I bought my first bike in July off my father. He is the original owner of my 2001 Heritage Softail Classic. The bike is stock other than the Thunderheader he put on it. It is fuel injected and he didn't do any download or stage 1 and the bike has approx. 36,000 miles that way. My question is am I damaging the motor this way? The bike runs good, but it does backfire and pop.