Small Engines (Lawn Mowers, etc.): CubCadet1650Kohler, blown head gasket, leaf vac

Question
Ran OK with leaf vac until idling while putting away TracVac.  Suddenly stopped in November 06. Hasn't started since.  Spark present, turns over, but acts like not getting cas.  Replaced dry rotted gas hose. Checked oil level. Carb cleaner to carburator, can see vertical movement of something rod(?) in carburator, and cyllinder head when spark plug out, when rotating the axle by hand.  valve spring broken?  If so can I replace?  How.  27 YO IH CubCadet. Hate to dump it now....

Answer
 Hello David:

 If you Pour a Small Amount of Gas Into the Carburetor and try to Start the Engine; What Happens? If this Engine has a Few Years on it, then it May be the Valves Require Adjustment. A Blown Head Gasket. Or if the Carburetor Was Not Soaked Overnight in Carburetor Cleaner; the Carburetor May Still be Restricted. Send me All the Model Numbers Off the Engine, Please. With these I can Locate the Proper Manual and Better Assist you. Hope this Helps. I am here if you Require more Assistance. Let me know what Happens, Please. Thanks.

 Good Luck

 Respectfully

 John