Overheating question

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m4ximusprim3

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Well, two questions actually. Got back from a ride today and noticed that steam/coolant was coming out of the overflow tube. Looked under the seat and low and behold, water in the coolant tank is boiling. After it stopped and the bike cooled down, I checked the level and it's still right at "full", so I don't think I lost much if any coolant. The idiot light on the speedo never came on.

1) With the bike running (and off, but with the key in the "on" postion) the fan wasn't going even though the water was boiling. It should be, right? Or is the water in the coolant reservoir not indicative of actual engine temp? It seems like usually when the bike was even remotely warm the fan was on, but I never paid much attention before.

2) I have a straight through TBR slip on but no jet kit- do you think the potential lean condition is causing the engine to run hotter than normal? I have a jet kit planned, but I'm thinking now that maybe I should bump it up in my list of priorities if it's making the engine run too hot.
 
m4ximusprim3 said:
Well, two questions actually. Got back from a ride today and noticed that steam/coolant was coming out of the overflow tube. Looked under the seat and low and behold, water in the coolant tank is boiling. After it stopped and the bike cooled down, I checked the level and it's still right at "full", so I don't think I lost much if any coolant. The idiot light on the speedo never came on.

1) With the bike running (and off, but with the key in the "on" postion) the fan wasn't going even though the water was boiling. It should be, right? Or is the water in the coolant reservoir not indicative of actual engine temp? It seems like usually when the bike was even remotely warm the fan was on, but I never paid much attention before.

2) I have a straight through TBR slip on but no jet kit- do you think the potential lean condition is causing the engine to run hotter than normal? I have a jet kit planned, but I'm thinking now that maybe I should bump it up in my list of priorities if it's making the engine run too hot.
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Do the fans activate when you first start the bike?
 
I don't believe so. Under what conditions should it turn on? When I turn the key to on, they don't start. When I start it in neutral, no fan. What other cases should I test?
 
You'll need to check your connections then because on the GenI, as soon as you start the bike, the fan should turn ON as sort of a diagnostic test. Once the bike is shifted into first gear they turn off. If you have no fans on startup something is wrong. I would check your connection first. It may just be dirty. If the connection looks good, see if you could apply 12volts straight to the fan to make sure it works.
 
Ok, so the fan works fine when connected direct to the battery. However, a voltmeter at the fan connector under the tank shows that there's no love when the key is turned on or when the bike is idling in neutral at first start. I saw in another thread that there's a fan fuse and a fan relay- where would I look for the fuse, and how would I check to see if the relay is functioning properly?

update: found the fuse, that's fine. i guess this means bad relay?
 
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The fuse location will be in your owners manual, the one that should of came with the bike! ,I have the gen 2 so I am not of any help,But I would check the fuse before doing anything else
 
I'm no longer on my 01' so it's been a while. I may have a manual around here somewhere to help you out. I'd start the bike, and let it sit and idle to see after 5 or 10 minutes or so if the fan kicks on. Meantime, I'll look for my manual.
 
Unless you are in traffic the fans shouldn't be turning on anyway, there is enough air flow at normal speeds to keep the temps down. I wonder if you have a blockage of the radiator or within the hoses. I'm not sure at what temp the Gen I fans turn on during normal operation, but on Gen II it's about 212 degrees which is rarely seen except in traffic, even here in TX.
 
Evitzee said:
Unless you are in traffic the fans shouldn't be turning on anyway, there is enough air flow at normal speeds to keep the temps down. I wonder if you have a blockage of the radiator or within the hoses. I'm not sure at what temp the Gen I fans turn on during normal operation, but on Gen II it's about 212 degrees which is rarely seen except in traffic, even here in TX.
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I'm wondering if maybe it was just the situation I put it through. I went on a spirited high rpm ride which ended a half mile from my house- on that half mile, i went very slow as it's potholed and then immediately turned the bike off.

Maybe the bike was running hot and then I didn't give it enough speed/airflow to cool down before I killed it at the garage? It still seems like the fan should have come on at some point, but the boiling point of water is 212, so maybe I was right around that point and the fan was just slow to come on.

I would still like to be able to check the relay for my own peace of mind- if anyone knows how to do this, I'd be appreciative.
 
m4ximusprim3 said:
I'm wondering if maybe it was just the situation I put it through. I went on a spirited high rpm ride which ended a half mile from my house- on that half mile, i went very slow as it's potholed and then immediately turned the bike off.

Maybe the bike was running hot and then I didn't give it enough speed/airflow to cool down before I killed it at the garage? It still seems like the fan should have come on at some point, but the boiling point of water is 212, so maybe I was right around that point and the fan was just slow to come on.

I would still like to be able to check the relay for my own peace of mind- if anyone knows how to do this, I'd be appreciative.
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Simply done, just start the bike and let it idle for about ten minutes. With no air flow through the radiator, the fans will kick in when she's up to max temps. Just pull up a chair, relax and wait. If they come on you know that the problem was that you shut it off just as you reached the max temperature that particular day. If they don't, and she starts to boil over again, I would check the relay, or your temp sensor.
 
Alright, so I haven't done the idle thing (TBR exhaust and wife is still sleeping), but a friend was able to check his service manual and let me know how to check the relay and it appears to be faulty. It seems like a fairly cheap part, so I'll just order one up to be on the safe side and call it good :)
 
You should get Pryogenic (Gen I) to tell his story of radiator overflow tank and what he noticed as far as overheating which happened in the middle of our trip on the Pyro twisted tour of Texas in the hill country.
 
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