I beleive thats the actual size in inches.
adding timing usually needs more fuel. If your timing is set low then adding will help some with your richness. I dont think you have any plug reading with the gas n go technique adopted by randy. Haha
I think you can go 1 turn open from cloaed on the pj. Make a pass and check the plus. Did you ever see where timing is set?
Out on airscrew leans it, no more than 3 turns and then go to smaller pilot.
remember what your builder said! Haha
taking the lid off more than likely made it run lean so a jetting change will be needed. if you have the stock filter it is held in place with the lid so you can either cut a bunch of holes in the lid or replace it with a clamp on filter. I ride a lot of muddy/dusty trails so I use a foam filter in the stock box. we need to know what domes and jetting you have now to help.
I used some radiator hose from auto parts store, cut it and clamp it.
do your silencers slide into the pipe at all? that joint shouldn't see a lot of flex to begin with I wouldn't think.