I’ll just say the painful words out loud. FIND THAT SHIM! You need to confirm it’s not where it shouldn’t be. magnet stick, small magnet on a string, etc. both useful in probing everyplace you can to try and find the shim if it’s in the motor.
Did you also double check your math and final clearances of all valves before buttoning it up? When you did your double check, did you make certain you were lined up perfectly on Top Front and Top Rear marks dependent on the valve you were checking.
Did you also double check your math and final clearances of all valves before buttoning it up? When you did your double check, did you make certain you were lined up perfectly on Top Front and Top Rear marks dependent on the valve you were checking.