[GlenM]

When recently acquiring 2007 w/2515 miles, drove it 5+ miles, did not overheat.
Flushed coolant system 8 times before drained clear.
Now, after 8+ minutes idling, guage goes to 3/4...after 1 minute warmup, can ride 7 minutes before guage goes up.
Radiator cap is still cold.
Would this be thermostat not opening?? or, water pump not pumping ???
Any help would be greatly appreciated !

 

[Itinifni97]

Only 2515 miles on it, a lot of life left in that bike! I have 72k on mine.

There are a lot of things that can cause overheating but lets start with the symptoms.
Is it actually overheating or is the gauge just going higher than you expected?
What happens if you leave it idling longer than 8 or 10 minutes, does the gauge continue to climb or does it boil over?
Does the radiator fan ever come on?
How about if you ride for a longer period, does the gauge start to go down?

Considering the age and lack of miles on the bike a thermostat replacement wouldn't be a bad place to start but may not be the root cause.

When you flushed the cooling system I assume you were just using water, is that correct?
Would you please describe how you flushed it, just a simple fill and drain or did you purge the system each time opening the air bleed bolt to let the air out then running the engine a few minutes before draining and repeating?

When you did the final fill did you remove the air bleed and leave off until coolant ran out then install the bolt and top off the coolant (if not you could have a air pocket trapped at the thermostat)?

Assuming the system was flushed and filled properly I would definitely start with thermostat replacement if for no other reason that it's 16 years old.
Once that's done if the issue persists I'd take a look at the radiator, if you have access to an inferred thermometer or thermal camera you can quickly check to see if it's getting hot. You can also do a quick touch check near the top and bottom of the core.
My bikes are all in storage now so I can't take a look at the YP to see but if you can reach the upper and lower radiator hoses you can also get an idea if there's any coolant flow by feeling them. Just be aware any of these components may be hot.

It's possible there are more serious issues like a blown head gasket or non-functional water pump but I doubt it at that mileage.

 

[GlenM]

Only 2515 miles on it, a lot of life left in that bike! I have 72k on mine.

There are a lot of things that can cause overheating but lets start with the symptoms.
Is it actually overheating or is the gauge just going higher than you expected?
What happens if you leave it idling longer than 8 or 10 minutes, does the gauge continue to climb or does it boil over?
Does the radiator fan ever come on?
How about if you ride for a longer period, does the gauge start to go down?

Considering the age and lack of miles on the bike a thermostat replacement wouldn't be a bad place to start but may not be the root cause.

When you flushed the cooling system I assume you were just using water, is that correct?
Would you please describe how you flushed it, just a simple fill and drain or did you purge the system each time opening the air bleed bolt to let the air out then running the engine a few minutes before draining and repeating?

When you did the final fill did you remove the air bleed and leave off until coolant ran out then install the bolt and top off the coolant (if not you could have a air pocket trapped at the thermostat)?

Assuming the system was flushed and filled properly I would definitely start with thermostat replacement if for no other reason that it's 16 years old.
Once that's done if the issue persists I'd take a look at the radiator, if you have access to an inferred thermometer or thermal camera you can quickly check to see if it's getting hot. You can also do a quick touch check near the top and bottom of the core.
My bikes are all in storage now so I can't take a look at the YP to see but if you can reach the upper and lower radiator hoses you can also get an idea if there's any coolant flow by feeling them. Just be aware any of these components may be hot.

It's possible there are more serious issues like a blown head gasket or non-functional water pump but I doubt it at that mileage.

I flushed the coolant system 8 times before it drained clear…each time I had a radiator flush mixed with water.. and..always removed bleed bolt when filling. Put bleed bolt back in as
antifreeze was running out.

Literally sucked mud from overflow tank the first couple flushings…ran engine each time after draining/refilling..
The fan comes on just before the guage jumps from ½ to ¾ …The radiator cap remains cold, indicating to me water not circulating. So, will begin tear down in a couple of days to get at the thermostat, hopefully won’t have to deal with water pump.

Really like the thing and learning a lot on the tear downs!

 

[minimac]

You still may need to purge the system for air while it's running. I'd bet your thermostat is bad if you had to flush that much sludge out of it.

 

[GlenM]

You still may need to purge the system for air while it's running. I'd bet your thermostat is bad if you had to flush that much sludge out of it.

