike.
Secure the mufflers to a sturdy work surface and look inside. The actual exhaust pipe is surrounded by a flat metal plate which looks like a washer. This is the part which will be removed.
Insert the metal grinding bit into the drill and grind away the weld on the outside of the flat metal plate. Be careful to avoid heating the metal too much, as overheated metal could discolour the chrome muffler housing.
Place the hole saw bit into the electric drill and cut the flat metal plate from the exhaust tube. This is done by centring the hole saw in the exhaust pipe. The hole saw's guide pin should be in the centre of the pipe.
Remove the loosened metal plate from the exhaust pipe. Behind it, you will find metal or fibreglass packing material. Pull out the packing material, then put the extended length drill bit into the drill. There is another baffle further back along the exhaust pipe, but you don't want to remove it entirely. Use the drill to cut holes into the secondary baffle surrounding the centre exhaust pipe.
Reinstall the slip on muffler onto the exhaust pipe, utilising the same mounting locations. Tighten the bolts securely before starting the motorcycle.
Avoid removing the baffles of a motorcycle in a town or city in which noise ordinances are enforced, or if you ride primarily at night through residential areas.