Since my bike got jacked, Ive taken over the wife's CM400A. Its got a few problems... First, its slow. Being an auto with 2 speeds, thats expected. Especially a small one. Second, its a gas hog. (refer to the first issue) and lastly.. its loud! Its whiny loud. the exhaust has a droning whistle to it. Very, very annoying. Any suggestions on period correct exhaust, or something I could do to pop the codes open and baffle them (got access to a full shop)?