78 Harley with points runs for 5 miles and shuts down

SOURCE: my y amaha v star 2001 shuts down when it's running

Ga_drifter has a good suggestion here. If that does not work for you, check for crimps/kinks in the fuel line itself. More than likely behind clamps/ties where not visibly seen.

SOURCE: 1986 Yamaha Radian stops running after 20 minutes

Sounds to me like it could be a few things... pretty interesting that it runs and shuts down...sits for a little while then fires back up. Could be something as simple as a bad ground.. maybe it needs cleaned.. if the ground is making very little contact.. the bike would run bad, and because its direct current it has to flow. The metal in the motor frame etc will hold so much DC current.. but *** soon as it load up the bike would stop sparking. Let it sit for a while, DC trickles into the battery through the slight contact, bike fires back up. OR could be bad venting of your fuel tank, or a partial clog at the pet ****.. the first is pretty easy to check, open your fuel cap and start the bike..if it does the same thing then its not a vent problem. One thing that does happen on the Radian, is the reserve fuel screen inside the tank comes loose, and then everything inside the that has built up over the years either partially clogs the pet ****, or the hose, or both. Take the tank off, pull the pet **** off..if it still has two intact tubes with good screens..you probably don't have any junk in your line..but I would pull the line off and blow through it any way... it could be some type of blockage, when the bike sets the fuel seep through, but when it runs it eventually creates a vaccuum that stops the fuel flow. Those are my two first thoughts... good luck!!

SOURCE: 2002 Zuma starts, runs for 1 to 2 minutes then shuts off.

There is a very good chance your fuel tank vent is plugged. This causes basically a vapor lock thus no fuel is able to reach the carburetor or fuel system. By letting the bike sit you are essentially letting fuel get through the system enough to let it run for a few minutes. So check for pinched vent tubes, this happens frequently after you have a routine service performed and the tank is removed.
Good luck and let me know if this helps you.

SOURCE: yammy rd 200 1978 inconsistent running

check the neddle valve seats under the float bowls,may find that theseats are not sealing,to test,take the carbs off the bike,remove the bowls ,compress the floats untill they are all the way up(simulates full bowl of fuel)then blow through the fuel inlet pipe,you should not be able to hear air passing throgh the valve if you can replace the valve seat and the needle valve,sorry cant remember point settings,long time ago since i worked on one of these

SOURCE: HARLEY DAVIDSON 125TX WILL NOT START

replace plugs also on carb there will be a mixture screw the person probably adjusted this you need to turn this out and see if it improves 1/2 a turn if not screw it in 1 turn if still no difference fiddle with it also replace/clean air filter this may help good luck bud