This is my first post, I'm helping a friend with a problem with his heritage 80 inch.

He was driving the other day, and then it started missing, and eventually he managed to nurse it home. Then it would not start. It would crank, however. Checked the plugs, and see NO spark.

So then he puts it on a jump from the car, and it starts right up. It continues to start and run fine, but when he drives it a couple blocks, the missing starts again, and then it won't start up again. BUT there's enough juice to crank the engine.

Is it possible for a battery to have enough juice to crank the engine, but not fire the ignition?

 

Is it possible for a battery to have enough juice to crank the engine, but not fire the ignition?

No you have other problems. Never jump start your bike from a car. Too many amps. You risk damaging the bike's components. Load test the bike's battery for starters so you know what you've got. Test the coil. First test it cold. Then heat it up with a hair dryer & test again. The ohm values shouldn't change between cold & hot. If it passes ohm testing then tap test it with a condensor. If it fails either method replace it. Ohm tests alone can miss a fault that a tap test will reveal. Not familiar with your set up so these are general tests one would complete with your complaint. Don't know the specs on your equipment, you'll have to look that info up yourself.