Last Fall when I took my 2009 Vulcan 900 to storage I noticed a very small drip of coolant on the front cylinder head. I took the bike out of storage and investigated it a little more yesterday, although didn't notice any more dripping there is a white residue like corrosion on the thermostat housing. I took the bike out for about 40 minutes and it seamed to run/ride fine but noticed the sweet/sour smell of antifreeze when I returned home. I am wondering do you guys recommend a coolant flush and a new thermostat and "O"-ring change or am I good to go without concern? Also if I do need to change the thermostat is there a less expensive one out there besides the OEM? I would appreciate any advice.