Originally Posted by Wentwest
My reaction is to tell you, screw it and just ride that puppy for a while. Overheating is rare for these scooters, but the sender unit for the gauge can be faulty. It's the same as senders for Honda cars of that era, so take it to a car parts store and get a replacement. The sender is on the thermostat housing and has nothing to do with the fan on the radiator, which can run without you knowing it because it's not too loud. That has it's own sender and, yes, you can wire around it and use a manual switch. Or, just set it up to run whenever the key is on.
Anyway, I still say, ride it. Report back after 3 tanks of fuel. You should get between 60 and 70 mpg unless you really hammer it or ride only with a wide open throttle.
The head gasket blew again while test riding it for 30 minutes at around 45mph, could look down and see bubbling coolant coming out of the reservoir. I have one more I can try installing, but I'm burnt out on working this thing.
I have not put a volt meter on the thermosensor, which I bypassed with aforementioned switch today, but I have tested the thermostat, and the sender unit for the engine temp that is part of the thermostat housing. I have been riding with the front panel off, so it's been easy to just look down and see that the fan has not been spinning, the whole time I've owned this scooter, until I installed that switch. Indicated engine temps stayed in the low range until I rode for a solid 15 minutes at about 75% throttle, ~45mph. The Scooter used to do an indicated 63mph, but was struggling to hit 55 today, so I went easy on it. Didn't matter apparently...
On the bright side...! I met another ADV member today who owns a shop here in town. Picked his brain about some stuff, and probably ate up way too much of his time, lol (Sorry, man!) Good to know there are service places besides stealerships around here though.