CM2250 Engine vibration,noise

[Jerzy609]

When I'm at idle it will fluctuate 10rpm sometimes.I can also hear a sort of a ticking but not really loud on the top towards the front of the engine.When I'm going down the road that's when you can definitely feel and hear fast vibration.On a second and off a second even when I'm off the throttle coasting it feels like it a longer vibration and noise.I guess I'm going to pull the top off this engine and check valve clearance.Any suggestions what it might be or had the same problem please let me know.Thanks in advance