I posted about my 87 sammy carb flooding problem and didn't get much response. I didn't want to do a rebuild or even put a carb kit into it because the automatic choke was toast and, well, I figured I'd just do a Weber conversion if I continued to have trouble. SO, I poured a can of Berryman's into the gas tank and that didn't seem to help. It was an intermittent problem and 9 out of 10 times it would start but that 10th time it would flood. Once it flooded it was impossible to get it to start. If it started once, it was good for the entire day. I was sure it was a problem with the float or the pin and seat so one day when it flooded I pulled out a blunt punch and used it to give the carb body a couple raps with a hammer. I got in and turned the key and it started right up. Whatever was stuck became unstuck with a couple taps. I had to do the tap procedure again a couple days later but since then it has fired right up. Maybe a couple raps dislodged a piece of crap that was interfering with the float or the needle and seat and I won't have to do the Weber conversion. If nothing else, this info might get someone going when they are out in the middle of nowhere with a flooded carb.   

I'm commenting here as it's on-topic:

A few years ago My Sammi flooded badly, stranding me. Until then it always ran like a top, and the Stock Hitachi Carb was something I never gave much thought to. On inspection there was gas all over it. To try to diagnose I:
1. Removed the fuel return line and blew into it, to make sure it wasn't blocked [it was good]
2. Removed the fuel hose from the carb, plugged it with a screwdriver, and started the engine at full throttle so it could breathe, then let it idle a few minutes until the float ran out. The idea being to jog the float by emptying/ refilling the chamber. This didn't work and it immediately flooded/quit when I reconnected the fuel hose and restarted it. I tried tapping the carb as well, but that did not work at the time.
Had to get towed (how embarrassing!)
I got familiar with the carb via internet and bought a rebuild kit. On tear down the carb was grossly out of adjustment, and the air horn gasket was cracked ( I was pretty careful so I don't think it was me) I experimented with the old needle and seat, it ran fine, but to be safe I put the new needle and seat in from the kit.
I've had trust issues ever since and check the sight glass nearly every start, and 90% of the time it's in the center.
 
It ran like a top until today, when I essentially had Megaton's experience. A few taps and it was fine, but I headed straight home. I've restarted it a few times and checked the carb sight glass to "catch it in the act", but it's inconsistent, the fuel level being sometimes low/ high, but usually in the middle.
I've scoured the internet for precise discussion of how this happens, distinguishing a needle valve seating issue from the float body rubbing the sides of the chamber (if that's even possible), or some kind of permanent fix, but found nothing. I'm wondering with a 30+ y/o carb it's just something we have to be vigilant about/ live with.
What I Learned: 1.Have familiarity with your carburetor, maybe pack a rebuild kit. 2. Always bring your full toolkit on a trip.