I don't have the CR IIs, but sounds like my carbs did when I changed to the TBS needles. I put a shim on the needles first and it bogged bad at rollon and sputtered when at a constant speed. I could slow rollon, but it really wasn't much better. I took the shims out and it ran perfect, which told me it was getting way too much fuel from less exposed needle. If your screws are only one turn out you probably need to drop a jet size or two to give you some adjustability. Jets are cheap, I'd buy a couple different sizes lower and try them all, then stick with what works best.
