1984 vf500f cooling problems

My '84 gets hot pretty quick. I'm not too familiar with water cooled bikes. I noticed the radiator fan is not coming on, is it on a thermastat? and is there a thermastat for the water like in a car, which could be stuck? Where is the water pump? and there is a coolant leak somewhere and is dripping underneath the bike, are there any usual places for it to leak?

Thanks,
Jon

 

Always check you coolant level first. When the engine is cold refill radiator and overflow bottle to prevent engine corrosion use distilled water. If the coolant is low the fan will never come on and the temp gauge can read low. Air trapped in the cooling system leads to overheating. There is a bleed screw in the thermostat housing, much like a brake bleeder, loosen the fitting and let some fluid stream out to bleed any air trapped at the top.

Plenty of coolant and still overeating?

Run the bike from cold and observe the thermostat open, the top radiator hose will be cold at first and then get hot when the t-stat opens. If the engine gets hot but not the radiator top hose your thermostat is sticking or broken.

Try bypassing the electric fan switch. It's at the bottom of the radiator tank. It might be covered by a rubber boot. Disconnect the two wires from the sensor. With the ignition on the cooling fan should run with the two wires are touched if it doesn't you may have a bad fuse, bad connection or faulty fan. Next connect the fan switch wires temporarily and ride it, if the temp is under control you need a fan switch. The switches are on ebay sometimes or maybe the dealer. Many people bypass the fan switch with a toggle switch but you have to remember to turn the fan on in town traffic. You can also leave the wires connected and the fan will run whenever the ignition is on but your bike will be cold blooded not ideal but cheap.

 

And your water pump is on the left hand side, right by your shifter peg.

If you have water dripping under the water pump through a small hole, that means your water pumps mechanical seal is junk.

And honda doesn't sell that alone, but the whole pump assembly for over $265.

Cheers

LL

 

Yeah unless the cooling system can develop full pressure you will have overheating problems, just take it to the local radiator shop for a pressure test to find the leak.

 

Naturally your bike is guaranteed to overheat if your fan is not kicking on.

the fan switches fail even more often than R/Rs so use a manual switch.....

 

Cooling system overview

Operation - SabMagFAQ

 

Hey. thanks guys! lots of good info. I think i found the problem with the fan, so simple its dumb, corroded fuse.. cleaned it up and seems to work fine. I think I got a leaky water pump seal, not enough daylight or warmth to really dig into it here in northern PA.

The temperature gauge stays at just a bit over halfway.

 

My temp gauge doesnt move at all, The bike doesnt over heat, and the fan never comes on, Ive flushed all the coolant out, ran a radiator cleaning product, and filled it up with water and water wetter.



Ill try touching the wires together to see if the fan comes on, But what sensor makes it show on the dash? Is it the little one with one wire on the side of the bike. Were all the coolant hoses run together.?

 

Touching the 2 wires together did nothing, Ill have to check the fuse.

 

TO CHECK wiring and temp gauge BRIEFLY touch the wire going to the thermostat housing to ground (with key on).....gauge should show full scale HOT.

(MUST BE VERY BRIEF, like just 1/2 second only)