First several times I refilled, left the radiator cap off to see if it would “burp” any air pockets.

The liquid level at top of radiator would just pulsate up and down a couple of inches….never could
fathom what was going on there…??....

Then later, after running several minutes, liquid would expand and just overflow over the top….

Last several days would start engine..after 8-10 minutes guage would jump to ¾..but radiator cap
Still cold…no overflow…after cool down water would be at top.

After all this angst, hoping it’s just bad thermostat…
Thanks!!

 

[minimac]

Not at the radiator cap- at the bolt on the engine. Look in the service manual . It describes the proper way to bleed the cooling system.

 

[minimac]

I started a conversation with some information for you. Get to it near the upper right of the page here, after you sign in.

 

[GlenM]

Not at the radiator cap- at the bolt on the engine. Look in the service manual . It describes the proper way to bleed the cooling system.

I have service manual..I removed bleed bolt both when draining and refilling..on re-fill, would screw bolt back in as it was pouring out..
Thanks!

 

[scos53]

Hey Glen, I went through the whole Done Everything three times last summer/ fall . It can be very frustrating. I mean VERY FRUSTRATNG! It still has air in the system. When you bleed it, let it run for awhile Repeat. I went through 2 gallons of coolant over a period of a few weeks. It just wouldn't run right. Finally the second time I had the water pump cover off I discovered the thermostat feed line was blocked with rust from having sat for 10 years. drilled it out and problem solved after months of fighting it. Good Luck.

 

[GlenM]

Hey Glen, I went through the whole Done Everything three times last summer/ fall . It can be very frustrating. I mean VERY FRUSTRATNG! It still has air in the system. When you bleed it, let it run for awhile Repeat. I went through 2 gallons of coolant over a period of a few weeks. It just wouldn't run right. Finally the second time I had the water pump cover off I discovered the thermostat feed line was blocked with rust from having sat for 10 years. drilled it out and problem solved after months of fighting it. Good Luck.

"Frustrating" is a clean way of expressing it
I've just about used up my 2nd gallon...am taking covers/seats off now to do the same thing..check all lines around the thermostat..after all, it's 15 iyears old and only has 2500+ miles on it (hardly more than avg of 200/yr)
I'm still unsure if pump would get water to top of radiator if thermostat is stuck shut.....????
Do you remember which line(s) you found clogged ??

 

[scos53]

Hey, The line is the small one on the top of water pump cover. I had to drill it out because it was clogged solid. Was your system rusty?

 

[GlenM]

Hey, The line is the small one on the top of water pump cover. I had to drill it out because it was clogged solid. Was your system rusty?

In service manual page 6-4....did you really mean the thermostat cover?? Line 1 or line 2 or line 3 ???
Thanks !

 

[scos53]

Line 3.it is the smaller line. Thermostat Inlet Hose

 

[GlenM]

Line 3.it is the smaller line. Thermostat Inlet Hose

Interesting ! Both line 1 and line 3 have goodly rust at the thermostat ports,
wet but not plugged up..

Assumption:
Stuck thermostat, never opened during repeated flushings.

Going to introduce flush mixture in both line ports, maybe let sit for a while, then run entire flush once again. Maybe spray WD-40 into ports, don’t think CLR would be best idea.

 

[scos53]

I spent 50 bucks on a thermostat I didn't need. Take it out and test it first. I would take the Water Pump cover off and check the pump impellor to make sure it is working .IE the impellor is connected to the shaft.

 

[Itinifni97]

Wow, I just looked up the thermostat, must be made of titanium or something. I agree with scos53, take it out and test it first.
I think the OP asked about the pump location in another post, don't know if he ever checked it though. I'm with you on that being the next thing to check if the thermostat is ok.

 

[GlenM]

Wow, I just looked up the thermostat, must be made of titanium or something. I agree with scos53, take it out and test it first.
I think the OP asked about the pump location in another post, don't know if he ever checked it though. I'm with you on that being the next thing to check if the thermostat is ok.

With thermostat suspended in a sauce pan, when through repeated cycles of near boiling/cold water tests. Thermostat opened and closed. Didn’t have thermometer, but I’m gonna go with the open/close.

It looked brand new when I removed it, should since it only has 2500 miles on it, although 15 yrs old.

Anyone know of a video or narrative on what steps to take to get to water pump ??
Thanks!!