Overheating solved by bonehead

Yeah, I'm the bonehead... Out for a ride last weekend and stuck in a massive traffic jam. Temps started to climb, eventually to 250, where the gauge flashes. I pulled into a parking lot to let it cool, then turned around and went back home. Temps were fine underway. Got home and tested it at idle. At 220, the fan came on, but temps kept rising anyway, eventually to 250 again. I researched here and figured I'd be ordering a radiator cap and thermostat, and getting enough coolant for a flush, etc. In the past, I checked the overflow tank and filled it when it was low - it was empty this time. So I filled it thinking (ah ha), it was just low on coolant. After idling a while, it overheated again (in 75 degree weather). So, in preparation to drain and flush, I took off the RH fairing. Now, I've never had this fairing off before since to change the oil, fix the R/R, check coolant, etc I only needed to take off the LH fairing. Seeing the radiator cap on the RH radiator I began to feel silly. Yep, I opened the cap, filled it up ( a quart low), started it up and it warmed to 220, where the fan came on and temps dropped to 200. Doh! So, the moral of the story is, for overheating issues, make sure the radiators are full! And don't depend on the overflow tank to add coolant to the system like some cars do. Sheepishly riding again.

 

You will learn as you go.........Ride safe

 

Was this a one off and did this fix your situation, have you checked your coolant level in the radiator to see if it has dropped since ?

The same thing occurred to me last week where I got stuck in halted city traffic on an unseasonally hot day ( 28C / 83F ) last week where the Fan failed to come on and my engines temp slowly rose to 120C ( didn't get to red 122C ) before I parked.

After riding home via Freeway the engine Temp stayed low. After arriving home inspected the coolant in the overflow bottle found all the coolant had totally disappeared ( overflow bottle level was normal level when checked day before ) and the radiator water level was down a few inches from cap. I tested the fan was working fine by shorting to Ground then after a complete coolant change and burping the Fan is operating as expected again at about 104.5C, although I'm a bit puzzled why this has occurred although the Radiator caps rubber seal looks a little dodgy so might replace, any ideas and what I may need to check further noting I also performed an oil change afterwards and no sign of water in it or oil in the drained coolant ?