I'm back with the same problem. I'll try and keep it concise. The bike ran great then the pickup died on my 06 VS650 last fall. I replaced the pickup and the stator (eletrosport). I put it back together and now I have after-fire or pop corning from the number 2. It was so bad it was unridable. I chased the wires, reversed and tested the coils, retested the pickup and stator, changed the plugs, looked for air leaks, replaced the carb boots, and have cleaned, rebuilt, and balanced the carbs at least 4 times. Now it after-fires is on idle, intermittent at cruising and highway speeds. It has died coming to a stop a couple of times but started right back up. Occasionally the rpm surges up without input. It "seemed" to pop more when the bike was upright vs on the stand, but hard to tell. Float bowls? IDK anymore.
The carbs have been re-jetted for Big Air/Induction and rode fine before any problems. Everybody wants to say dirty carb, but I've cleaned it so many times. Plus, when I bought the bike in 2014 it had sat for 2.5 years. If I got it running from that, 2.5 weeks to put a stator in should not have clogged the carb that much on top of cleaning it several times since then. I have not done a vacuum test valve re-lash. It ran fine before the repair. Why would that be a problem now. I have video but no way to upload it for people to hear. Please help. I feel the season slipping away.