tune up

I don't think you're giving those plugs a fair Shake. They were a year old and had went through quite a bit. they were on when I had the old Cam and breaking in the new one. I just got the carburetors kind of tuned in and never change the plugs or clean them. And then even worse I started it all cold with the choke on and shut it off within 30 seconds and pulled the plug out, but I thought I had said all that along with the picture...
Maybe you could ask YR to help tune the carbs.
but ya gotta ask nicely. lol