I'd still put a little gas in the carb and see if that makes it fire. I have had a couple clogged fuel filters and when that happens it suddenly goes from workked fine to not at all. This sounds like that, out of gas.

Eric
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'57 Chevy 3100 (Little Red)
'81 RD350 LC - Fun, Fun, Fun
'83 GS1100E - Pocket Rocket