Thanks Derek. Its so easy to get confused over the terminology. In the Mikuni case I think I’m right in saying it is a fuel metering screw. So when it is screwed right in it should shut the fuel off which is now the case but it keeps running so is getting fuel by another route right. The carb came with spare, different sized spare jets. Time to try one. Bigger or smaller. Will be a pure guess on my part. My old brain can’t handle the logic approach.
I vill be back !