Yeah, I should know better than the leave it on. It was dripping slowly out the overflow so I was crossing my fingers it wasn't totally flooded. My lawn tractor floods bad if you leave the fuel on. Guess I will need to tip it over (already did that cause the throttle grip just slid off the bike, apparently someone put them on with grease and sitting in the sun it had no hold anymore...) and empty it out.

That gasket doesn't look quite right, the one I need is this one.

i.ebayimg.com/images/g/kc4AAOSwEMRnK6hr/s-l1600.jpg

Any yeah, my worry is this one has already been used a few times. Just gonna cross my fingers for now and bite the bullet and order a few new ones.

Yamaha online parts lists show a part number of 156-14184-00-00 which is the same as the Suzuki gasket I posted.  But you have the bike and can see what gasket you have, we can't.

Aftermarket float bowl gaskets tend to need to be replaced every time.  I have a 1964 Yamaha with the original float bowl gasket still.  Bowl has been off many times.  If you're careful hopefully you won't need to change yours.

I had replaced it when I built it, but that one ripped when I had to take it back apart recently. I had a pack of the gaskets you suggested and went to put one on and realized they were totally different. Thankfully, I had saved the original gasket, so I put that back on and crossed my fingers. So far so good. I guess it may have a different carb for the JDM bike? It's still a Mikuni round slide carb and fits all the jets, so who knows. I'd have to get a USDM bike next to it to see.

Also, thanks for the tip about the piston at BTDC. Once I read that I realized "oh yeah, the piston is the valve in this, that makes sense". Set it there for a few hours with the carb off and plug out. Did a quick clean of the carb, slapped it back together and it's happy again. Started on the second kick.

Yamaha has been known to have parts list errors too, especially on the newer "digital" versions.  I'll see if I can find an old parts book someplace and see what it says.

Parts book shows the 164 prefix part number so the online Yamaha catalogs are WRONG on the float bowl gasket.

Great job that you figured it out and already found the right part number!