You must not have looked at manuals that I posted. Page 10 in operators manual: intake valve .003-.005, exhaust valve .005-.007, spark plug gap .030, adjust valves with engine cold. Check oil level on dipstick, if it is high & smells like gas carburetor problem. Fresh gas, air & fuel filters & spark tester to check for spark at plug. The answer to your camshaft replacement is no. How are you adjusting valves, procedure?