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Is there a way to empirically prove that a thermostat is fully open and the water pump is at design flow when a bike is at an elevated temperature? If not could Mr Harmon please please provide the videos for getting to the thermostat? I've got a couple of bikes to film on.:confused:
 
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Not while the thermostat is in the bike. Normal thermostat testing involves removing it and suspending it in a beaker of water then measuring the opening as you increase the water temperature. Of course, this is much easier in a car because the thermostat is generally more accessible.
 

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I show how to remove the top shelter, and fuel tank and drain the coolant. This should give you a good head start.

The thermostat is under the water pump cover, next to that starter. Once you have the fuel tank out and the coolant drained, remove the three hoses, and five bolts on the water pump cover and you are there.

The manual tells you to remove the starter motor and alternator, but from what I can see, it looks like you can remove the cover with them still in place, and the manual shows a photo of the cover removed with a starter and alternator still installed.

Just curious, what makes you think the thermostats are bad in two bikes?
 

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By the way, if your thermostat isn't opening up, you will know it pretty quickly, as the radiators will boil over and fill the overflow tank and spill out coolant, and the engine will overheat.

I'm not sure how you could tell if a thermostat was stuck full open. It might make the temp gauge slow to warm up on a cold day. I believe the normal failure mode for a thermostat is for it to stick open, though I have seen them stick closed. You'll usually know it pretty fast if it is stuck closed.

The only other scenario I can envision is a thermostat that opens, but does not open fully. I suppose that one might be a bit tougher to diagnose, but the results would probably also lead to a boil over, depending on how far it opens.

Back in the old days, folks in the south used to remove the thermostats and run cars without them, claiming it increased the flow rates and cooled the engine better. The problem with this is that the thermostat is intended to keep the heads at a fairly constant temp for proper combustion. Running it wide open would probably lead to reduced gas mileage and possibly carbon build up inside the combustion chamber. Not to mention decreased gas mileage, increase emissions, and increased wear. Modern FI engines are designed to run within a pretty tight temperature range, and it's the thermostats job to keep it in bounds. Catalytic converters also operate in a pretty tight temperature range, and the thermostat helps insure that as well.

As for how to test flow rates to see if it is working right, I really don't have a good answer for you short or removing it and doing the hot water test outlined in the manual. To try to do a flow test, you would need more equipment than the average guy would have in his garage.

The standard practice in autos has been just to replace the thermostat any time it was in question, and some shops will tell you just to put in a new one every three years or so as a preventative measure. However, I don't think I have heard of a single problem with the thermostat on the GL1800 that I can remember, even on extremely high mileage bikes. And I haven't seen as many failures on my own car thermostats as I used to either. I could be wrong, but its my general feeling that thermostats have become more reliable.
 

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Empirically proving

Schnidly, "Empirically proving" As a suggestion, try proving

the tempeture gage is accurate. To empirically prove that the bike

is NOT HOT OR OVER HEATING --extend the overflow line -- at the

coolant fill cap (PRESSURE CAP) -- to a visible lacation.

If she starts to blow steam and coolent then there is a problem.

You can trust water but you cannot trust gages.
 

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I "think" all automotive thermostats are now "fail safe" (that is they are open if broken). That was not always the case back in the 70's and before. Before anti-smog devices were so common, it was not such a big deal to remove the thermostat and run wide open. I can not recall any problems folks had doing that, but it was typically hot rodders who were doing what could be done to fight boil-over anyway -- in winter they would put card board in front of the radiator to get enough heat to keep the engine temp up to normal. With all of the heat sensor stuff in modern autos and cycles, it could screw-up the deal to run without the thermo.

If the bikes warm-up very quickly upon starting as is typical of GL1800 (my temp gague or thermometer is at the sweet spot within two miles of riding post start-up); then the thermo is closed at cold conditoin. If the thermometer rises to the sweet spot and stays there under normal riding conditons, then the thermostat is probably functional. If it rises over mid-way with only minor stress and then sinks to sweet spot again when you baby it (considering all else is normal) then you mmay have a restricion.

I have heard reports of bad radiator caps and that can mimick the restiction symptoms as the coolant then boils at a low temp and steam is a lousy coolant. I have noticed Honda's service bulliten RE possible corrosion restriciton in '01 and some '02 bikes and that could lead to a restiction by now. I have read Stu Oltman's excellent Wing World articles describing really congested GL1800 cooling systems which I suppose was due to neglect or use of hard water and such. But failed water pump volutes? No. Failed thermostats, remarkably, I can not recall even one yet. Failed water pump drive shaft seals, I can recall a few posts on that on this board.

I would start with a good pressure flush and fresh approved coolant before trying to diagnose further. Let us know what you finally find.

prs
 

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Empirically proving

Schnidly, Because the coolant recovery system is "so efficent"

coolent will be in the neck of the expansion chamber and

thus will spit "some" coolent as the temperture rises to normal.

Hoping you can ride and enjoy this wonderful machine. :shock:
 

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Primary test has been described. Quick warm up, no boil over and normal running temps.

The rest requires work. The wing runs just a little cool - 90°C 194°F
 

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Discussion Starter #10
I show how to remove the top shelter, and fuel tank and drain the coolant. This should give you a good head start.

The thermostat is under the water pump cover, next to that starter. Once you have the fuel tank out and the coolant drained, remove the three hoses, and five bolts on the water pump cover and you are there.

