I carefully count the settings for the HS and LS needles then remove them. Give a flush and pass a pipe cleaner soaked in lighter fluid or charcoal starter through and give a little scrub. Replace needles and count out the old setting.

Can be amazing the goop you see on the cleaner if the motor has been sitting around, especially if it was run with castor.

For HS needle setting, open throttle all the way and connect a length of tubing to the fuel nipple. Screw needle all the way in. Blow gently into tubing, opening needle slowly. Quit when you first start to get free air flow. You are at or close to optimum setting.

For LS needle, open throttle about 1/3 Close needle then advance and blow like before. Quit when you first start to get a whiff of air flow.

And be sure to inspect your fuel lines and tank for needle holes in tubing, stiffened fuel line with non clunking clunk, etc.

Tom