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post #1 of 10 (permalink) Old 11-29-2009, 07:15 PM Thread Starter
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Cooling problem

I just picked up a '03. I took it out today for the first ride after getting it home. The low fuel light came on so, I exited the freeway and drove several blocks to the Costco. I topped it off with 91 octane and headed home. I noticed that I smelled smoke. At the next light I could see a little smoke, I turned around and it was coming from the exhaust on my bike! The temp was around 217, and I did not hear the fans. I took it easy going home. I was able to keep the temp between 209 and 219. I got it home and the fans never came on. I pulled off the lower fairings and grabbed a multimeter. I measured 12 volts at both fan plugs. I pulled out one of the fans, made a jumper wire and connected it to the battery. The one fan turned fine. I pulled out the fan relay and it tested good. It looks like the negative for the fans comes from the ECM. I found a thermosensor in the service manual. I'm thinking that the thermosensor is either bad or the connection came loose. It looks like I need to remove the tank and throttle bodies, and drain the coolant to get to the thermosensor. Any thoughts or suggestions before I tear the bike apart? Oh, I fired the bike up after the temp dropped below 150. It idled fine and the smoke was gone.

Thanks in advance,
Daris

Last edited by darisb; 11-29-2009 at 07:18 PM.
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post #2 of 10 (permalink) Old 11-30-2009, 12:16 AM Thread Starter
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I just went out to the garage to run another test. With the connector to the thermosensor unplugged, both fans come on when the key is turned on. I tested continuity on the green wire with the sensor unplugged and it is 0 ohms. When I plug the sensor in, the fans do not work. I am not sure what temperature the fans are supposed to come on at, but I would assume that they would start spinning on our around 200 degrees.
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post #3 of 10 (permalink) Old 11-30-2009, 06:33 AM
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'02 and above (SP2's) can control is through the ECM. I have a SP1, and with the stock sender Different set up), the fan comes on around 104c (219f), so you didnt quite get it up to temp for the fan to kick in.

A easy way to test, is let it run and heat up. Keep an eye on the temp and it should come on around the 220 mark for you. If it doesnt, it may be the wire from the ECM to the relay; search the forums for the wiring diagram, or PM me if you want it, to find out which wire it is and see if there is change in voltage at 220. I am not sure if the ECM grounds the fan relay, or supplys voltage to kick it over; there would have to be a SP2 member here who would know.

I run mine on 98 octane fuel (I think it is a little different in Australia), but notice it run a few degrees hotter and slower on the lower octane when I have had to use it.

You may be able to get to the thermostat and sensor with only removing the airbox; depends on how big your hands are. While you have it all apart, it would be a good time to fit a bigger airbox
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post #4 of 10 (permalink) Old 11-30-2009, 09:36 AM Thread Starter
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It appears that I did not get it hot enough for the fans to come on. Now that I'm not worried about having overheated it, I remembered that the FI light was on. I'm going to check the valves and the plugs while I have it apart, and then put it back together. I need to read through the section in the manual regarding pulling the FI fault codes.

Last edited by darisb; 11-30-2009 at 11:49 AM.
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post #5 of 10 (permalink) Old 12-02-2009, 07:40 AM
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In one of the RC foums, I believe fireblades, there is an extensive thread with pics and part numbers pertaining to SP1 thermo-switch. The SP2 has a sending unit that sends a temp reading to the ECU. The SP1 has a thermostat electric switch that directly turns the single fan on without a relay (which is used on the SP2 for both fans).
I believe the switch came from a Nissan and it is a cheap part one can ordr from an auto parts store. It has the same threading and wire terminals and switches on at a slightly lower temp 205/210? Do a search I may have referred the link to that thread here before!
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post #6 of 10 (permalink) Old 12-02-2009, 11:34 AM Thread Starter
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Thanks for the reference. I read that post and it was very interesting. Since I have and SP-2, it looks like I need to put a manual switch in. As long as temps are normal, I might just leave it the way it is. I need to get a Speedohealer in first.
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post #7 of 10 (permalink) Old 12-03-2009, 06:04 AM
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I have done that, and it works well: fan cuts in at 87c (189f) and turns off at 84c (183f). I run a synthetic coolant (penrite) which seems to keep it cooler than just glycol based products, with the benifit of it not being slippery if it gets on your tyre. I have also installed the fan of a fireblade, which pushes instead of pulls, turning the stock direction of the motor. The fins are different, and it works better than just reversing your fan or polarity on the motor.

There are aftermarket temp control units that are adjustable... they usally have a copper probe that sits in one of your rad hoses. Works well in theroy, you could set it to overide the ECM, but would look ugly as shit

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Originally Posted by ZeroGara View Post
In one of the RC foums, I believe fireblades, there is an extensive thread with pics and part numbers pertaining to SP1 thermo-switch. The SP2 has a sending unit that sends a temp reading to the ECU. The SP1 has a thermostat electric switch that directly turns the single fan on without a relay (which is used on the SP2 for both fans).
I believe the switch came from a Nissan and it is a cheap part one can ordr from an auto parts store. It has the same threading and wire terminals and switches on at a slightly lower temp 205/210? Do a search I may have referred the link to that thread here before!
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post #8 of 10 (permalink) Old 12-04-2009, 12:54 AM
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Hey stu with the fan cutting in at 87 wouldn't you be riding round with it on all the time? I'm in brisbane also and my SP1 runs between 85-95 most of the time, in traffic its abit hotter 98-104.
I've found when the fan comes on the temp drops within a minute or so.
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post #9 of 10 (permalink) Old 12-05-2009, 04:55 AM
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Today was around 33, with say 80% humidity?

Took it for a blat over Glorious, most of the time it sat on 83 to 84. the only time it got up in temp was when I was sitting behind a car comming back up the hill, and it got to 89. Once I was around the car, it dropped pretty quick, and the on the trip back down the hill, it dropped down to 79.

The fan takes a little longer to cool in traffic, as it is blowing, but if it comes on whilst you are riding, it is helping the natural air flow, not fighting it as with the stock fan.

I will admit the temp is a little low to what I would like, which is fan on around 95 and turn off around 90, but havent been able to find a switch with the right thread and temp range. I tried a few others before this one, and it did keep the fan on all the time, as it didnt cut off till around 75 (sender stated 85).

Also, I am running synthetic coolant, and I think that helps a lot. I just got tired of frying my nuts and bike in traffic
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post #10 of 10 (permalink) Old 12-05-2009, 10:33 PM
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Thankfully I don't do much riding in traffic, I'm not sure how much commuting I could take on the SP.
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