I have a 550 seca, thats been stored for 20 years.I know I have a lot to do, so I bought a clymer manual.It has a lot of excellent info, but I seem to recall that the cam chain was noisy,and adjusting it didnt seem to help.The book says how to inspect and replace the chain guides and tensioner but nothing about chain replacement.Does that mean the chain never wears out?Bike has 40000km.Any comments?