If an 500 cc single cylinder is suddenly easy to handle, then something is wrong. To look for the cause of that ease of use, you do not have toto be a plagiarist professor. “Recognizing burnt valves” is one of the first chapters in Old Motorcycling ”. And special tools such as valve pliers? Nowadays you can also buy that for small change from our advertisers.
After dismantling the valve everything became clear: Apparently the veteran had driven the wrong valve clearance. The resulting heat had not left the - apparently ever mounted valve seat ring and the valve cold. Rarely seen such beautiful leak marks! A new valve cost 20 euros ...