Did you poke out the jet in the bowl nut with wire several times? Sounds like the needle and seat are past it if the primer is dribbling petrol
If you want the motor, throw one of these on it
https://www.ebay.com.au/itm/354356775601?It was shockingly dirty inside. The jet looked clear when I peeked.
Thanks loads for the info and link. I was going to look into a new carb until NormK mentioned his dislike of the primer system. Unfortunately it's difficult to convert to choke as the primer is part of the filter housing.
