Fuel delivery: Blocked filter (take it out of system to get home), bad fuel pump, clogged line or carb, needle valve stuck/bad, float stuck See if you can keep it running with choking the heck out of it.
Electrical: check spark, if possible, at a plug. Check for loose wires to coil and Dizzy. Check wires to Ballast resistor. Check wires at Ignition switch. Look at points gap if possible.
If it only runs 19 miles at a time, you should get home!
May be hard to fix on the road. Been there.
