[muffinman]

http://katriders.com/wiki/index.php5?title=Carbs_102

[arsenic]

(And I'm not following how a carb gasoline overflow spills gas into a sealed oil reservoir since the carb feeds into the combustion chamber above the piston rings)

The fuel seeps past the rings, it doesn't just sit there.

[KatanaGSX92]

Could also explain why it cranks and then "siezes." If you've got gas in the cylinders, it can't compress it and stops the engine from turning. After a while, when the gas seeps past the rings and you try and start it again, the remaining gas vapors in the cylinders ignite and the bike will run until the next time it sits for a long time.

[ManQu]

Fuel leaks into the cylinder bore ,then leaks past the piston rings and into the oil below, the leaking past the piston rings is called "washing" .This is where it cleans the oil from the rings and bore causing untold wear and possable damage as you start running the engine.Untill the oil is replaced and lubrication continues.

Hydraulicing or hydralock is where enough fuel has leaked into the bore to stop the piston from compressing the fuel mixture and locks the piston from going passed top dead center.this can cause many problems like bent conrods ,valves even snapped timing chains.I've seen many cars with holes in the block from a conrod break and slam through the block wall...all from a severe over fueling... hope this helps explain some towards the reasons for checking the carbs and petcock is so important!

[lowmaintenance]

So I'm going to begin the endeavor tomorrow. I expect it'll take a few days, as I figure out the simplest things like how to remove the fuel tank, and as I assess which gaskets and parts need replacing.