Hi, glad to join this forum, hope to see some good info on these bikes. I have a 1980 Suzuki GN400X. It runs good, starts on the second kick. It has a bit of a miss at about 2,000-3,000 RPM. When it shuts off, it backfires out the exhaust. I´m wondering if anyone else has experienced this. I think that the timing is off. Anyone have any experience setting the timing on these bikes. I know that I need to get to the ignition in the engine and have the cam cover off. Just don´t know what two marks to line up. Any comments?