Cooling System - Is it worth checking the thermostat?

[Grumpy]

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Has anyone checked or replaced their water thermostat? Is this something to leave alone unless there is absolutely positutely a problem with cooling or maybe not a bad idea to look at every 40k miles or every 6 years or so?
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When I'm riding with other Voyagers my '03 XII seems to run 'a mark' hotter than theirs. And my Mrs & I are riding from Ohio to the rally in SantaFe in July.. So among other maintenance I'm doing a 'flush & fill', checking wires & hoses, and wondered about checking the thermostat.
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The shop manual has the specs- and there is a temp & a 'wide open" spec. I pulled the battery & looked at what I'm up against.... Ah Shucks! Dagnabit.. It looks like a lot of work .... I believe I'd have to pull the left faring, then remove a ignition coil.... is this worth it? I'm running about 1 "mark" hotter than other Voyagers I've ridden with. And in city driving at stops/traffic lights in just 80 deg. weather the fan will come on regularly. I only have 42K miles on it, and change the antifreeze yearly since '05 when I bought it (second owner).

[Furchin]

Grumpy, if you are even a little concerned about the temp I would for dung and giggles replace the radiator cap and see if this brings the temperature down a mark or two on the gauge. For around $8.00 this may soothe your mind.

[Rhinestone Kawboy]

You might also want to be sure that you are not running with too much antifreeze to water ratio. I now use a 50/50 mix right out of the jug as I believe I was running with too much before- you know,you put just a little more antifreeze to make sure. But, that just a little more can actually reduce the cooling effect. Water cools, antifreeze does not. When I went to all pre-diluted antifreeze, I would say my gauge dropped about one mark, so I guess I had too much antifreeze to water ratio.

[Grumpy]

thank you both. I hadn't thought of the radiator cap, I'm going to replace it, like you said - $8 - not a big deal, and not something I'd think about wearing out, even a little. Are those caps available at a regular auto-parts store?

Regarding the mixture % - I agree, and maybe it did get a little more antifreeze in it when I topped it up. But about the 50/50 mixture... doesn't Kaw recommend 46%/54% or something picky like that (I don't have the manual in front of me, but recall it wasn't 50/50) ??

[Rhinestone Kawboy]

Regarding the mixture % - I agree, and maybe it did get a little more antifreeze in it when I topped it up. But about the 50/50 mixture... doesn't Kaw recommend 46%/54% or something picky like that (I don't have the manual in front of me, but recall it wasn't 50/50) ??

Your right Kaw mentions a 57% soft water to 43% coolant in the service manual. But I've had 0 problems with running the 50/50, and so far I've run it in temps from 117 degrees F to 35 degrees F. Probably in extreme heat, the 57 to 43 ratio would be slightly better as water does cool more than antifreeze, but for what I've been in so far, the 50/50 does just fine, and you can get that pre-diluted.

[Grumpy]

Has anyone tried adding some 'Water Wetter' to the mix?? I know the product sez it works best in straight water, but also that it can be added to an antifreeze mix...

[Steve in Sunny Fla]

the water wetter type products are very effective. They are surfactants that break the surface tension of water, and allow the water to cool without creating nucleat boiling hot spots, particularly in the head. Water wetters work best with a very low amount or no antifreeze. Of course the boiling point is lowered, but the coolant becomes so much more efficient at heat transfer that overheating isn't an issue. A word of caution though, the reduction of anti-freeze can leave the engine unprotected from freeing during the winter, so it's best to run about 15 - 20% antifreeze if you're going to leave the concoction in during the winter. HTH, Steve

[Furchin]

Grumpy, try the stant brand radiator cap, Part # 10227. That is the one I used to replace mine. Most auto parts stores should carry this or can get one for you.

[Grumpy]

Thanks again everyone. Today I'll be out looking for that Stant radiator cap.
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I have tried Water Wetter, but am too.. 'chicken' ... to reduce the amount of antifreeze too much. In many posts on changing antifreeze frequently, I've accepted that the anti-corrosion & water pump lubricating properties are equally important to long engine life. I use only a little less antifreeze to water than the manual recommends (40%/ 60%) and do add water wetter.

[Grumpy]

Grumpy, try the stant brand radiator cap, Part # 10227. That is the one I used to replace mine. Most auto parts stores should carry this or can get one for you.

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Would you let me re-visit this? ... I was getting ready to go to the store, but first looked up that radiator cap on the internet so I'd know if there were substitutes... and found it's a 13lb cap. The cap on my XII is marked "1.1" - and a conversion chart on the internet sez that 1.1 (kg/cm2) converts to just about a 15lb cap. So since the factory cap is a15lb cap, would going to a lower pressure cap - 13 lbs. help, or should I look for another 15 lb cap? Or ????
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As it would happen, a local Kaw dealer has a Kaw 1.1 cap - "only $28" before taxes! - The Stant is less than $10 here.

[Chris near Kansas City]

Per the '86 shop manual I have here at work (don't have the supplement handy), the rated cap pressure should be between 11 and 15 lbs, or to quote the book, "....must open at the specified relief pressure."

[Grumpy]

Thanks again... I have to laugh at myself more and more often... The more I reads the more confused-er I can become!

[Grumpy]

Final outcome I'm repeating here from my post on changing the antifreeze- after trying the NAPA version of the STANT cap - after just 20 minutes of riding, I pulled over and noticed a pool of coolant quickly forming under the bike. headed home post haste..
long story short - replaced it with the original cap, and all, somehow (the Motorcycle Angels?) seems fine, no leaks noted, smelled or seen, And I've gotten it much hotter since. I'm staying with the Kaw cap. :)

[TaiwanJohn]

Have your radiator flushed. It happened to me last year. The bike stayed cool about 90% of the time, but when it was hot out, the bike got waaay hot. The radiator was about 75% clogged.

I had the radiator cooked out and pressure tested, and no more problems. Mine was really clogged so it cost more, about $150. But that was cheaper than a new radiator.

If you are having problems in 80 degree weather, I would bet it's your radiator.

[Grumpy]

Thanks t-john, I'll keep that in mind for the coming year. Shucks, this is only an '03 with just under 45K miles on it... I bought it in '05, am the second owner, and have changed the coolant yearly (use Prestone green for aluminum, no silicates), I can't imagine the radiator being even partially clogged. But I've also learned that surprises happen!

[TaiwanJohn]

The corrosion doesn't happen because of mileage. My radiator guy told me it was mainly caused by electrolysis. The different metals in the cooling system cause an electrical current, aluminum engine, steel water pipes, and brass in the thermostat.

[Leonard Russ]

I was lucky enough that a radiator hose burst just as I was pulling into my drive a few years ago. Well I figured I was foolish for not changing out those old '86 hoses sooner.

Then two years ago after I had changed out ALL the hoses, the Voyager started leaking JUST THE DAY BEFORE THE 07 RALLY!!
the leak was right at the neck of the radiator cap. When I later got around to checking things out, I decided to see if my overflow hose was clear. BEHOLD ! I found the overflow hose jammed between the frame and the fuel pump. So the main hoses were running under too much pressure(And the burp tank never was showing changing fluid levels.)

A quick check to be sure the hose is clear is to run a clothes hanger wire through the hose.

Leonard in Colorado

[Grumpy]

Alls well that ends well :)
back home this week from SantaFe - ran great. No trouble with the 105 deg + heat wave in Oklahoma, (with my riding buddy pushing me to run at 80 mph + + at times , a tad over 4k rpm). So, given that, I'm tickled. No overheating, no loss of coolant, and the fan came on & shut off as needed. Thanks all for the help & hints.