I'm not much of a mechanic so maybe a dumb question. Anyway I'm thinking about buying a 2007 vstar 1300 tourer and it says they have an overhead cam. I've read on the forum that you have to periodically adjust the valves. I thought with an overhead cam that the valve stems were in direct contact with the camshaft there by eliminating any solid or hydraulic lifters. So what I'm asking is why would have to adjust the valves then. Thanks in advance for any help.