Just a very quick update here regarding the devil's urine called ethanol. I took the overflowing carbs off my 1988 Kawasaki GPX750R to see what I could see - the inlet rubber for number 1 was wet giving a pretty clear indication that carb number one was the one with poor bladder control. When I took the bowl off it was immediately apparent what had happened - in part it was down to an act of bodgery, in part it was down to the evil ethanol in E10 fuel.
Firstly, let's be clear there is no need to use any sort of sealant when rebuilding carbs - they should seal fine without it, manufacturers don't use it so neither should you. Secondly if a gasket is damaged just replace it, any sort of bodgery will end in tears before bed time. Such was the case with my locked up Kwaka - somebody had used sealant on a broken gasket o ring, the sealant had been attacked by the ethanol, it had gummed up the needle valve and was not even doing a job of sealing any more.
I now have the service kits on order, I'm pretty certain that once done the bike will have no more carb related issues. They will all be fully cleaned and rebalanced to ensure optimum performance. All I have to do then is sort out the badly bodged airbox, which is currently leaking air at a furious performance sapping rate.