I picked this up at the junkyard for 50$. It's complete (some of the parts I've removed to get at the carb). I have no idea what it is... The seat says DR, but the engine has a displacement of 160cc.... The tag says 12/79... So I'm assuming it was built in December of 1979.. The only other code on the tag is 01426. I got it running without too much difficulty, but it ran awful! No idle, backfiring while I revved it (throwing flames out the exhaust)... Ran a little better with choke, so I pulled the carb and it is soaking as we speak. Am I on the right track? What else should I fix/clean while I'm in here? This is my first dirt bike so I'm pretty excited to get it working and hit the trails! The exhaust was completely shot... I'm thinking of installing this carbon fiber I have lying around??