Asking if the decompression lever is clocked improperly will that affect valve adjustment?

 

Not sure what you mean by "clocked" Fairly sure the decompressor is a simple cam, working on the top of the rocker arm, with lever one way the cam is on a flat which doesn't touch the rocker, with lever t'other way, cam pushes rocker and valve down, letting compression out through exhaust valve. If you tried to set valves with decompressor on, you would have a very wide valve to rocker gap when you move lever to off.