Hi I've been lurking around the site for a few weeks so decided to join. I've just started riding dirt bikes. Which at 29 is a new thing for me , I got a 1983 rm 125 which I bought cheap . I rode it 5 minutes and then it died, I didn't know anything about dirt bikes so I bought the manual, bought a new piston , got the cylinder borred out and after much trial and error reassembled the bike and it started first try!