Motorcycle Repair: 1982 V45 Magna, vent hose, stale gas

Question
I am currently working on a 1982 V45 Magna.It will run good for about 4-6 miles or until warmed up, then it will start to die when gas is at idle to mid range, but will run a little while longer if gas is held wide open.It will then eventually die and not start back up until it cools down.Any ideas will greatly be appreciated.

Answer
Kyle,

here are some things to check:
Gas tank vents plugged in cap or tank preventing fuel flow.
Carb overflow/vent hose misrouted/pinched.
Fuel filter plugged or no fuel.
Collapsing gas line(s). Rubber slivers in line.
Rust in gas tank plugging fuel system.
Plugged or faulty fuel petcock or vacuum valve.
Stale gas or water in the gas.
The fuel pump minimum flow capacity for one minute is 800cc
Failing pulser or ignitor units. Check for spark.
Failing ignition coil. Try switching coils.
Failing ECU or spark control unit.

When it quits try to check for spark.
and if possible spray something like wd-40 in the
intake to see if it will run. Maybe you can
narrow it down to either gas or electrical problem that
way.