Overheating after a while.

[greg3852]

Got it running again. New thermoswitch and fluid. Filled the bottom hose up first, then the next until I filled the top. Squished every line, ran it until the thermostat opened. Let it cool and topped it off. Seems to be good.

@Gixer I’ll call late in the afternoon. Hate waking you up.

[greg3852]

Spoke too soon. Despite filling lowest hose first and going up, it’s still filling up the overflow bottle. It was perfect yesterday and this morning it is completely full. If I had hair I’d pull it out.

[greg3852]

This time it did not overheat. It never got past the mid point, but it did fill up the overflow bottle. Any suggestions?

[ali123]

This time it did not overheat. It never got past the mid point, but it did fill up the overflow bottle. Any suggestions?

lol... talk to the engine builder. j/k

[CBXRider]

This time it did not overheat. It never got past the mid point, but it did fill up the overflow bottle. Any suggestions?

If it filled up the overflow tank but didn’t overflow the tank it might be ok. The size of the tank is big enough to take a slight overfill w/o flowing out of the tank. The excess should drain back in after it cools down. If the tank is low when cooled, fill to the full mark.

[greg3852]

I'm going to try damn near laying it on the left side and seeing if i can get it. I'm hoping it isnt a head gasket. No loss of coolant, no smoke etc, so I hope that is ok.

[CBXRider]

Remember, although it’s a sealed system under pressure there does have to be some air in it. Filling everything up (and) topping off the overflow tank is too much. When it gets warm enough to squirt some into the tank, the tank should not be so full as too cause (it) to overflow.

[jermzfree]

Is the fan coming on now?

[greg3852]

Fan is coming on perfectly now. It was actually low in the overflow.

[jeffgordons24]

If it filled up the overflow tank but didn’t overflow the tank it might be ok. The size of the tank is big enough to take a slight overfill w/o flowing out of the tank. The excess should drain back in after it cools down. If the tank is low when cooled, fill to the full mark.

I just posted thread with I guess similar symptoms. Fresh start up after sitting for about 2 years, I had my overflow bottle off to clean it. Anyways ran the bike for 15-20 mins and it got hot, hot enough that my overflow was bubbling and I could hear some hissing like either air in system or something else I dont know hoping you sorted your issues out.

[greg3852]

Not yet, but I think my issue may be a head gasket. I've tried everything to get air out of the system. I've damn near laid it on the left side (which did get out a couple of large air pockets) but it continued to overheat. My issue may be different though as I'm running a 1397 which may have stretched head bolts requiring new studs. But I did hardwire a switch for my fan which allows me to turn on the fan at any point. That alone allows me to keep it running. The cold weather also helps. But I'll be doing some work over the winter on her.

[busakiller]

Do a leak down test. Pop the radiator cap off and do a leak down test. If the coolant bubbles then you have a bad head gasket. If it doesn't then maybe your radiator cap is bad.