83 Venture overheating Help

[Guest stewlloydw]

My 1983 venture overheats and I cant find out why.

I have replaced the thermostat, water pump and the radiator cap.

The fan comes on and runs the correct rotation and at the right temp.

No mater what I do it I cant find out what is causing this and I have taken in to the repair shop and they don't know why it is doing this either.

I let the bike sit for about five years but when I decided to ride it again I took it into the shop and had the carbs serviced and what ever else it needed.

Hope someone can help me out with something elese to try

[utadventure]

Check the hoses!! I've had a hose bubble on the inside and restrict the water flow causing the vehicle to overheat.

[Guest stewlloydw]

Thanks for the reply I will check them

Which hose was it top or bottom?

Did you pull the radiator in order to replace the hose

[Tommy]

I just replaced the upper front cylinder hose, found it had collapsed and was restricting coolant flow...Now Bertha runs soooo cool...

[Grandpa]

Is it truly overheating or is the gauge giving you an incorrect reading?

[Guest stewlloydw]

Yes it is overheating when I turn it off after the temp gets to the red zone it sits there and boils and gurggles. Also the fan kicks in when it gets to the red zone and that is a different temp. sensor

[Gearhead]

Have you thoroughly flushed the cooling system? Remove the lower radiator hose at one end and the cylinder side covers and little rubber plugs behind them, along with drain and rad cap. Flush water with a hose in one and and out the other, then reverse, in every combination you can think of. See what comes out. Could be that the radiator needs servicing. There's also some funny things that go in in the "breather box" - the aluminum hot-dog-looking thing between the cylinders under the carbs.

 

Jeremy

[BradT]

Is the water flowing or is there a possible problem with the water pump.

 

You could take rad cap off (engine cold) and then let it run. When the thermo stat opens you should see the water flowing in the rad.

 

Best of luck

 

Brad

[hipshot]

might also check the "thermal switch" , i think it is called.

it might be that the fan is coming on "after" the engine has already gotten hot, and then cannot supply enough circulation to cool the engine down , before "boil-over".

just jt

[Marcarl]

My first guess would be a collapsed hose.

[Venturous Randy]

Another area of concern is the metal tube across the front of the engine. I have heard several state having a problem with it getting stopped up. Another thing to do is turn the hex knob 180 degrees and you should see water flowing thru the radiator even with the engine being cool.

RandyA

[Dano]

Just throwing it out here, mine ran hot all the time till I serviced my carbs and got them synched up, could be as simple as that.

JMO, Dan

[Toy3zve]

Recently I put some "Water Wetter" (WW) in the overflow bottle (it calls for one ounce of WW per quart of coolant capacity, so I think I added 6 ozs to the overflow bottle).

 

The next day I rode to work and immediately noticed that instead of the temp. needle going from 1/2 to 3/4 of the gauge, it remained between 1/3 and 1/2. After work I took a ride up into the mountains, where the temp. would range from 3/4 to right below the red zone on the gauge, but now it wouldn't go above 2/3 max.

 

Put some in my truck too and it lowered the temp. about 20 degrees.

 

Great stuff. Get some.

[Neil86]

In order for the thermostat to work properly on a 1st gen you need the flow through the metal tube mentioned. Keep in mind the t stat is after the radiator on a 1st gen. The bypass (metal tube)flows directly from inlet (top) of rad to the t stat (below it) and then to the water pump, so the t stat is getting flow and can monitor and control the temperature. If its too hot...it opens allowing colder coolant from the rad to mix going to the water pump. In order to drain the radiator there is a drain valve which opens from the bottom of the rad to this bypass line so you can drain the rad when the t stat is closed. When the drain valve is ON it blocks the bypass from inlet(top) side of rad and opens to the bottom of the rad to allow draining. When the drain valve is in the OFF position it blocks the drain from rad and opens the bypass from top of rad.

So....if you leave the drain in the ON position you get colder coolant (from the bottom of the rad) flowing under T stat which tends to keep it closed. If the drain is in the OFF position (as it should be) and the tube is plugged....the only flow through the T stat is the tiny bleed hole on the T stat itself, plus the water pump has virtually no supply. Both issues will cause overheating.

[zagger]

Maybe you already have this fixed by now but . . . early models like yours (and mine) have a plastic water pump rotor and the later ones have aluminum. I understand that sometimes the plastic blades erode and effectively stop pumping. I replaced mine with an aluminum one. Just a thought.

zag

[GeorgeS]

You said you rebuilt the water pump, so your impeller is OK.

 

All the above reply's are good info, however Due to Age, I think I would Remove and replace " All " of the hose's. Go to the IPC and order all of them. Dureing the replacement process you will probably find a blockage someplace.

 

Also, Consider that there might be a lot of Crorrosion " INSIDE " of the Radiator, !!! Take it to to a professional radiator rebuild person, and have it checked out. But if its plugged up, I would suspect you might need a new radiator.

You might not be getting enough flow capacity thru the radiator.

[Poledar]

My 1983 venture overheats and I cant find out why.I have replaced the thermostat, water pump and the radiator cap. The fan comes on and runs the correct rotation and at the right temp. No mater what I do it I cant find out what is causing this and I have taken in to the repair shop and they don't know why it is doing this either. I let the bike sit for about five years but when I decided to ride it again I took it into the shop and had the carbs serviced and what ever else it needed.Hope someone can help me out with something elese to try

 

First off, shame on you for letting it sit for 5 years. No doubt it got lonely and is punishing you! Alternatively, check the temperature gauge itself. Flush the block and be sure of full emptying of old fluids and no blockages. Beyond that, I am no mechanic, but what do you have to lose?

[MasterGuns]

OK, I am really curious; did you ever figure it out?

 

 

 

[Guest stewlloydw]

As of yet the answer is no. I ordered new hoses but have not installed them yet. This is no small job to install these hoses. I was out working on the hose installation today but I wasn't able to get the part where all of the hoses attach to out into the open. It almost looks like I need to pull the Faring off to get to the device where the hoses connect. Pulling the fairing off is not an option right now. I did start removing the radiator and disconnection the uper hoses but stoped after I still couldn't see the the hose manafold inorder to remove the old hoses. Any help on how to do this would be wonderful.

[cowpuc]

I have yet to get to this point on one of my Ventures but here is a whole new thought.. On lots of other watercooled stuff I have worked on there are air bleeder locations - located in areas that cant purge themselves.. If these areas are not purged they will create hot spots and do exactly what you are describing.. I do not know if our bikes have an air bleed to get fluid into areas like this BUT it would be something I would look into if I were in your shoes..

Also,, if your carbs were not torn down and the jets physcially cleaned with a jet wire - not just sprayed off with carb cleaner - there is a good chance you are running lean - this WILL make an engine run REAL hot!! Also,, any air/vacumm leaks can also do this..

[GeorgeS]

You will have to remove the lower fairings on each side for hose replacement.

 

Also, you need to pull out the "Heat Baffels " One over the fwd cylinders, and one over the rear cylinders.

 

Have you found the Diagram on page 4-1 of the service manual.

This " Flow chart " might help you .

 

Don't forget to take your radiator, to a radiator specilist and have it checked. Untill you know that its Flow Rate is good, you will be beating your head against the wall.

 

If that radiator was crudy before it was parked for 5 years, you are probably going to need a different radiator.

[Gearhead]

"You will have to remove the lower fairings on each side for hose replacement. "

 

 

 

And, by the way, this is not a hard job. Upper fairing may be a different story, but lowers are easy.

 

Jeremy