Mitch at geomag wrote in about a missing thermostat w/ his engine.

Well, my dual port 1600 didn't have one either.  Yesterday was the coolest
morning we've had since (?April?) at about 29 (faren.).  My engine would 
not idle, and did not run normally for quite a while.  I diagnosed this as
an icing carb and the lack of a thermostat/supporting tin.  I feel 
a bit uncomfortable driving the bus without the proper thermostat and will
prolly hunt one down this weekend..

christian