Yesterday, I managed to get the coolant filler plug un-stuck from the Solo engine in the Columbia. Much to my dismay, I stuck a wire down the hole to act as a dipstick, and found that the water jacket was bone-dry.
This is bothering me a bit.. where did the coolant go? Guess it's possible that the previous owner drained it before the bike got parked, but not bloody likely. Does the coolant level in these bikes naturally go down over the course of time? Doesn't seem like it should.
Filled it with coolant, about 2/3 water to 1/3 prestone. The drain plug is also seized.. I got it it move a little, but it started to bind up as I unscrewed it. Tightened it back down and left it.
The bike did sit for 24 years, so the truth of the matter is lost to time. I guess I'll find out when I have it up & running around. Maybe there is a leak in the head gasket, or in the outer o-ring seal on the water jacket. Not sure about the design, but I don't think the base gasket can leak coolant.