flicking over an engine by hand alone wont prime it, putting your started on it forces it to suck, but at a slow rate. the trick is to open your carb fully, plug it with you thumb and flick it over 3-5 times, then close it again, attach your clip and flick it over.
i recently got a small 2oz tank and the tube was too still to leach the bottm when the tank was level , i just used some tubing with a thinner wall. i also use the soild joiner method to stop kinked klunk lines