Sounds to me like y'all are still setting it to lean. Leave the low speed even with the collar. Start turning the high speed in a little (VERY LITTLE) at a time. Maybe 1/8 to 1/16 at each adjustment. I know with the fuel I am running I can not get my Tornado BB down to anything below 1 3/4 turns out or it will bog down. So do like ehroof said: Low flush with collar and high 2 1/4 out then start making small adjustment in from there on the high speed. When it bogs you are too lean. Back it off a little and do not try to lean it out any more unless you change fuel.