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Hello all, I've got a CBR 929 01" and I'm having cooling issues. Previous owner epoxy welded waterpump closed so to drain coolant I pulled off a hose and refilled with engine ice and Honda coolant after running distilled water through it. Problem is now it gets hot like 240 at times when not moving. I'll normally see 210-215 when moving. Now the previous owner did have the siphon tube that comes from radiator connected to where overflow tube goes on coolant reserve tank, I switched it back. My fan does comes on but doesn't seem to cool bike down when not moving. Any suggestions ideas would be greatly aprreciated guys thanks in advanced. Also what purpose does the siphon tube provide?
 

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Hello all, I've got a CBR 929 01" and I'm having cooling issues. Previous owner epoxy welded waterpump closed so to drain coolant I pulled off a hose and refilled with engine ice and Honda coolant after running distilled water through it. Problem is now it gets hot like 240 at times when not moving. I'll normally see 210-215 when moving. Now the previous owner did have the siphon tube that comes from radiator connected to where overflow tube goes on coolant reserve tank, I switched it back. My fan does comes on but doesn't seem to cool bike down when not moving. Any suggestions ideas would be greatly aprreciated guys thanks in advanced. Also what purpose does the siphon tube provide?

Did you bleed the air out as shown in the manual?
Not sure what you mean by "siphon tube", but the radiator overflows to the bottom of the reservoir, and then draws the coolant back as the pressure drops back to normal. From memory there are only two hoses at the radiator cap, the lower pressurised one back to the thermo housing, and the upper unpressurised one to the reservoir.
 

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Discussion Starter #3
Did you bleed the air out as shown in the manual?
Not sure what you mean by "siphon tube", but the radiator overflows to the bottom of the reservoir, and then draws the coolant back as the pressure drops back to normal. From memory there are only two hoses at the radiator cap, the lower pressurised one back to the thermo housing, and the upper unpressurised one to the reservoir.
I did burp it with rad cap off , and some bubbles did come out. It seems as if it didn't take as much coolant as manual says it would've. I rode it came back and put some more coolant, though as stated before the siphon tube was connected to upper unpressurised part of reservoir so I was always losing a bit of coolant. I included a picture siphon tube.
 

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I did burp it with rad cap off , and some bubbles did come out. It seems as if it didn't take as much coolant as manual says it would've. I rode it came back and put some more coolant, though as stated before the siphon tube was connected to upper unpressurised part of reservoir so I was always losing a bit of coolant. I included a picture siphon tube.

Okay, that is the overflow hose and should be connected _above_ the radiator cap so it it outside the pressurised cooling system.
If you have it connected to the lower nipple at the radiator cap you will not be getting any pressure in the system and are simply boiling the coolant away as steam.
 

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Okay, that is the overflow hose and should be connected _above_ the radiator cap so it it outside the pressurised cooling system.
If you have it connected to the lower nipple at the radiator cap you will not be getting any pressure in the system and are simply boiling the coolant away as steam.
I have it connected to the circled part in picture on the radiator, I have no overflow hose, but as I understand it overflow hose connects to the top part of coolant reservoir and runs to back of bike unpressurized anyway, would this mixup cause bike to overheat?
 

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I have it connected to the circled part in picture on the radiator, I have no overflow hose, but as I understand it overflow hose connects to the top part of coolant reservoir and runs to back of bike unpressurized anyway, would this mixup cause bike to overheat?

The "siphon tube" is the overflow hose.
If it is connected correctly then it's not the cause of the problem.
But coolant should not flow to the reservoir until the temperature is well above boiling point. At what temp is it dumping it to the reservoir?
 

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Discussion Starter #7
The "siphon tube" is the overflow hose.
If it is connected correctly then it's not the cause of the problem.
But coolant should not flow to the reservoir until the temperature is well above boiling point. At what temp is it dumping it to the reservoir?
I actually just connected hose to where its supposed to be yesterday and didn't get a chance to warm her up n ride because of Florida rain. When I noticed coolant under bike I was at DMV after riding her and getting her up to say 235 238 degrees and parked it when I came out I noticed coolant dripping.
 

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Discussion Starter #8 (Edited)
Update after connecting hose where it goes and burping system, I found d that although fan works it doesnt come on at 215 degrees. Also discovered that when I turn on highbeams bike temp jumps 10 degrees which leads me to think thermo switch on rad is shot, ordered a new one, I'll update, by the way thanks blade for input.
 
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