1982 atc 185 runs then stalls

[Goose it]

I got this atc 185 and I've gone through is now and adjusted the valves, cam chain tensioner, cdi timing, and I've pulled the carb and cleaned it twice now. This thing still wont stay running for me. It fires up but when it gets warmed up so about 5 min of running it stalls out. It's still getting gas and spark but it wont fire up till its cooled off. I'm wondering if it as something to do with the cdi advanced timing or maybe a spark plug. Any suggestions would be appreciated thanks

[Tri-Z 250]

This may seem dumb but does the gas cap have an off/on ? It’s a breather vent off is for transit/storage. It can vapor lock the fuel causes fuel to stop flowing...in time it slowly releases pressure then builds back up after a short ride.

[Goose it]

Ya it does and I checked it. I did however pull the cdi cover and found the bolt broken and the advanced timing arms (at least that what i call them) are missing the tabs that sit in the shaft...so now I need parts lol