No Spark now but started earlier today.

Ok. I just bought a 1978 kz 650. the bike was able to start but only briefly before it sputtered out. I took apart the carbs and cleaned them but they were pretty clean already and when i put them back in the the bike it didnt start. I thought maybe it was my mistake but i then checked for a spark and nothing. i tried jumping the bike as well and the starter engages just fine but no luck. Any suggestions on what could be the problem????

I hope you did not try to jump it from another vehicle that was running at the time. That can damage things and should not be done. Ed

i had charged it after disconnecting the battery. I fear for electrical problems and surges like that.

If there was a connection when i was chraging it though, what would usually go bad. im stuck right now and cant find anything. it does have an after market dyna contact and condenser and coils by the way.