Starts up but dies down the road.

I'm new to the motorcycle world and got a 80 kawasaki kz440a for my starter bike. It running rich. When you take it down the road it go but out no where it just kill over and sometimes it will start up again sometime it won't. Any ideas?

Take a look at the gas tank air vent.

Sounds like coils.
Steve

I ordered a new gas tank cap and I used my voltmeter ando got 2.7 but when I went from positive to spark plug in got nothing maybe the secondary out. But it is giving spark next to the engine.