RE: Gas engine forum
RJ , When you are flipping it with the choke on, do you have the throttle open (off idle to half throttle) or closed (idle)?
If you have the throttle open it helps to draw more fuel into the crankcase .
If you are already doing this and still having problems 2 things come to mind .
1) you may have some reeds not closing completely and the backpressure blowing the fuel back out of the carb instead of drawing it in . (slight non sealing condition may not effect actual running)
2) you may have a minor vacuum leak leaning it out (least likely since you haven't described any other problems)
I would recommend trying some carb adjusting and maybe changing your start procedure first , then look into the 2 items above.
I had this concern on an older 3w70b2 and it ended up being the reeds and the rubber seal for the reed cage not sealing well.
I replaced the reeds and the seal and resolved the problem