So… rebuilt the carbs: cleaned all the ports, made sure there were no obstructions with plenty of cleaner, cleaning rods, and bottle brushes, made sure float high was within spec, and that both bows were full of fuel. Started the bike and after it warmed up I shut pushed the choke in and it idles just fine. With any twist of the throttle the front cylinder goes dead (verified with thermal gun). Pulled the carbs off again and checked the jets and no visible issues. I’m not too keen on what to check next. Any help would be appreciated.

 

Found out why it would die.

 

Glad you found it. I was about to say inspect the diaphragms for tears.

 

I was hoping that I wasn’t going to have to pull them, but I’m glad I did. I always worry about tearing them or pinching them upon reassembly. It’s a pain getting them to seat right when putting the cap on. I did figure out that if I used a small piece of 3/4” pvc and used it to rest the slide on it helps get the diaphragm into the perimeter of the carb body.

 

the stock springs boing like 2ft long...what a PITA.
makes it worthwhile to get the jet kit just for this reason...but I'll try the pcv next time i pull mine

 

i ran a DynoJet kit with the shorter springs and followed the set up and even got it DynoJet tuned but it was awful. I suggest the carb set up “Sticky” in this forum thread. That’s how I have my carbs set up and I’m happy with them for now. Just need to get air fuel ratio gauge to fine tune them.