Chainsaw Repair

it has a lot to do with the idle. if the low is set too rich, you won't get it to idle low enough without it loading up and stalling. if it's too lean, you won't be able to open the throttle up enough to keep a steady speed and the idle will fall off as it runs out of enough liquid fuel. if you can't get it to idle low enough without it either dying or the chain moving, you might have an airleak playing games with you.
there's nothing here on these saws that is rocket science. if the crank isn't chewed up from a bad drum bearing, and there isn't any 'glaze' on the crank where the bearing contacts (you did use a scotchbrite pad on the crank where the bearing runs didn't you? and you oiled it right?) and the bearing is new, and there isn't any binding between the clutch and drum or crank. the chain should stay put if the idle is in the right area.
that being said: on these little saws, the idle has to be up pretty high for the chain to start moving. I've had them idle as high as 3400-3500 and the chain is just barely starting to twitch.

I have no idea why my post did this

I had those that twich regardless as the springs had run hot and lost tension. With the ones with conventional spring and three shoes you generally have a lot higher rpm before it engages.