'86 1100 overheating

[mville656]

I just bought a 1986 VT1100C. I haven't had a alot of ride time on it yet, but I've noticed that when I ride in the warm weather(above 60*) it tends to read HOT on the temp gauge. I don't have a repair book for it YET, but will be getting one soon. If anyone has any ideas in the mean time, let me know. I've never had a watercooled bike before so I'm kind of in the dark.


Thanks,
Mike

[cowboy]

Make sure the radiator is clean.You can get alot of dirt and bugs in the cooling fins that will block the airflow.Also you might need to flush the cooling system and make sure you have the right water/antifreeze mixture.

[amazngrace]

I've got the same bike and mine tends to run pretty
cool, generally she does not get to half hot until at
least 20 miles go by, and rarely goes past half while moving.

What Cowboy said is a good starting point. After that,
water pump.

Does the cooling fan come on?
Overheat while moving or just sitting?

...ED

[amazngrace]

Oh, by the way, welcome to the forum and:


FUCK OFF NOOB !!!

...ED

[98 ShadowT]

I have a 98 1100 and my hot light went on due to the fan being stuck and blowing my fan fuse. I replaced my fuse got the fan to work again and . Not to say the fan won't get stuck again, but a thing to watch for.....

[mville656]

Thanks for the welcome. I've been riding since I was about 8 and have accumulated several (8) bikes.(all old but fairly good) I got this one about 1 month ago. I changed the antifreeze in it today and cleaned out the radiator. Neither helped although I did some more checking. It overheats at least while idling or driving slow. The electric fan did not come on the entire time it was running today and the temp gauge read HOT(just under the red) when I shut it off. I'm sure the coolant level is OK. I think it may be the fan, it isn't stuck but does not run. How is the fan turned on, there has to be a switch, but where is it? I saw one on the bottom right side of the radiator, is that it. Is there a thermostat?

I am glad to find a place like this so everyone can share experiences and info.


Thanks again,
Mike

[amazngrace]

What did you use for antifreeze?
For the Honda engine, you must NOT USE
antifreeze with silicates in it.
Check the bottle you used, if it isn't 100%
silicate free, DO NOT RUN THE BIKE.
will explain after dinner.

...ED

[amazngrace]

OK any antifreeze with silicates will tear up the
water pump in short order, and the first instruction
for replacing the water pump is:
"remove the engine from the frame"

The thermostat is under the coolant filler neck
under the right steering neck cover.

the fan swithch is on the radiator.

If your guage is making it that high, your fan
should be coming on!

...ED

[amazngrace]

Fan thermoswitch check:
pull the wire,
jump the pins,
turn ignition switch on, fan should run.

if not- fan or fan wiring problem, no fan relay
to deal with on this baby !
If fan runs, bad thermoswitch, you can further
check the switch by checking the resistance across
the pins on the switch:
Engine cold = open
Engine hot = closed


But before all that, check the 10 amp fan fuse !!!


...ED

[amazngrace]

Of course it could be a temp guage problem,
but that is fairly rare.

...ED

[fegs]

check the most commun things. First, is the fan working? If it is and still getting hot, you might have to look further than your radiator (cylinder head issues), is the oil milky? Go to the head for by pass. If not, drain and clean your rad, check for thermostat (if any, it could use a temp sensor).... Get a rad thermometer, check it against the light.

[Machinehead]

You'll have to verify that the cooling fan is operational. To do this you'll have to remove the wire connected to the thermoswitch located on the lower right side of the radiator and ground it. With key ON fan should operate.

Results?

[mville656]

Looks like it is the switch for the fan. I hot wired the fan to run and rode for about 2.5 hours today and didn't have any problems. Looks like I need a new switch.


Thanks to all,
Mike

[amazngrace]

Machinehead had it right on the thermoswitch,
one wire only , it provides ground for the fan
when hot.
I was off on that one!

...ED

[Machinehead]

Looks like it is the switch for the fan. I hot wired the fan to run and rode for about 2.5 hours today and didn't have any problems. Looks like I need a new switch. Thanks to all,
Mike



I really hope the thermoswitch is the fix, but you'll have to note that you did have the fan running all of the time and this could rule out other possibilities.

To rule out the thermoswitch there're test performed on your baby's stove using a meter to actually verify it is bad.

What I am saying is.....having the cooling fan running full time may prevent what could possibly be the source from rearing it's ugly head.

There is a procedure to test the thermoswitch. k?

[mville656]

I put the toggle switch in just to see if it would over heat and to buy me some time until the new thermoswitch gets here. I only had to run it when I rode through town or at slow speed. I shut it off when I was going road speed. Now if we could get some more nice weather I can get out and ride it. I had a month off of work and only got to ride about 70 miles. I am off again this week and the weather man says rain everyday. Well I guess that's what you get living Illinois.

Thanks,
Mike

[GDI]

Hey mville656,

I've got an '86 VT1100--just bought it last year around this time. Mine runs real cool. It's never been up to "hot" on the gauge, and I've never heard the fan come on either. . . . I pulled the wire off the thermoswitch and ground it out and I know the fan works, so I decided to change the thermoswitch this winter. The fan still hasn't come on!


Just thought I'd post as this is something that I'm watching on my bike, and my experience sounds a lot like what Ed posted.

GDI

[amazngrace]

Only time mine ever got warm enough so that the fan
came on is when I left it idle for 10 minutes, even then the guage was only up between 2/3 and 3/4.
But then I've only had her since October.


...ED

[frank d]

Yes My 86 1100 overheats as well. I jumped the two wires going to the fan from the guage on the tank and nothing. I then used a 9 volt battery connected the pos. to the wire attached to the "switch" at the base of the radiator and the neg. to the 2 wires that I jumped and the fan worked.

To me this sounds like a bad guage???

I have used non honda antifreeze before and i do not know if it was ____ free.

I think the fan not coming on is causing the problem is the "switch" in the guage or is in the part at the bottom of the radiator?