Exhaust Insides of exhaust are gone how do I replace?

[HeadSmess]

I like my motorized bicycle because I can take it places I can't take a motorcycle. Have you ever tried to lift a harley over a fence?

or even a pitbike, for that matter? one particular track around here... its called winchbreak hill for a reason. no WAY would i ever take a full size dirt bike down it. unless i was one of those trials riders that could climb a near vertical wall of rock and boulders...