Ok heres the back story. The rad had a few leaking lines in the water jacket so i chopped & plugged em per CG's recommendations. For the last month its been running great. No leaks or overheating problems. Everything works like it should.
4 days ago it started overheating for no reason. At stoplights it will heat up to 106-109C in fair cool weather and the fan cannot bring it down like it should. Yes it is turning on around 103c. At speed the temp goes down to the low 80's so the water pump seems to be working. Checked the thermostat it comes on at around 85C and drops the temp down to 75C before climbing again. It does seem to heat up fast in cold weather though. What do you think it could be? There is no white smoke out the exhaust so i don't suspect a cracked block\head gasket. Also theres no lost coolant either i checked this yesterday.
My mechanic recommended replacing the thermostat before bringing the bike in to be checked as its a cheap, easy thing to do first before anything else. So i just got a thermostat off brad at the chopshop and will install it this weekend. Any other theories?