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Discussion Starter · #21 ·
thermostat

Well I still have not bought thermostat. The bike is never over heating the fans just stay on. I would like to know if someone can say for sure if their fans are running or not at highway speeds in 90 plus deg weather. Not a guess, I am starting to believe its normal. 210 is where it stays. 70 to 80deg no issue fans cut off. I have 77k on engine now and have replaced fans, because top fan motor failed. I felt top motor failed because its to close to header pipe. So I put a piece of heat insulation material on back of motor.I see this material rapped on sensors on the truck engines I work on. Point I am getting at is could the fan have failed because how often it is running. Or is it just normal.
 

· Noel
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Well I still have not bought thermostat. The bike is never over heating the fans just stay on. I would like to know if someone can say for sure if their fans are running or not at highway speeds in 90 plus deg weather. Not a guess, I am starting to believe its normal. 210 is where it stays. 70 to 80deg no issue fans cut off. I have 77k on engine now and have replaced fans, because top fan motor failed. I felt top motor failed because its to close to header pipe. So I put a piece of heat insulation material on back of motor.I see this material rapped on sensors on the truck engines I work on. Point I am getting at is could the fan have failed because how often it is running. Or is it just normal.
Don't know for sure about the longevity of the fan motor, but given that it is constantly running in hot hot weather and the temps are being maintained, possibly the relay is still an issue, or maybe not as it's commanding the fans to work in helping maintain optimum temps and you say they don't run at low or cold start conditions, so likely the relay is still OK.

My ZX14 fans kick in at 203 and cut off at 195, in hot and stop & go traffic it's often cycling up and down.

Given the technical / engineering explanation above, I wonder if the water pump might have a broken impeller, IIRC that has happened in the past rare, but possible, more expensive proposition to replace on a whim.

If you're thinking the Stat is not opening enough to get the right flow, start with an experiment by pulling it out of the housing get some fresh o'rings, gasket and reassemble sans T-stat.

Fresh fluid, properly filled and purged of air gap.

Run her through a short and then longer ride cycles, hopefully in the Texas climate you won't have much of an issue with under temp conditions.

Log the temps and tell us what happens.

If nothing adverse happens, like continuous under temps and engine won't get past low temp rev limit, then might have confirmed the pump and radiator are working and your suspicion of a bad Tstat is likely on point.

Replace the Tstat with a salvage unit and see the impact.:2cents:
 

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Well I still have not bought thermostat. The bike is never over heating the fans just stay on. I would like to know if someone can say for sure if their fans are running or not at highway speeds in 90 plus deg weather. Not a guess, I am starting to believe its normal. 210 is where it stays. 70 to 80deg no issue fans cut off. I have 77k on engine now and have replaced fans, because top fan motor failed. I felt top motor failed because its to close to header pipe. So I put a piece of heat insulation material on back of motor.I see this material rapped on sensors on the truck engines I work on. Point I am getting at is could the fan have failed because how often it is running. Or is it just normal.
Somewhat. The fans come on at 217-220 and will or should turn off at 208. If you cannot drag the temps back to 208 so the fans will shut off, they will remain on steady at 210. Sure, the more the fans run, the shorter the life span but agree the top fan gets more heat from the pipe when sitting still. Moving the heat from the pipe will be blown away from the fan so all the fans see for heat is what the rad temp is. The only time my fans will come on is idling for a while or slow moving in city traffic where they will cycle on and off as required. Going down the road cruising the coolant temps are in the 185-195 range for average ambient temps. I've only seen 200 once going down the road and that was on a stinking hot humid day in the 90s.
Are your rad fins clean? Over time they plug up with bugs. Sounds like something is killing the fans efficiency for drawing air through the rad and possibly reducing air flow through it while riding. Will the fans turn off at idle after the engine gets up to 217-220 to start them? By the way the thermostat takes 210-212* to where it's fully open, at least on the two I have tested here. They just start to crack open at 178-181 area.
Ron
 

· Noel
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BTW, it is hard to think that a manufacturer {STANT} could not engineer a replica of the defunct design, if HD is still selling housings with the OEM stat, then they have a manufacturing source who should be marketing the sub-parts to us as the needs arise.

ATTN HD Patent LAWYERS:

Get off your ass and clear this issue......can you hear me now????
 

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Discussion Starter · #26 ·
I've only seen 200 once going down the road and that was on a stinking hot humid day in the 90s. Are your rad fins clean?


Well Ron as u said on a 90deg day which I have plenty here. I run 80 to 90 mph. I have cleaned radiator, well I did not pull front cover. I may do that next and really look at it. Hey tax man I did not understand sans. And dime bag I am really starting to believe this is normal in this heat and the way I run this thing.
 

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BTW, it is hard to think that a manufacturer {STANT} could not engineer a replica of the defunct design, if HD is still selling housings with the OEM stat, then they have a manufacturing source who should be marketing the sub-parts to us as the needs arise.

ATTN HD Patent LAWYERS:

Get off your ass and clear this issue......can you hear me now????
That's the problem. It's proprietary and cannot be sold to anyone but HD. I contacted Stant and they had nothing like this and when they asked what it was for, all I got was a cricket sound from then on. As for the housing and stat as a unit, that seems to be the common method, even in auto replacements in similar design.
Ron
 

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I've only seen 200 once going down the road and that was on a stinking hot humid day in the 90s. Are your rad fins clean?


Well Ron as u said on a 90deg day which I have plenty here. I run 80 to 90 mph. I have cleaned radiator, well I did not pull front cover. I may do that next and really look at it. Hey tax man I did not understand sans. And dime bag I am really starting to believe this is normal in this heat and the way I run this thing.
Could be normal based on the higher rpm and loads with high ambient temps. However, based on your first post, I got the impression the condition is new or recently occurred and fans were turning off before at those speeds?
Ron
 

· My Last Ride
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Can you elaborate on this?

