So I recently bought an 85 XR600R. My 1st bike when I was 13 was a 79 XR 250 and loved it. Now I bought the best bike from a young kid who said it was running in his ad. Of course it wasn't when I went to look at it. But, the price was right after I talked him down a little. My son and I have replaced the CDI, plug, and coil pack ensuring it had a good spark. We cleaned the carb, adjusted floats (it's the duel carb set up) and discovered that the mixture screw was missing, which we replaced. My son managed to get it started a few times by relentlessly kicking it over because he's 15. Haha. It idled unpredictably and cut out mostly within a minute not to be started again until it cooled. It ran long enough once for me to ride it up and down the road a few times backfiring with almost every gear shift for about ten minutes tops. It seemed underpowered but was still able to lift the front wheel off the ground slightly during takeoff. Now I didn't tell you that I had bought a compression gage and checked it prior to all this. It was roughly 70psi which I was told by a coworker was plenty to get it started and ride on. With all the difficulty starting it I decided to check the Haynes Manuel that I have and check the actual compression spec which I should have done from the beginning. Now that I realize I'm at/under 1/2psi compression I'm doing a little research as to what to do now. I'm not a mechanic, but I've gotten my hands in there doing simple repairs and whatnot. If I have a manual I'm pretty much good to go, but a full motor rebuild is a little daunting. I have a good friend that is an auto mechanic that lives right down the street that just started getting into restoring bikes that is willing to help me out. My biggest concern is the availability of parts for this motor. I've seen some stuff here and there on the web, but I'm looking for any suggestions that can point me in the right direction. I Really LOVE this bike and would love to see it ressurected, but I'm afraid I'm going to get too deep in to my pocket to have it make sense. Any info or suggestions welcome!