I recently bought a '90 Yamaha XV535. I cleaned the carbs and was able to start it. I then decided to pull the tank and flush it out, replace the fuel filter etc. While the tank was out I took the opportunity to weld a little tab that holds one of the side covers back on with a little flux core welder. At the time of welding the battery was out and all the connectors around the fuel tank were disconnected. Now I’ve put it back together with a new battery and everything works - except spark!

I’m here kicking myself really hard for being so stupid - welding with the ignition module still connected. But then I did some reading and most stuff suggests that just disconnecting the battery is enough.

I’m going over it again today cleaning and reconnecting all the connectors but I’d welcome any input. Have I fried my ignition or is there a chance it’s just a dirty connection?