Radiator Coolant Level

[AUS_TR650]

I was wondering if the level in the radiator is suppose to be full when checked when the engine is cold? With my radiator, I can see the tubes and when I lean the bike off its stand, coolant from the overflow tank fills it to the top of the filler neck. When the hoses are squeezed, the level rises indicating they're full of coolant.

Just wondering if the vacuum valve in the cap is not unseating to allow coolant to transfer when it cools down. It has quite a lot of tension on it in comparison to my car cap. I thought that if it is a recovery system, it should always be full. Like my car & the KLX (and that o/flow tank is at the rear of the bike!) Cheers

 

[Tinken]

Generally, it is supposed to be the thickness of your index finger above the top coils.

 

[Coffee]

I found this in the owners manual, beyond that, I cannot really comment:

 

[Tinken]

This model seems like it has a lot of cooling issues. You could switch to waterless coolant and there wouldn't be anymore overflow, gas pocket or over boiling issues anymore.

 

[AUS_TR650]

That's the overflow tank. The radiator cap is on the other side.

 

[blaine.hale]

Check on the side stand or while the bike is straight up?

 

[AUS_TR650]

Cap is u/s. Swapped with my klx and it is full when cold. Hoses are also firmer when squeezed at operating temp (old cap not holding pressure).

 

[Mark Regier]

Cap is u/s. Swapped with my klx and it is full when cold. Hoses are also firmer when squeezed at operating temp (old cap not holding pressure).

What is u/s?

Glad you started this thread. My overflow tank has (burped or leaked) a couple of drops of coolant every time I ride the bike then park it. I also find the coolant in the radiator neck to be lower than I'd prefer. But again, stand the bike up, and here it all comes... from the overflow tank I guess?

 

[R1D3R33]

I overfilled mine and for 3 week every time I ride, I have water blowing over the tank and down the side. Took turkey baster to remove excess fluid, but still drips after warm offroad trips or while I was out in Glamis.

 

[nev..]

What is u/s?

Unservicable / broken / buggered / stuffed

Glad you started this thread. My overflow tank has (burped or leaked) a couple of drops of coolant every time I ride the bike then park it. I also find the coolant in the radiator neck to be lower than I'd prefer. But again, stand the bike up, and here it all comes... from the overflow tank I guess?

Sounds like yours might be knackered too

 

[Navelgazer]

Unservicable / broken / buggered / stuffed


Sounds like yours might be knackered too

Had the same problem, bike was not getting hot, just decided to check the coolant, empty in the overflow tank. Topped up and next ride coolant all over the right side of the bike, my boot, jeez that stuff is slippery. I looked at the overflow pipe with the engine up to temp and where it joins the radiator they use a press fit hose clamp, from under this clamp it was just bubbling away. Fitted a screw clamp over the tail at the fattest part now all is fine. Not all that trusting of those press fit clamps. FYI

 

[Rick Rides]

I am overheating during normal riding. Stop engine light on, blinking temp bars. Coolant spurting out of res cap. Radiator seems not too hot. Thinking I am not getting flow, like the pump is not working. Just started last night. Any ideas?

 

[AUS_TR650]

1. Is the fan coming on although it shouldn't have to while riding?
2. Make sure engine & radiator are full when cold. Slowly add coolant & squeeze hoses to purge out any air.
3. Thermostat is cactus. If the other two are fine, take it back to the dealer. Could be a water pump issue like you mentioned. Good luck.

 

[blakebird]

I am overheating during normal riding. Stop engine light on, blinking temp bars. Coolant spurting out of res cap. Radiator seems not too hot. Thinking I am not getting flow, like the pump is not working. Just started last night. Any ideas?

My guess is an air pocket and you could burp it out....

I rode mine down to New Mexico for a weekend of riding with friends... on the ride back I did the last 200 miles on interstate at 75mph.
When I got about 40 miles from home I got off the interstate for a backroad route home, and stopped at a light. After a half a minute....water splashing on my left side caught my attention so checking the temp gauge I saw there were a few more bars lit.
Usually the bar under the 2nd digit (left of decimal) on the trip odo is as far to the right as I've seen. They were lit to the decimal point (maybe two more bars?)

I kept an eye on it and it crept a couple more to the right, but with still a couple unlit and no warning light or anything - I slowed down for a bit and it cooled back down to the first digit, but was still running hotter than normal and didn't look like it would get back to what I consider it's normal range.
When I got home I turned the hose on the radiator, popped the cap when it was cooler....and topped off the radiator and started the motor. It burped some air out - a noticeable amount, and I left it running and filled it until it was full, then buttoned it back up.

The temperature gauge had never really gotten past the halfway mark with the LCD's lit, but several hours of sustained high speed running saw it get a little warm after I got off the freeway and came to a stop with it idling.
Pretty comical when water spews from the catch tank cap....like a little fountain.

I've had other bikes that would do the same thing....get air entrained in the cooling system and need an occasional burp. Time will tell if it repeats this... but I suspect it's good to go after I saw air bubble out.

This weekend's riding added about 1500 miles and gave me a good feel for the bike on a road trip with a light camping load. Did great.

 

[Rick Rides]

Thanks for the feedback. I will try burping my baby first thing in the morning. Hopefully that will be that.

I will let you know the results.

 

[Rick Rides]

Thank you Blakebird. It worked! sitting on the second decimal as normal after your suggestions implemented this morning. Fan comes on, blows warm air and turns off after a few minutes... Perfect!​

 

[Coffee]

...When I got home I ...popped the cap when it was cooler....

When you opened the radiator cap, did the contents of the overflow tank empty - as it states in the manual?

 

[blakebird]

When you opened the radiator cap, did the contents of the overflow tank empty - as it states in the manual?

no, but that seemed strange to me when I saw that warning on the picture of the manual posted. Coolant is supposed to siphon back into the radiator from a catch tank as the system cools - it didn't seem like the level of the cap was low enough for any coolant in the catch tank to gravity over there....but I didn't really check closely. If it's set up to siphon, the hose end would be at the bottom of the catch tank....lower than the cap I'd think.

I did shine a flashlight into the radiator and you could not see the coolant level - so I grabbed my jug of distilled water and topped it off after starting the motor and letting air burp out.

 

[Next]

I was installing heated grips today and decided to check my coolant in the radiator. Fluid was quite low despite no overheating symptoms. I topped it up, and proceeded to burp it. A surprising amount of air was in the system, and I added a bit into the reservoir too to get it between the lines. I wish I had measured out the actual amount I added, but it might be worth 5 minutes of your time to check under the radiator cap.

 

[kjackbrown]

Cap is u/s. Swapped with my klx and it is full when cold. Hoses are also firmer when squeezed at operating temp (old cap not holding pressure).

From a KLX250 thread on Thumper Talk...

Just a little FYI. Our radiator caps can be found at any auto parts store.

Carquest part #33044
Napa part #7031406

The same cap is used on many, many different cars and trucks both foreign and domestic and has a 1.1bar (16psi) rating.