G80 Monobloc issues (again).

[crawsue]

I'm still in search of the perfect 'carb set- up on my '59 G80s.It is running well and I have not a bad tick-over,the plug is a nice brown colour.But starting from cold and hot is still a bit hit or miss,I 'm still not completely sure where the adv/ret lever should be.I let it idle yesterday while I did some other stuff,and after about 3/4 minutes it started to slow down and then just "chucked it".Is this possibly something to do with an engine heat to carburetor issue or possibly the petrol in the float chamber "frothing up" with the vibration? My G5 would happily sit and tick-over all day,with a similar carb'.Any thoughts greatly appreciated,or am I being pedantic? !!