ENGINE FAILURE DUE TO A BINDING MIXTURE CONTROL SHAFT. THE BINDING MIXTURE CONTROL SHAFT WAS THE RESULT OF INADEQUATE MAINTENANCE WHICH ALLOWED THE ACCUMULATION OF MOISTURE AND WATER IN THE CARBURETOR TO REMAIN FOR AN EXTENDED PERIOD OF TIME CAUSING RUST AND CORROSION. A FACTOR IN THE ACCIDENT WAS THE UNSUITABLE NATURE OF THE TERRAIN FOR THE FORCED LANDING ATTEMPT.