Running Hot......

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twillet

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I have a Gen II FZ1 (06') with 50,000 miles on it. It is running hot, with some very strange symptoms.

It will run normally and at normal temps, if left idling.... but would overheat with the temp gradually climbimg from normal to 244 as the bike is ridden at steady RPM, and would immediatly overheat if stopped at a stoplight after being ridden. What i did to address this:

- Oil change,
- Coolant flush and replacement
- New Temp Sensor (The old one was indeed faulty)
- New thermostat

After this, the bike would no longer overheat, but it was still running hot....
My bike then sprang a coolant leak.... What I did to address this:

- Replace the whole thermostat housing, including a new thermostat again,
- another coolant drain and replacement.... after which I burped the system twice to make sure there were no air pockets left....

Bike still runs hot, but now with the weird symptoms..... The bike runs fine and maintains a normal operating temp af around 188-190 in 70 deg. weather at 65MPH or below, and will not overheat at stoplights.... However, once you breach that 65MPH barrier, the bike will gradually climb to 230 while being ridden, especially if your crusing at highway speeds, and will begin overheating at stops (+244 and above).......

No leaking (oil or coolant), no frothing in the coolant, no frothing in the oil, not pushing fluid out, no weird noises, and no change in ride quality.........

I am stumped at this point...... help, please.
 
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twillet said:
Strike that, I posted this in the wrong location and I can't figure out how to delete this; I'm new to forums. Sorry guys.
Click to expand...

I fixed your post to say Gen II since it's an '06. Gen I would be '01-'05. Also moved it to the Gen II section.

Now on to your problem...seems to me that there's not enough water flowing through the engine (or radiator) to cool the bike at higher RPMs. it's obviously not a fan issue because it overheats at highway speeds. Did you have the radiator serviced at all? Wonder if it's not flowing enough coolant due to some internal blockage. If radiator checks out fine then that only leaves the water pump as the culprit...
 
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No, I have not had the radiator serviced.... It is the last thing that I can think of save the water pump. I have run the bike sans radiator cap however, and once the thermostat opens, I can see coolant flowing, which leads me to believe that the water pump is functioning.

There was a fare amount of scale on the temp sensor when I removed it, so it makes sense given the mileage on the bike. I will try this and post back, thanks.
 
twillet said:
No, I have not had the radiator serviced.... It is the last thing that I can think of save the water pump. I have run the bike sans radiator cap however, and once the thermostat opens, I can see coolant flowing, which leads me to believe that the water pump is functioning.

There was a fare amount of scale on the temp sensor when I removed it, so it makes sense given the mileage on the bike. I will try this and post back, thanks.
Click to expand...

In addition to servicing the radiator it may not be a bad idea to run some coolant flush product through the cooling system. It's meant to remove these deposits, but wont totally unclog things. Sounds like that coolant wasn't changed for the entire 50k miles :(
 
The coolant was changed three times, for track days where I ran only water. I did run some cooling system flush through it when I replaced the temp sensor and the thermostat the first time. It showed a slight imporvement, but nothing significant.
 
twillet said:
The coolant was changed three times, for track days where I ran only water. I did run some cooling system flush through it when I replaced the temp sensor and the thermostat the first time. It showed a slight imporvement, but nothing significant.
Click to expand...

Oh well that's good that you had changed the coolant before then. It's still very possible for the radiator to be somewhat clogged or the water pump to not be flowing enough to properly cool the bike.
 
I checked that, the cap is fine. I've had a cap go bad on this bike twice before and the bike pushed fluid out the cap once it pressurizes. Its not doing that now, but I suupose it won't hurt to check again. I'm leaning more and more towards the rad. being clogged, mostly because I want it to be that and not the water pump.... We'll see.
 
With the scale you found on the temperature sensor, a clogged radiator is a real possibility.
You might check the radiator fins for dirt -- not allowing good air flow through the radiator.
Also, with the mileage on the machine, the radiator fins may be separating from the cross flow tubes - reducing the cooling capacity of the radiator. You may be able to see this condition visually, but there is a good chance you wont be able to see it.

If it was my machine I would flush out the radiator first - using water. My experience with chemical cooling system flushes has been that they can eat away weakened (or even unweakened) cooling system metals - flow through pipes causing leaks in the radiator - making replacement necessary. Good luck with this.

It does appear that the radiator is not cooling properly. Next thought would be the water pump - but you said you saw fluid flow.

It is also possible that there is an air bubble in the system that needs to be bled out.

My thoughts...
 
The radiator seems to be the consensus opinion. I have seen fluid flowing and I've also bled the system twice to make sure that I got the air out, still having same problem. I will keep going with the radiator and post back. Thanks
 
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