How long does a Harley engine last?

Evo engines and the primary drive seals will start to give you trouble at 30,000 miles and by 40,000 miles you will need to rebuild the top end, bore the cylinders and install new pistons and rings and gaskets. As long as you have your tools out, you might as well replace all the primary case seals because if they are not leaking now, they will be soon. Anyone who tells you different doesn't know squat about harley's. Also all harley dealership salespeople will tell you otherwise because they are trying to sell you someone else's piece of crap headache that they just traded in