Bullfrogbiker

thanks for the sugestions, Yes it has very good compression, no signs of any leaks, and we do get a good spark, the right hand side is trying to fire but not the left, and on inspection both plugs have signs of fuel, we have had the carbs done. We think we may have put the cam back 180 out of line, so will be taking the top back of to check. after all its best to check everything again as we may have missed something. We have been using the book and are using metric guages to do the gaps, but do not have the kit to do this electronically I have been using a cigarette paper in the points to set them. I know very much old school but hey you have to use what is available.

Hi there, After 20 ish yrs standing in the garden my hubby and I have just rebuilt an XS250SE for my use. We had it running mot'd and taxed and all was going well until we noticed blue smoke and decided this was due to a valve oil seal not being correctly fitted. So we took the top off and dealt with the issue. but having done this and put it back together we now cannot get it to start. We have checked all the usual things, we have a good spark at the plugs, the timing is as close as we can get it. The tappets are correct, all the wiring appears to be good. Any ideas? I have now got to the point where a sledge hammer may make me fell better but don't think it will make the bike start and will ruin my paint job.