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It's summer now, and my 83 honda cx650 has been teetering on the verge of overheating. I checked the fluid level and it is fine. My question is, how do I check to make sure the fan is working? The electrical connection seems fine, both wires are plugged in, but how do I know for sure? Also, there is a small leak from the water pump housing, I got a new replacement gasket, but I've been putting off changing it because I have to drop the engine to get to it. Could that be the reason it's getting so hot?

Thanks
 

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You should be able to run a hot wire to one of the nodes and the fan should turn on.



650's tend to have to get almost to the red before the fan turns on.



As for a weep hole leak if the bike has sat for a while then run it and it might go away. Otherwise you need a new mechanical seal and we have an easy way to do that. Just watch your leak.
 

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Also, there is a small leak from the water pump housing, I got a new replacement gasket, but I've been putting off changing it because I have to drop the engine to get to it. Could that be the reason it's getting so hot?

Thanks


This does depend on if it's the actual gasket for the pump housing or what we call the mechanical seal. Neither one requires that the engine be dropped to replace.



If it's the gasket around the pump itself I'd imagine that would prevent the cooling system from building up presure and could cause it to run hot.
 

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You should be able to run a hot wire to one of the nodes and the fan should turn on.



650's tend to have to get almost to the red before the fan turns on.



As for a weep hole leak if the bike has sat for a while then run it and it might go away. Otherwise you need a new mechanical seal and we have an easy way to do that. Just watch your leak.


Exactly this. The bike will get very disconcertingly close to the red before the fan kicks on, but when it does you can hear it, feel it, and your lights will dim momentarily.
 

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Also if you shut the engine off while the fan is running it will continue to run (and will be easier to hear -ie. know for sure that it is running) until is reaches the proper temp (as long as you don't turn the key off)
 

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The 650s run a little hotter than the 500s because they don't have a mechanical fan constantly running. On a 650 the electric fan doesn't come on until you're nearly in the red on the gauge. On summer days when it's over 85 degrees F I will have the gauge nearly reach the red and the fan cycles on and off at stop lights and in heavy traffic. It should cool off back to between the bottom and middle of the thick white line when you get underway over about 35 - 40 MPH. When it's cooler, 70 degrees F and below, the temperature runs at the bottom of the thick white line but will creep up to the middle of the thick white line at extended stop light or in stop and go traffic. You will get used to the 650 using the full range of the temperature gauge. If it isn't boiling over it isn't to hot.
 

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I put a manual over ride switch On my GL650I and am very happy with it. I just flip it on in the city and off when I leave. Yesterday we went for a ride in 33 celsius with a humadex of 43, that means hot around here, and I had the fan running on the hyway too. The temp went about 1/2 way up, but the fan took it down to normal. I believe that Honda made a mistake on the settings for the 650 fan to come on, and that is what eats staters.
 

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I am having the same leak from the water pump cover. I replaced the gasket with a brand new one, but am still having the leak. I couldnt see any problems with the cover, nor the casing where it mates. I was tempted to run a bead of silicone around the cover near the gasket, but didnt while I had it all apart.



Thoughts?
 

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I am going to replace that gasket sometime next weekend, and definitely put gasket sealer on before I put the cover back on. Hopefully this will help the water pressure. GL, how did you put that over-ride switch it? I am curious about that.
 

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It's hard to believe that the water pump cover would leak. It has no movement and is sealed with an "O" ring. You most likely have a mechanical seal leak, the small by pass hose from the thermostat to the waterpump is leaking or the chrome water pipe is leaking. I've had leaks at all three at one time or another. The mechanical seal failed from sitting unused for many years, I somehow damaged the hose between the pump and thermostat removing and replacing my carbs and For no apparent reason the chrome water pipe "O" ring started leaking.
 

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I just replaced the O-ring on the chrome pipe, and the leak was still there, so I replaced the gasket on the cover. The metal connector for the bypass hose is rusted - maybe that could cause the leak?
 

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The mechanical seal looks as though it would keep coolant from getting into the rest of the engine. My coolant is leaking to the outside of the engine.



On that page, however, it noted that the O-ring on the pipe should be "in the groove." Not on the end, before the bumps? I thought that would make the most sense for being held tightly against the pump cover...
 

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The mechanical seal looks as though it would keep coolant from getting into the rest of the engine. My coolant is leaking to the outside of the engine.



On that page, however, it noted that the O-ring on the pipe should be "in the groove." Not on the end, before the bumps? I thought that would make the most sense for being held tightly against the pump cover...


Some people use two O-rings on the transfer pipe for security.One in the groove and one on the end.On both my CX I use use one in-the-groove but it MUST be the exact size otherwise it will leak.
 

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Some people use two O-rings on the transfer pipe for security.One in the groove and one on the end.On both my CX I use use one in-the-groove but it MUST be the exact size otherwise it will leak.
Ill give that a shot, but I still dont think that the leak is coming from the chrome hose. It seems to be coming from so far under there that I cant really see the exact spot!
 

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It seems to be coming from so far under there that I cant really see the exact spot!


Almost guaranteed to be the weep hole then, I had to use a mirror to get a good look at mine too. I got to thinking - rubber seal, a little rubber rejuvinator might not hurt.



Sure enough, a shot of LPS into the hole once then again a few days later eventually stopped the leak, but only for a while, sometime later it went back to being an intermittent leak but on hot rides. It was back to leaking on a fairly regular basis when I parked it last year, wouldn't leak at all the whole time CXOkie has ridden it around this year but he replaced the seal for me regardless.



If your leak isn't too bad it wouldn't hurt to try the LPS trick. It has to be LPS or something else that has the capability of softening/revitalizing rubber, WD-40 won't work.
 

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What/Where is the weep hole? I havent heard of it, so I wont know what I am looking for.



And what is LPS?
 
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