B&S 31P777 won't turn over after replacing head gasket

[RicktLawton]

I Have completed a head gasket replacement on the 18HP engine in a John Deere tractor. I set valves to .04 Intake and .06 Exhaust. When I start it it turns part way, then stops. As I continue to start it it moves a little then stops. This continues through the full engine rotation. If I remove the spark plug it cranks normally. Any ideas would be appreciated.

 

[StarTech]

Bad ACR on camshaft which would mean the camshaft needs replacing. You might even need a new governor gear.

Former Camshaft kit 793880 superseded to 84005207 which no longer has the two 690564 tappets (lifters) included. They must be ordered separately.

 

[RicktLawton]

Bad ACR on camshaft which would mean the camshaft needs replacing. You might even need a new governor gear.

Former Camshaft kit 793880 superseded to 84005207 which no longer has the two 690564 tappets (lifters) included. They must be ordered separately.

Many thanks for your help.