new guy

I just registered and im trying to find a little help on my bike. 1981 cb750f supersport. ive done a lot of work to it as far as new complete brake system, 4 into 1 exhaust, jet kit , carb work etc. I took for great first ride ran beautifull probably not up to full par but good. Problem is after 1 1/2 hour ride i stopped and shut bike off and would not restart. I push started but stalled out. My very unhappy wife came out and i jumpstarted it right up. made it home but very week and rough running wanting to stall out. let bike sit for a day and now seems fine again but im afraid to take for long ride. Any Ideas why this would happen. Some friends say possible vaccum lock?...any help would be appreiciated..Ive had this bike since 1986 and i miss riding it...Thanks, Mike

Hi Mike, and welcome! Glad to see another DOHC 750 here (while not exactly rare, they're surprisingly uncommon).
I second the idea of vacuum lock. After a number of years, the gas tank vents can get clogged up with crud and stop fuel flow. They jam up just enough to stop the bike (or prevent a restart), but after sitting awhile they can usually be restarted.
The easiest test for this is to let it happen again and then open up your gas cap before trying to fire it up. If the bike got you out there, it'll be able to be ridden home. That's the easiest test, but not the most fun (especially if I'm wrong!).
Or just try and clean up the vent hole in the tank.

Check your charging system while you're at it.

Oh! And your plugs. I know that's more of a cold-start thing, bit it's cheap and easy and should be done anyway.

thanks for replies will try and let you you know how it goes.