So I cheated and did not pull the bike apart, and after watching lots of vids I did the Napa thread saver dry, as in no grease. Between the vacuum and air blasting with the compressor and a thin rubber tube there was no sign of any shavings.
I also took the carbs apart and did another cleaning, paying particular attention to the pilot jet circuit. I got good spray out of the little holes above the throttle valve.
It was slow to start and would not stay running so I replaced the right spark plug with a fresh one. Today it started up ok, but I had a really bad hanging throttle. I sprayed carb cleaner everywhere but no change in revs. Then I started turning the throttle and pushing on the balance adjuster between the carbs and it was fine. Turned out I buggered the spring on the balance adjuster so one side was hanging up. Once that was fixed I let it warm up, tried to adjust the pilot screws but there was little difference, just more backfiring. After a carb sync it settled down but I still get popping from the exhaust with a blip of throttle. Also the stumble is better, but still there. A quick ride down the street and the bike seemed to respond well to throttle, and no popping.
Reading through the pages here I read that the popping is a lean condition and a fix is to increase jet size. Does that sound right? The bike came with a 2into1 exhaust but I have no idea what kind it is. The main jet is a 70, so does it make sense to by a 72 or 75?
I also noticed my exhaust header bolts were starting to slip, so I tightened them down but it was too late to run it again.
Hoping there will be more nice days ahead so I can try to enjoy the bike before the snow flies.
Thank you.
