VFR overheating and dropping all its coolant

in a large crowd of bikes riding at a slow pace (in first gear) for about 25 min, My bike started to overheat very quickly reaching 125 degress then started dumping coolant. It got up tp around 133 degress before i could get out of the pack. Once i was on some clear roads it cooled down to around 100 degress and stayed there. When i got home i checked the coolant bottle and it was completely empty (ie it had dropped all of its coolant). Just wanted to know if this was something anyone else had come across and if you had any suggestions to fix it.

 

133!!!! you mean 233.....mine averages between 217 to 240 sometimes.....from what i have read the vfr is made to run hotter than you traditional 4 cylinders....makes the balls quite warm but always runs fine.....as far as dumping coolant that sounds like a thermostat.....if not the thermostat the next is possibly much worse....eek....a head....from my experiences.....i am an ok mechanic....i used to work for a dealership then some other small garages.....newho.....make sure ur resevoir is not slam full when u fill up the radiator....there are those lines on the bottle for how much to put in it....hope all goes well

 

Yeah that sounds like a thermostat problem. It's a relatively cheap fix, the thermostat costs around $35 and they have to be replaced every 2 or so years anyway. Don't forget to also buy replacement o-rings for the connectors as well.

However, if you want to fix it yourself, be warned, it's a real time-consuming process because you have to take the tank, airbox, and throttle bodies off to get to the thermostat. The service manual shows you how to do it and if you've never done it yourself expect it to take at least two days so I would clear out a whole weekend to do that. Putting it back together is just as difficult because you have to do it exactly right otherwise you have to take everything apart and start all over again.

This topic has been discussed quite a few times and try doing a search for thermostat in this forum. I recall one member even wrote up a how-to on this.

 

The very same thing happened to me last summer. I had been warned, but I did not listen until it was too late.
Change your thermostat before you ride anymore. The job takes about 3 hours if you have the right tools and some knowledge. The hardest part for me was getting the throttle bodies off. everything else was fairly straight forward. Action(the member) did an excellent photo write-up on this job that helped me beyond measure.

http://vfrworld.com/forums/maintena...acement.html?highlight=thermostat+replacement <linky

 

first thing to check is thermo switch that makes the fan run since they are unusually prone to failure and will cause exactly what happened to you
next check radiator cap
be aware that the cooling system must be refilled both at the rad cap and overflow bottle

using a manual switch wired in parellel with regular thermo switch would have likely prevented this mishap.....

 

nah it was 133 degress celsius not faranheit, im going to get a major service before i ride again and ill change the thermostat as well. Thanks

 

Wow, 133 celsius is really hot, my conversion puts your bike at 271.4 degrees Fahrenheit.

That's the hottest I've ever heard a VFR getting - did your fan come on at all?