Popping on deceleration, running lean. What screws do what?

[JohnGS850L]

I turned the fuel mixture screw in half a turn. No change in popping on deceleration, but there was noticeable change in popping while choked warming up. It has done that a bit before, but this time around it was popping every few seconds almost immediately on startup.

[Tom R]

Did you replace the fuel line when you replaced the petcock? Make sure it's properly routed and doesn't have any kinks.

[OldVet66]

Have you changed the boot O-rings and checked the boots for air leaks? The air box can also cause issues. It's a major problem with these bikes and could definitely make it run lean.

[JohnGS850L]

Did you replace the fuel line when you replaced the petcock? Make sure it's properly routed and doesn't have any kinks.

New fuel line with the new petcock. No kinks.

[JohnGS850L]

Have you changed the boot O-rings and checked the boots for air leaks? The air box can also cause issues. It's a major problem with these bikes and could definitely make it run lean.

Air box has been resealed (very thoroughly by me), and the PO had changed the boots and O-rings within the last year. They look to be in excellent condition, and using the carb spray method, there is no indication of air leaks.

[Gorminrider]

Might be carbs, but re: pictures of muffler-

IF the guts are rotted out, there's no point patching them on the outside- it'd be like running straight pipes without any baffling and will explain your popping.Is the rest of the exhaust system so bad? and how about the crossover pipes underneath?