, I have an 80" evo custom. I lost all forward power. Bike will roll in all gears. Starter free spins in neutral but will lurch forward in gear when I hit the starter. Suggestions?

How does the clutch pack look? Also you could have sheared a pin inside allowing the gears to run free but when the torque from the starter is added to the system it may tweak enough to grab.

Let me take a stab at this. Does the starter also actually crank the engine or not besides what you described?

If not check your primary ( I'd guessing the engine doesn't crank at all). Not sure if you have a belt drive or chain drive primary. Starter drives the ring gear on the clutch shell that your primary drives the engine directly from, The fact it lurches when starter is engaged in gear tells me the clutch is not totally toast as its transmitting that from the starter through the clutch into the transmission and to your back wheel.

The gears themselves as well as the clutch shell are on splined shafts, so is the drive pulley for the belt drive and the Primary drive sprocket or cog on the pinion of the crankshaft.

My guess is Belt drive primary, belt is snapped or stripped of its teeth due to age and wear.

My Harley is 40 years old, its chain primary and drive, newer ones (except for Sportsters) I think are Belt drive at both ends, as its quieter and smoother and most cases lasts longer.