What Eugene said
Complete tuneup. Make sure the gap is correct. Same with points. Make sure they aren't burned or glazed. If glazed pull a matchbook cover through them or some brown grocers paper. Make sure the contacts in the cap are clean. Make sure ALL connections from the battery right up through are clean and bright - and the grounds as well. Ensure the saddle switch is clean inside with no corrosion. Same with the contact on the starter. Verify all.
Then I would run some SeaFoam through. 1/2 can in the crankcase and a 1/2 can in a tank of gas. You may also want to check the valves and adjust the lash. Not hard to do. If I can do it anyone can.
Then check you fuel circuit - from the tank, through the fuel sediment bowl, to the carb inlet, metering jet and of course the needle and cage. Clean the metering jet - both orifices - use a strand of twisted pair aka telephone wire. Nothing stiffer otherwise you may end up deforming/scratching the jet. Ensure that the longitudinal orifice at the end of the jet is not plugged.