Early 2000's 650 GS

[72r60/7]

A friend has cooling problems (overheating in traffic) with his 650 GS. Before he has to haul his bike a long distance away to a BMW Dealer, can you Single boys suggest a few home diagnostic checks so he can be better informed and knowledgeable when he shows up at the dealer. The fan does spin freely.
I'm trying to teach him to try and do as much for himself as he can. Most people, me included, are more than willing to help you if you are trying to help yourself first.
Thanks in advance.
Charlie

 

[henzilla]

Does the fan actually come on at some point? Spinning good, but does it run?
There also is a thermostat located in black housing on left side.

 

[pglaves]

First he should check the coolant level. Then he should make sure the radiator isn't covered with insulating and obstructing bug guts. Then he should test the fan.

Test one is to run test leads to the fan connection to make sure the fan motor actually runs. If the fan comes on, then test two is to determine if the bike electrics can turn the fan on. Let it idle until the fan comes on, or should and doesn't.

 

[72r60/7]

Update: 2002 650 GS

Henzilla

Does the fan actually come on at some point? Spinning good, but does it run?
There also is a thermostat located in black housing on left side.

Fan spins freely with bike off. He thinks that he has not heard the fan come on but lives in the country so will have to double check. Seldom sees condition that consciously is aware that the fan is running. His second observation after the warning light was "I don't think the fan is coming on". Will get him to verify

PGlaves

First he should check the coolant level. Then he should make sure the radiator isn't covered with insulating and obstructing bug guts. Then he should test the fan.

Test one is to run test leads to the fan connection to make sure the fan motor actually runs. If the fan comes on, then test two is to determine if the bike electrics can turn the fan on. Let it idle until the fan comes on, or should and doesn't.

Should have given more information initially:
Coolant in main reservoir was 1/2 cup +- low and expansion tank was at low mark cold.

Radiator crud is a good thing to look for. I the fan doesn't come on when bike is running, is there a way to check thermostat statically (in place) or a way for the average owner with a basic mechanical ability can check a relay, if the trouble shooting continues ?

Have mentioned for a few years that he needs a model specific manual.

 

[henzilla]

Testing fan with a 12v source would be a reasonably easy task with a set of small alligator test leads. Unplug from harness and hook directly to a 12v source.

Before testing the fan off line, it should come on at idle maybe within 5 minutes depending on outside temp...sometimes a bit longer.
The thermostat issues I have dealt with were from a broken tab holding the spring of the thermostat in place, leaving it wide open. Have to pull large clip from housing to remove the unit. Not usually an overheat issue as much as the non running fan.

 

[rdalland]

If he is overheating in traffic, it is likely a fan issue.

I recently had an overheating issue with my '06 F650 Dakar. The temp light would come on when I was in the woods or on class 4 roads. Cruising around town and down the highway things were fine.

I ran power directly to the fan and it worked as expected. I held the throttle with the engine at 2000 rpm's and the fan came on after a couple of minutes. I let it continue to run at idle and the fan shut off after a minute or so. Seemed like all was good.

The same thing happened next time I was off road, temp light came on and a little coolant out of the radiator. When I got home I pulled the fan off the bike and connected it directly to a battery. It ran fine for about a minute, then got hot and stopped. I let it cool and ran it again. Same result except this time the wire I used to connect to the battery started to melt the insulation off the wire. So while the fan initially seemed fine, it wasn't.

A new replacement fan is about $300. They have discontinued the old style fan and replaced it with a larger fan that is used on the newer G650's. You need a new fan shroud as well.

The fan from the K1200 is a direct fit and these can be found used on eBay pretty cheap. The model number is different than the F650 fan so I don't know what the difference is. It works fine on my Dakar.

There is a thread here from f650.com - http://f650.com/forum/showthread.php?29169-06-Cheep-Cooling-Fan-Replacement

 

[72r60/7]

2002 650 gs

Thanks folks, that should certainly get him started. Will prod a wee bit and will get back with update. May take a while, but I will get back.
Thanks
Charlie

 

[Ibgary6]

Update: 2002 650 GS

Henzilla


Fan spins freely with bike off. He thinks that he has not heard the fan come on but lives in the country so will have to double check. Seldom sees condition that consciously is aware that the fan is running. His second observation after the warning light was "I don't think the fan is coming on". Will get him to verify

PGlaves


Should have given more information initially:
Coolant in main reservoir was 1/2 cup +- low and expansion tank was at low mark cold.

Radiator crud is a good thing to look for. I the fan doesn't come on when bike is running, is there a way to check thermostat statically (in place) or a way for the average owner with a basic mechanical ability can check a relay, if the trouble shooting continues ?

Have mentioned for a few years that he needs a model specific manual.

Search YouTube for "BMW G650GS coolant change". It shows how to remove and clean the thermostat, which can stop working if crud builds up on it.

Sent from my HTC One_M8 using Tapatalk

 

[sgborgstrom]

It has been a while since I had a similar issue with overheating in traffic but here goes...

There is a small coolant bleed screw near the top of the cylinder head assembly that will allow a bubble of trapped air to escape from the high point in the system.