The manual tells you to remove the starter motor and alternator, but from what I can see, it looks like you can remove the cover with them still in place, and the manual shows a photo of the cover removed with a starter and alternator still installed.

Just curious, what makes you think the thermostats are bad in two bikes?
First off I would like to thank you for your very entertaining dvds. I know that the thermostats close and modulate. I do not know if they open fully. If they do not open fully then obviously we are not getting the full heat transfer capability of our systems.
Seems most of the trike owners on this forum claim they can pull trailers in hot weather and not even have their coolant temperature increase above normal. Well I’m getting tired of not being able to do legal speeds on flat roads on hot days without above normal conditions. In the Jan 2008 issue of Wing World, Senior Technical Editor Stu Oltman has an excellent article concerning overheating on two Goldwings that was resolved with what he called a “coolant pulsator” I have used these in industrial applications to clean condenser tubes so I borrowed one. I followed the Honda TSB on overheating and his article to the letter except for pulling the thermostat and checking the cylinder head coolant capacity (as her vin number did not apply). I found absolutely no suspect conditions. Whenever her trike pulling a trailer gets hot my two wheel soon follows. If mine pegs just how much hotter is hers getting? We try to get out of those situations as soon as possible but sometimes safety does not allow a timely road exit. So I’ve come to the conclusion we have no problem or the thermostats are not opening fully.
 

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By normal highway speeds, do you mean speeds above 25mph? The typical GL1800 gripe about overheating is relative to speeds at or just below 20mph. Above 20, the faster you go, the better the cooling system should work, even in excess of 70mph. By your description, I wonder if your rads have air pockets. Go for a nice relaxing ride to thoroughly warm the bikes to normal operation temps and let them cool to room temp of the center stands for the 2 wheeler and as usual for the trike. Then check the left radiator by removing the radiator cap. It should be full to the pressure relief orifice in the filler neck. If not, the recovery plumbing is letting air into the rads. If its full, have the caps tested. Very odd for one fellow to have the problem on two GL18s when they have been serviced by schedule.

prs
 

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Pigeon Roost , Without a base line there can be no

meaningfull diagnosis.

Thermocouple-digital. Or boiling water. The ECM driven gage is

non-linear. And may be defictive.
 

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Discussion Starter #13
By normal highway speeds, do you mean speeds above 25mph? The typical GL1800 gripe about overheating is relative to speeds at or just below 20mph. Above 20, the faster you go, the better the cooling system should work, even in excess of 70mph. By your description, I wonder if your rads have air pockets. Go for a nice relaxing ride to thoroughly warm the bikes to normal operation temps and let them cool to room temp of the center stands for the 2 wheeler and as usual for the trike. Then check the left radiator by removing the radiator cap. It should be full to the pressure relief orifice in the filler neck. If not, the recovery plumbing is letting air into the rads. If its full, have the caps tested. Very odd for one fellow to have the problem on two GL18s when they have been serviced by schedule.

prs
Both bikes were bought used, the 2 wheel a 01 the trike a 03 both bikes were is show room condition and very low mileage. I am aware of their histories and they were well maintained. Several months after puchase I changed the antifreeze to be absolutely sure and began diagnostic checking within my ability (ie I did not remove the thermostat). I can assue you there are no airpockets and both radiators are full. There is no debris on the outside of the radiators, no visible deposits observed from the inlet and outlet openings, all fans operate per design. Both bikes cannot maintain normal temperatures at ambient temperatures over 100 degrees at 70mph on flat ground. I verify the right hand radiator is completely full all the time by taking the cap off. I get the same gas mileage as others in our riding group on the same day and the trike gets slightly less. I did not check the coolant volume in the heads as both bikes were not in the vin range of problem bikes. I have not had the caps pressure tested but have never had to add fluid. Would not a weak cap cause loss of coolant from the system when the expansion tank overflowed?
 

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schnidly,

More info is good. If this were mine I would tap into the fan's wires to

install two lights. Just maybe the fans are coming on when the

coolent reaches the point where they would; if not moving.

And install a known thermometer on a hose leaving the block. :shrug:
 

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schnidly, Did both bikes come from (ONE) PO ? Or have a mechinic

in common? :shrug: Might try a third bike. :rolleyes:
 

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overheating

Schnidly,
Since this is happening to two different Wings under the same conditions, have you considered the grade of gasoline or the brand? With very high temperatures or too low of octane fuel, you may be experiencing some detonation which can lead to overheating. Try going up a grade (from regular to plus). A bad sensor could also be the problem but less likely since two bikes are involved.
Safe riding.

Rick
 

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Yes, full rads with proper reserve in recovery tank when cool would over-flow if cap were weak enough to allow boil-over. Your descriptoin sure sounds like "clogged arteries", let us know what you eventually find.

prs
 

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Don't know what year wing you have but on the 01's, a properly operating thermostat is supposed to start opening at 169 to 176 degrees, F and be fully open at 194 degrees, F.

On a warm summer day, the coolant temp more than likely will be at least 194 degrees F or higher and the thermostat if properly operating should be fully open.
 

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Discussion Starter #20
schnidly,

More info is good. If this were mine I would tap into the fan's wires to

install two lights. Just maybe the fans are coming on when the

coolent reaches the point where they would; if not moving.

And install a known thermometer on a hose leaving the block. :shrug:
Excellent idea, don't know for a fact that I would know the fan is running when the bike is above that shutoff speed.
 
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