250 BigRed carb question

[Hair Bear Bunch]

Hi, got a problem with the Br. It runs sort of ok with the odd misfire now and then, but uses a lot of gas, smokes and soots up plugs pretty quickly. I've looked at the manual and I'm guessing it's running rich but carb adjustment dosen't seem to have much effect (problem is, once it's running I have to use it, and once I've gone through all my spare plugs it's time for tea!). So, I'm looking to move the clip on the needle but: 1) Which way? and 2) Can it be done without removing the carb from the machine?
Something I've not tried before and any advice would be appreciated.
Thanks.

[Hair Bear Bunch]

Ok, answered my own question!
Yes you can and it's reasonably easy. Found the needle clip in the second from bottom slot so I've moved it to second from top slot. Still starts and runs well. Time will tell about the sooting up.