CEG Posted June 20, 2006 Share Posted June 20, 2006 Hello Can anyone offer a likely cause for a problem with my 1984 XS400 dohc. It starts on just the left cylinder until it's warm(ish) when the other cylinder cuts in. Only clues are that I can't check the plug as it's stuck (don't want to force it until I know where to go next) but connecting a spare plug shows it is sparking. It runs and starts perfectly when warm. Any suggestions much appreciated. Thanks CEG. Link to comment Share on other sites More sharing options...
Moderator drewpy Posted June 20, 2006 Moderator Share Posted June 20, 2006 Hello Can anyone offer a likely cause for a problem with my 1984 XS400 dohc. It starts on just the left cylinder until it's warm(ish) when the other cylinder cuts in. Only clues are that I can't check the plug as it's stuck (don't want to force it until I know where to go next) but connecting a spare plug shows it is sparking. It runs and starts perfectly when warm. Any suggestions much appreciated. Thanks CEG. difficult one..... maybe a valve seal leaking causing oil to run into the cylinder. after a bit the oil is passed through the exhaust and the petrol can ignite. When warm the oil hasn't got time to drain past the seal. do you need to top up the oil level much? Are the valve gaps correct? you need to do a compression and spark plug check, get yourself a helicoil insert first before you take the plug out. Then your covered Link to comment Share on other sites More sharing options...
CEG Posted June 20, 2006 Author Share Posted June 20, 2006 difficult one..... maybe a valve seal leaking causing oil to run into the cylinder. after a bit the oil is passed through the exhaust and the petrol can ignite. When warm the oil hasn't got time to drain past the seal. do you need to top up the oil level much? Are the valve gaps correct? you need to do a compression and spark plug check, get yourself a helicoil insert first before you take the plug out. Then your covered Thanks a lot. It doesn't appear to be using oil (I only use the bike occasionally) but you've given me some ideas to look at. Cheers. Colin. Link to comment Share on other sites More sharing options...
Recommended Posts