Fired up my bike for the first time in about four months without touching it. After getting some juice in the battery, she fired right up. I let her sit at idle for about 15-20 minutes tops. Got my helmet on to get her moving and my temp was redlined. Turned her off and I heard the dreadful sound of my precious coolant hissing and kissing the ground. My predicament is that I replaced the t'stat this past summer, along with my coolant. The temps here in GA have been pretty low around 20 or less. Could this cause my t'stat to stick? Or am I having a blonde moment and she idled too long? Any help is always appreciated. Glad to atleast be back on the bike....almost.

 

sounds like you idled for way too long. My bike overheats in the winter too if I don't get airflow over the radiator. Whether this is normal or not, I dont know

 

I had a similar experience. I fired mine up after sitting for a month or two in the garage, here in MI its been cold for a while too... I let her idle for about 15-20 like you and noticed the same thing. Temp was way up and heard my cooling fan come on for the first time EVER! I rode it a week or two later, when the roads melted off and it was above freezing, and it was fine for the hour or so i had her running and moving in a normal manner. I vote too long idle time as well....

 

I'd check the thermostat and your cooling fan and make sure they are both working properly. It sounds like either the thermostat didn't open up and let the hot fluid circulate into the radiator, the cooling fan didn't turn on, or both.

 

You should rig the fan to stay on (just a simple wire jumper), then let it idle for about the same amount of time. If it's still overheating or getting hot then you've got a thermostat sticking problem.... or something way worse. But just start with the basics.

Also, check your coolant for oil, and your oil for coolant just to be safe.

 

Was the fan turning on? Seen it many times on these where the temp switch on the left side of the rad goes bad. Take the wire that plugs into the temp switch on the rad & ground it. The frame is right there or you can touch it to the rad since the switch grounds through the rad anyway. If the fan does not come on then there is a wireing issue. First check the fuse. If it does come on then I think you switch is bad. It should not over heat if the cooling system is working correctly. I can let a bike run for 20-30 on the bench with no air circulation with no problems. Make sure the coolant & oil are clean & topped off. Sounds like you got some air in the system as well.

 

It's really important that the coolant be topped off. If it's low, then the radiator doesn't get hot enough at the top, where the fan switch is located, to turn on the fan. The low coolant can allow the engine to overheat. The radiator cap has to be in good condition as well. It keeps the system under pressure, around 15psi. This pressure raises the boiling point of the coolant so that it doesn't boil over. The boiling temperature of a 50/50 mix of water/coolant is about 106 C / 223 F, but with 14 to 15 psi, it raises it another 45 F. That's how it withstands the high temps of the engine.

 

The fan temp sensor is actually located on the lower part of the radiator on the left side. I believe the F2 is on the front lower left & the F3 is on the lower left rear.