Overheating

[Relics]

Rode from St. Louis to Memphis and back. 1988 Voyager 1200 ran hot and boiled out of radiator on way down. Temp guage all the way in red and fan not on when we arrived. New fan switch installed 3 weeks before trip. Bypassed switch and put fan on toggle switch. Fan on at all times when coming home and guage still in red. Sprayed out of cap occasionally and I would stop for 15 to 30 minutes to let cool down. Never any fluid on ground. I run Engine Ice in radiator. I have had all hoses and thermostat and housing as well as radiator cap replaced. I am beginning to suspect water pump or radiator. Engine case feels normal. Overflow bottle always full. Not extremely hot. Bike starts normal when hot. Fluid is not extremely hot when spraying. Not a lot of steam. Just turned over 55,000 mile. Any help would be appreciated.

[gery]

It seems that there is no circulation of the coolant. Check the water pump.

[mountainman]

Pull your overflow tank and check to see if (over flow tube coming from radiator neck and going to over flow tank) is kinked or pinched shut during last tank removal. This is extremely easy to have happen and you don't realize its kinked closed during tank re-install. It causes the symptoms you described so its worth the a check.
Pull tank out slowly and try to look behind it as your removing. Often if you look at hose right after removal you can see where line had kink shut.
I truly hope this is your problem, its a cheap fix!
You could even remove radiator overflow hose at cap fill neck blow in it and see if its open all the way though to over flow tank.

[Relics]

I still need any suggestions for the overheating problem. Maybe Carl Leo or Ecap? Thank You!

[Me Again]

Fluid is not extremely hot when spraying.

This could easily mean the cap is either loose or defective .

[SgtSlag]

I think Gery is correct: the fluid doesn't seem to be moving. Localized heating, from coolant not circulating, will cause the coolant within the engine to super-heat, and turn into gas. The gas will force out the coolant at the weakest location, the relief valve. The coolant forced out, will be cooler, as it isn't exposed to much heat, just sitting beneath the cap. Best of luck. Cheers!

[JHD]

Relics states that the coolant sprays out the cap when his engine overheats. This is a closed system. Shouldn't the coolant if overheating be transferred to the overfill tank and if there is over pressure in the system come out through the hose connected to the tank and exit right in front of the rear wheel. Seems to me that if this is the case and he says that the tank is always full, which I take as coolant level at full mark, then there possibly is an obstruction or pinch on the hose from radiator to overfill tank or possibly the hose that exits the overfill tank. I think that is what I would check also.

[cushman eagle]

I have experienced this problem on farm tractors over my 45 years of being a part time mechanic.If the radiator has had hard water used in it long enough ,the tops of the tubes in the radiator can get sealed off to the point that very little water can get through, showing your symptoms.

[Relics]

How difficult is it to remove water pump? Are all Voyager 1200 water pumps the same? I have a parts bike but I'm a little reluctant to put used one on; but the parts bike only has 19,000 miles on it. Any help appreciated.

[triton28]

Relics;
it is pretty simple to R&R the pump once you have it exposed under the bevel gear cover. Try to have the hose clamps and the hoses, at the bottom of the radiator and the engine manifold, loose so you have room to manoeuver the steel pipes from the pump once you have removed the 6mm bolts holding them in. A swivel joint helps with their removal. Be careful not to nick the 2 o-rings on the pipes when removing them. I would replace them myself but if they are OK, check them carefully, one can re-use them. Use a soapy water solution, or a silicone based grease on the o-rings to reinstall the pipes. The important part is to make sure the engagement slot and tang are aligned before you try to tighten the bolts securing the pump to the crankcase.
Dave

[Relics]

Update: Installed new water pump and rubber gaskets and still have same problem. Temp red lines. Is it possible that the carbs are running too lean and causing this? This may be a stretch or maybe a dumb question, but I need help.

[Tonyvdb]

If it's running smooth after it's warmed up I would not think so? Could the rad be partially blocked not allowing enough air through?

[Mr Jensee]

Update: Installed new water pump and rubber gaskets and still have same problem. Temp red lines. Is it possible that the carbs are running too lean and causing this? This may be a stretch or maybe a dumb question, but I need help.

On a water cooled bike as a water cooled car, the leanness of the carbs will not cause overheating. You probably have a blockage somewhere, I suspect the radiator. Can you pull the radiator and insure you have fluid actually circulating through it?

[triton28]

Relics;
It would seem as though there is nothing left to cause the overheating except for a stuck thermostat, a blocked pipe, or the radiator itself. The thermostat can be removed from it's housing, cleaned, and checked for temperature of operation. Be careful not to nick the t'stat housing cover o-rings and generally they can be reused if in perfect condition. If the t'stat is found to be as per the service manual spec's, then I would have to agree it's probably the radiator. To be sure, you could reinstall the t'stat housing without the t'stat and if the problem persists, it's the rad. As noted, the cores have so small an opening on each vertical run that any amount of crud will block them in short order. The pipes and rubber hoses are comparatively large openings and generally don't block.
You can try a reverse flow from a garden hose if you have the rad off and it may help, but a chemical flush from a radiator shop might be the only way to unplug a bad rad.
Just some suggestions,
Dave

[crash33]

are you sure its really overheating and not a bad temp sensor?

[Relics]

I'm not sure at all. But it sprays out of radiator cap when hot. A moderate spray. Have replaced everything except radiator and I have a parts bike. The overflow tank is always full. Never loses any fluid and never low. I just don't know. I have spent a lot of money on this bike and I love it but it is getting frustrating. Carl Leo or Ecap can you help?

[mountainman]

Referring to my previous post! Have you checked your overflow hose that goes to catch tank to make sure its open and not kinked or plugged?

You can do this easy by removing hose at radiator fill neck and blow in it. if its open you will have air bubble sounds from catch tank!

Again if this hose is not open your cap will spew water as you described!

[metric]

You have air trap in the cooling system... that makes it overheat.

[Relics]

Have bled system. Checked for kink in overflow hose. The only thing I have not done is replace radiator. Have replaced ALL hoses; thermostat and water pump and fan switch. Its costing me too much money at the shop. Any help appreciated. Carl Leo?

[jre258 in SoDak]

Could it be that the thermostat was put in upside down? when I worked at an auto part store it happened even to experienced mechanics every once in a while. They would hurry to finish the job and do it wrong.
Jim