It's 1998 GL1500 SE 50th Anniversary Edition with 30,700 miles on it that was recently given to me by my father. It ran like a top the day he parked it, but had been sitting in his garage for a little over 2 years without being started before we trailered it to my garage and, you guessed it, it will not fire up

I've siphoned the old gas out (was pretty stinky), filled with fresh 87 octane and 1/3 can of seafoam, and installed a new agm battery. Crossed my fingers it would fire up, but the starter just cranks and it doesn't even sound like it's trying to run. It will, however, run ever so briefly until it burns through a couple squirts of starter fluid sprayed down the carbs, then dies, so I assume it's a fuel delivery or carb issue. At this point I'm not sure what to do or even check next. I've watched a couple videos I found on these forums on how to remove the carb, but I'm really hoping there's some other things to check or clean or replace before that nuclear option is necessary!!
Thanks in advance for your replies.