Ok,
I have an '09 SYM HD 200. I drove the heck out of it, and loved it since 2010. Something like 21K mi on it. After a point, I had a serious issue getting it started. Attempts to start it always seemed to cause an overflow from the coolant overflow tube.
We cleaned air filter and the carb as best we could (wife rebuilt it with significant care), but in looking things over, discovered that there was serious corrosion in the cooling system. We replaced the thermostat, the water pump cover, the coolant, and several hoses, and still couldn't get it to start. At another point, with enough fiddling with the carb settings, we were able to start it briefly while holding the throttle open. Examining the moisture that came out the exhaust, it smelled like coolant. We fear the worst.
We're afraid the next steps are replacing the cylinder head, and we aren't at all sure that's something we want to take the time to do ourselves, and we can't find a mechanic who'll look at it.
We're thinking seriously about selling this thing for parts. Thoughts?