there are no aftermarket sprockets for the doodlebug. you'll need to get a blank and have it machined to work. chances are if you try and drill your own holes they won't be perfectly centered.
if you go with a straight pipe it won't gain much (if any) power but will be loud. i've found my 5.5 clone actually runs better with the muffler on it (replacement style one from Ace). it's more fun riding around with just the straight pipe though.
if you go with a straight pipe it won't gain much (if any) power but will be loud. i've found my 5.5 clone actually runs better with the muffler on it (replacement style one from Ace). it's more fun riding around with just the straight pipe though.