86 Vf500 steam cloud!!

Hey im a college student new to vfr world. I recently picked up a neglected 86 vf500 and have been fixing it up. I got it running a few days ago and rode it around a parking lot to see how she would run. Everything worked great until about 20 mins in the bike burst into a cloud of steam, i turned it off and after i turned it off I could hear a loud boiling sound. I assume its some sort of coolant leak/overflow valve problem but Im not sure where to start! Any help would be great. I'm new to the site and couldn't find a thread on this, but if you know of one and you could direct me too it that would be great too
Flan

 

Where did the steam come from? The front part of the bike. Could be rad hose bust,clamp not tight enough. Check both top-bottom hoses.

If it came from the center of engine area. Main plumbing for coolant. There are several small molded hoses and majority of the metal piping has O-rings on each end to seal in the block/caps. Thermostat cloud have stuck closed or partially. Which may have caused the problem. Or it was just an old hose/o-ring let go.

Left side by shifter is the water pump. It has gaskets and a hose to it. and the reserve tank above it under sider cover. Hoses there also.

 

Thanks
I checked the thermostat its working properly!
Just realized that the fan is not coming on , could the broken fan really cause it to over heat so much?
also i heard the same boiling again but no steam cloud
boiling is from further back on bike possibly from the reservoir but it stops real fast so its hard to pin point
any more advice on where to go next would be great
Thanks
Flan

 

The thermostatic switch that activates the fan motor is located at the lower left corner of the radiator. To test it, remove the plug from the thermostat and place a jumper in the connector, turn the ignition key on, the fan motor should run. If it doesn't run, check the black/blue lead for voltage. If no voltage, check for a blown fuse.

 

How did you know I used to be a hippie? :hippie:

Take the rad cap off, get it up to temp and make sure you have water flow. That will tell if water pump is working correctly.

 

great
Thanks for all the ideas, this site makes working on the bike a real joy
Ill go through the list and let you guys know
Flan

 

CLarification:

Unplug the one wire going to thermoswitch on radiator, and touch that wire to a ground point to check if your fan motor gets power and runs.

 

hey
I got the fan running (on a toggle switch, its ok to be hippie sometimes!) and it made a huge difference. I let it sit for a while to see how she would do and no problems, then rode around a bit and let her sit again and she stared to get hot! the temp guage got well into the top 3rd perhaps into the top fourth. Im not sure how warm these bikes are supposed to be so maybe im fine?
Is top third into top fourth of the temp gauge fine if i ride it then let it sit for a little?
Thanks again for all the help
Flan

 

2/3 or even 3/4 is actually pretty normal. Keep in mind that there is some gauge error and sensor error that can be had on a 25 year old bike. Mine runs like that on warmer days and in traffic. Just don't forget to turn that switch on and off!