1 gallon of coolant can carry X amount of heat out of the engine, so why does it matter how long that 1 gallon of coolant stays in it? There'll be another cc of coolant incoming. For each gallon (or cc, whatever) leaving the engine, another comes in.

That's why it take a motor without a thermostat a much longer time to heat up, and in the winter it may not get to operating temp, right?
I first encounter the problem on a track car engine that was over heating for no apparent reason. The car had a large tube cross flow radiator and the engine did not have a coolant restrictor (sold at Summit and Jeg's). I made a small diameter V belt pulley for the crankshaft to reduce the water pump RPM and I installed a coolant restrictor in the thermostat housing and that resolved the over heating problem. Incoming coolant flowing at excessive velocity can cause steam pockets which leads to over heating. That is why the coolant flow was reversed on the Chevrolet SB2 engine.
 

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I first encounter the problem on a track car engine that was over heating for no apparent reason. The car had a large tube cross flow radiator and the engine did not have a coolant restrictor (sold at Summit and Jeg's). I made a small diameter V belt pulley for the crankshaft to reduce the water pump RPM and I installed a coolant restrictor in the thermostat housing and that resolved the over heating problem. Incoming coolant flowing at excessive velocity can cause steam pockets which leads to over heating. That is why the coolant flow was reversed on the Chevrolet SB2 engine.
While I have no issue with Q=mCpdT the above shows variables that can cause the problem of overheating and why without a stat. Pump cavitation, direction based can also be an issue.
Ron
 

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Discussion Starter · #32 ·
Thermostats

Ok it looks like I have found the problem. I have those screens over the air inlet to the radiator. They have been there awhile. But since I added the led to watch my fan operation I never knew how long the fans were running. So I removed the screens and took on test drive. The fans came on after about 10 miles of riding. Which is what the have always done. But this time they were able to go back off and I noticed a good drop in engine temp:). And they came on again and so forth. There definitely is a difference in the cooling fan operation. At night its even better. So I am gonna assume the screens interrupted the velocity of air flow at high speed(something like a dam or restriction) and when I would slow down the air could enter radiator better or enough to cool engine. Damn aftermarket got me again. I would have never known I had a problem if it weren't for the lights I installed. The temp gauge was steady and temp light never came on. But I bet thats why my fan failed awhile back. So thoes screens do slow air flow especially at speed. The fans now do not work no where near as hard as before. When exiting highway, fans are not on now,(100deg day) not until a while later in traffic. Now I have to be concerned about something hitting that high dollar radiator lol. Beware of the screens!
 

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Ok it looks like I have found the problem. I have those screens over the air inlet to the radiator. They have been there awhile. But since I added the led to watch my fan operation I never knew how long the fans were running. So I removed the screens and took on test drive. The fans came on after about 10 miles of riding. Which is what the have always done. But this time they were able to go back off and I noticed a good drop in engine temp:). And they came on again and so forth. There definitely is a difference in the cooling fan operation. At night its even better. So I am gonna assume the screens interrupted the velocity of air flow at high speed(something like a dam or restriction) and when I would slow down the air could enter radiator better or enough to cool engine. Damn aftermarket got me again. I would have never known I had a problem if it weren't for the lights I installed. The temp gauge was steady and temp light never came on. But I bet thats why my fan failed awhile back. So thoes screens do slow air flow especially at speed. The fans now do not work no where near as hard as before. When exiting highway, fans are not on now,(100deg day) not until a while later in traffic. Now I have to be concerned about something hitting that high dollar radiator lol. Beware of the screens!
Yes, many people on here have had problems with screens, more so with the perforated sheet style. There seems to be a significant difference with airflow on that type of screen on a system that is already airflow challenged. The diamond net style seem to give less of a problem. Glad you got it sorted.
 

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Ok it looks like I have found the problem. I have those screens over the air inlet to the radiator. They have been there awhile. But since I added the led to watch my fan operation I never knew how long the fans were running. So I removed the screens and took on test drive. The fans came on after about 10 miles of riding. Which is what the have always done. But this time they were able to go back off and I noticed a good drop in engine temp:). And they came on again and so forth. There definitely is a difference in the cooling fan operation. At night its even better. So I am gonna assume the screens interrupted the velocity of air flow at high speed(something like a dam or restriction) and when I would slow down the air could enter radiator better or enough to cool engine. Damn aftermarket got me again. I would have never known I had a problem if it weren't for the lights I installed. The temp gauge was steady and temp light never came on. But I bet thats why my fan failed awhile back. So thoes screens do slow air flow especially at speed. The fans now do not work no where near as hard as before. When exiting highway, fans are not on now,(100deg day) not until a while later in traffic. Now I have to be concerned about something hitting that high dollar radiator lol. Beware of the screens!
Well Rob, you failed to mention those bastards. It will kill flow for sure as they form a compression zone ahead of the screens slowing down flow through the rad. More so going down the road at speed.
Ron
 

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Discussion Starter · #37 ·
Yes, many people on here have had problems with screens, more so with the perforated sheet style. There seems to be a significant difference with airflow on that type of screen on a system that is already airflow challenged. The diamond net style seem to give less of a problem. Glad you got it sorted.
The diamond style is the one I had. The only way to really see whats up is w/ temp gauge and fan on lights.
 

· Asatruar
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Glad this has been resolved, I've been leery about those screens ever since people started to bling their bikes out with them.

K.I.S.S. still applies.
 
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