[Chasletini]

Hi chaps. I just joined. I have a 1983 Yamaha XJ 650 Custom, a very pretty bike. I have run it for a couple of years (one full service in that time) after buying it on Ebay. Three weeks ago I couldn't start it - don't know why. A guy said take off the plugs and burn them off and try again so I did. Still wouldn't start. Then suddenly it burst into life and reved very high (I wasn't holding the throttle, the other guy was and he had it on full twist). Then it died very suddenly. I left the bik for a day and then the next day started it 100% fine. But it died after abou 2 miles of ride, as if the gas had run out. The day after I tried it again and the same thing happened. I tried it a few more times (give it 24 rest, then it sttarts fine, then it dies). So I took off the carbs and they look clean and good and re-seated them; I took out the air filter and it was very oily (could this have been the effect of the very high revving occassion?) so currently the bike doesn't have an air filter until I get a replacement. I have run it with the petcock on Prime to see what would happpen. But each and every time I get the same behaviour: after a 24 hour rest it starts and runs fine for a mile or so and then dies as if it is running out of gas. Is there any kind soul out there who can suggest a solution? Cheers, from England!