pics for greybeard's prose:
Draining the bowls. 3mm allen wrench. some tubing and a hose
The hidden filter. your husband will need to use your smaller hand...This pic is with the carbs on my bench.
SeaFoam will clean the jets and help wipe away the gas residue (varnish) but the SeaFoam has to flow through to clean. Thus draining the bowls will do this in an extremely minor way. What draining the bowls will do is tell you if you are getting gas to the bowls. Turn the petcock off. Drain a bowl. With the bowl drain still opened turn the petcock back on to observe (or not) fuel flow, then turn the petcock back off and repeat for the other bowl. Smell the gas that drained. A burnished colour or a funky smell will tell you the gas has gone south. If you have bad gas, drain it all out. Having added the seafoam already, drain the gas using either or both bowl drains. Passing gas so to say. You can drain from the petcock too. Regarding the thought that the float needle(s) might be gummed up into their seat(s) a gentle tapping on the area of the bowls might free them up. However, when you turned the petcock on with the drain open, and fuel flowed, that needle is not stuck in the seat. Should gas not flow, Gentle now, use a rubber mallet as these are soft metal and will break if you hammer it hard. I am writing backwards, should gas not flow from either carb bowl with the petcock turned on, Disconnect the fuel line from the petcock and drain some gas from the petcock. Good. Now the next place that might be clogged would be that itty bitty filter, see above pic. Don't get sceered. chances are just draining the gas and charging the battery will get him rolling again.
You will have to charge the battery. The clicking you heard is telling me that.
When you get this sorted out, run at least two tank fulls of fuel mixed with seafoam through (by running the motosickle). Not on the sidestand but by stretching the throttle cables.
Then always use a double dose of stabil whenever he will be away for a while.
God bless you and your husband for your service! Merry Christmas!
P.S.: Here are some
pictures of removing the carbs. From disconnecting the fuel line at the petcock to well having them on the bench. Disregard the photos of the removing the manifolds.
Here is some betterer detailed destructions per our fearless yankee brewmaster, lord iamanasshole
dinqua 
