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TECHNICAL MOTOBRICK WRENCHING In Remembrance of Inge K. => The Motobrick Workshop => Topic started by: Pagman on October 01, 2012, 09:41:27 PM
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I'm trying to diagnose the issue of my '86 K100 overheating. The temperature light turns on after a few minutes of riding. The fan doesn't turn on so I'm starting from there. I read in my Haynes manual (pg. 123) that testing the thermostat is the first issue to rule out. I did as they suggested, suspend the thermostat in a pot of water and heat it up to see if the thermostat opens. I think that's a bit unusual being that opening it up needs a bit of pressure from the other end (as in the picture of me pressing it opened- ouch!). Anyhow, as the thermostat sat in the pot, I brought the water to a boil. Thermostat for dinner, anyone? :laugh Anyway, at this point, should the thermostat have opened? Because it did not. I felt a bit silly doing this in my kitchen, but I needed to know if an improper working thermostat is the cause of my overheating. If the thermostat has malfunctioned, would that prevent the fan from coming on? As it boiled, the thermostat looked the same as in the picture of it standing alone. Any help is appreciated.
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opens If you`re warning lights turns on and the fan haven`t started, you got a problem with fan or this circuit.
The fan should start at 103oC, the warning light comes on at 111oC.
Since the warning light comes on, it seems that your sensor and heat management relay functions OK.
It`s not unusual that the fan is seized.
BTW. The thermostat opens in the opposite end, from where you press it open in the picture.
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opens If you`re warning lights turns on and the fan haven`t started, you got a problem with fan or this circuit.
The fan should start at 103oC, the warning light comes on at 111oC.
Since the warning light comes on, it seems that your sensor and heat management relay functions OK.
It`s not unusual that the fan is seized.
BTW. The thermostat opens in the opposite end, from where you press it open in the picture.
Does this mean the thermostat is ruled out as being faulty?
What would seize the fan?
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From what you have described, it looks like it`s the fan or related circuit that is the problem.
But it could be that your thermostat also don`t functions correctly, if you still have the thermostat out
it would be a good idea to run another test......and watch the correct end.........happy meal.
Inge K.
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What would seize the fan?
High pressure washing equipment, used from the front of the radiator...........usually.
Inge K.
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What would seize the fan?
High pressure washing equipment, used from the front of the radiator...........usually.
Inge K.
Wow, i did use the jet spray option on my hose nozel to clean out the bike. It's a regular garden hose, not a pressure washer. Could this have seized the fan? If so, how do i undo it?
What am i supposed to watch for on the correct end of the thermostat? I thought the spring was supposed to retract as in the picture of me holding it down.
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Your fan could be seized, to check...try to rotate the fan blades...it should move very smooth.
It could be other problems involved......common problem, melted brush holders...due to a partly
seized fan.
The fan motor is far from waterproof........take care when using high pressure equipment in this area.
Your wash with the garden hose is quite OK.........could be a idea to run the fan afterwards (when it functions).
About your thermostat....look at the part located at red line.......when getting close to the boiling point.