@appleman061: Put a fmf on #yamaha #pw80 #fmfexhaust #dirtbike

Bryan Medeiros :

The FMF pipe on those looks nice, but doesn’t really add that much performance. It’s cheaper just to modify the original pipe by cutting out the baffle piece in the head pipe, and cutting out the rear silencer connector tube, and replacing it with a larger one, opening it up to allow more exhaust flow . Or even better fabricate your own expansion chamber out of sheet metal if you have fabrication experience using a computer program where you input port timing. These things will surprisingly haul ass especially if you shave a millimeter or two off the head and port the cylinder. Do some porting on the intake manifold too and an oversized carburetor. I believe another modification is using a KX 60 CDI box. These things sound like a mini YZ80 when you open them up. 😆