Seetz, take out the spark plugs and see if you have a cylinder full of either water or gasoline. If the carburetor is over-flowing, you might have a hydraulic lock. A cylinder full of water also means a hydraulic lock from either the head gasket leaking, or a cracked cylinder or a crack in the head. The carburetor won't over flow unless the needle valve stays open- either stuck or held down, or the float has sunk.
It is not unusual to hear air leakage if you listen carefully from under the hood, and you turn the engine slowly, by hand. Otherwise, you probably won't hear anything.
If either the valve timing or distributor timing is off, it is quite possible to have a satisfactory spark, but the engine will not start. And, don't try push-starting until you are sure the cylinders are not full of liquid.
Harvester
