Motor overheating tendency on my Air-cooled Beetle obliged me to check the function of Thermostat actually. As it is covered with air guiding plate on the position between #1 and #2 cylinder, the function of the thermostat cannot be seen from the outside. Removing 4 pieces of fixing 6mm screws it could be accessed directly by hand. Though it's bellows construction performs the function to extend the length after being warmed, it stood still at the longest condition---it means just broken. Cylinder cooling air flow is not closed at the cold stage leading overcooled condition. The cooling air control has much to do with the choke and idle controlling in the carburetor construction. Extended and broken bellows has nothing to do with overheating phenomena this time, so I left it untouched.
The photo shows bellows shrunk in cool condition with air flow flaps closed.
