changing coolant

Bird, how many miles are on the bike?

Is it LOW, or just a bit below the low level in the coolant overflow bottle? These bikes tend to like to be a bit below the low level mark on the bottle. Any higher and you will overflow coolant after a good ride.

If you need to fill it, you can buy a bit of distilled or deionized water at many grocery stores. Tap water has minerals and chlorine that will attack the walls of the coolant passages and the radiator over time.

As far as brand my dealer recommends the Prestone stuff. Yellow bottle, says safe to mix with any coolant, coolant is more yellow than green color.

Devious2xs said:

Is it LOW, or just a bit below the low level in the coolant overflow bottle? These bikes tend to like to be a bit below the low level mark on the bottle. Any higher and you will overflow coolant after a good ride.

Click to expand...

+1 Anywhere much more than just above the "LOW" line on the overflow results in a puke of coolant after a ride. Not a big deal, but it's annoying when someone sees a puddle and compares it to a Harley. :violent1:

yeah... I don't even see any in the overflow bottle at all. I looked in the radiator itself and that is full but the overflow bottle is on empty. got it back from the dealer wednesday after a rebuild and didn't think to check it. Ran it hard yesterday and only got to the fan temp. point maybe 3 times. But never went above 104 degrees C. I looked in there today before a big ride and sure enough... empty. Could I have damaged the bike from that ride yesterday?

Devious... should I add plain water or should I go to cycle gear and get some watter wetter or engine ice?

First off, I'm sure you have done no damage if it didn't overheat. Your best off with the recommended 50/50 mix of coolant and distilled water although 100% distilled water is OK too. I think (but not sure 'cuz I've never used the stuff) that you have to drain the coolant and and replace it if you want to use engine ice. Just fill the reservoir a little past the min point. It will puke out anything beyond that.

Just try water to start. If you have some "Soft Soap" in the house, you can add 2-3 drops to reduce the coolant surface tension - it works the same as the surfactants in Water Wetter. Let's try to find out how hot the engine regularly runs before you add Water Wetter or convert the coolant to Engine Ice.

More than likely, the block had some air pockets in it when they filled the engine with coolant. After a couple of heat cycles, the air pockets filled with water. It will likely do this a much smaller amount when you fill it again, get it warm and let it cool. Then check the level again.

How low is the level in the radiator? You likely did not hurt anything, unless the level was pretty low, then the thermostat would only register a bit above the boiling point - right around 104* C.

thanks all for the replies. Good information!

Devious, the coolant is just below the lip when I open the radiator cap. Do I add the water in there or just put it into the overflow. A friend and I are going for a ride today and I am wondering if I should leave it be and see if it expands into the overflow tank or if I should add water now to be safe. Any suggestions?

Also, btw... the bike's fan generally comes on at 104 (sometimes 105C) I have never seen it go above that. Yesterday it was running at a consistent 79-82 C for close to 250 miles.

Jut add to the overflow bottle and ride it. If you add it to the middle of the level markers ont he bottle, you will have enough to fill the lines, but it will 'puke' a few times until it is happy with the level.

That level didn't hurt a thing.
As long as the level is above the outlet on the radiator, the temp on the gauge is accurate. If it gets lower, the temp sensor will only read the temp of the steam - even though the block will get hotter.

Just for random knowledge, you can expect performance to drop off above 225* F (107* C), and aluminum blocks tend to have issues above 250* F (121* C). Warpage tends to start occuring at 280* F (137* C).

Oil temp can alter these numbers.

Tks Devious! You rock!