I own an AMF era super glide. A '77 FXE to be precise. Purchased it new. Problems? Just the normal leaks they all had. It's got 80,000+ miles on it, And is still actively ridden. It gets a top end every 20,000 and a bottom every 40,000. It got those in November of last year. Top ends are easy and I can now do one in about a day. The bottom end takes a little longer. About the only other thing I've done is replace the clutch basket and clutches. The trans is OEM. It's had wheel bearing, primary and drive chain and such. Again, all normal wear items. The only thing not stock is the brakes and the oil filter system. The in-tank stuff was not the best and was replaced with a high performance oil filter setup and oil cooler. The pie caliper and rear were replaced by PM billet units. But I still have all the OEM parts.
My brother owns a '76 Liberty Edition FXE. About the same mileage. He is the second owner and purchased it with 2000 miles on it. He has done brake and oil filter/cooler mods also, and has his OEM parts.
Both bikes still run the points ignition system.
Both bikes were ridden cross county, New Hampshire to California and back in the early 80s. And made trips up and down the East Coast many times since. They are still capable of making those trip again, multiple times. Maintenance and oil changes is the key to keeping AMF era equipment running. It's also part of riding. You take care of a shovelhead and it will last forever.