Ya, what Brian said. If I remember correctly, watch the position of the left side clamp bolt when refitting the (new) muffler so it doesn't interfere when the side stand is in the "up" position. I can't remember why I know that

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Also like GB said the rear bracket bolt/nut assembly sometimes spins with the nut on the inside. A quick spot of heat from a propane torch can, may loosen the nut-tight stuff in there. I can't remember how I know that either

Good Luck
jh