SO during hour like 4.5 of the 6-hour endurance race at summit my bike starts to over heat. Wasn’t sure then what the problem was but was pretty sure it was the thermostat. Now that im getting the bike ready for, well what ever I have a few questions. Well its only two. When we pulled over in the hot pit and the bike was over heating someone ask if I still had my thermostat installed. I said yes and they said that they don’t run with it in. 1. So has anyone removed his or her thermostat on their race bike? (no therm installed) 2. Do they make a race thermostat? Heavier construction or opens at a different temperature? best (aka cheapest) place to get one for a 2008 Kaw zx10R???
The thermostat functions to slow the flow of coolant even when open so that it stays in the radiator sufficiently to transfer heat properly. Take it out and the flow is too fast. That said, I have no facts regarding race bikes and am curious too. Actual smart guys will have to check in on this one...
I'm curious about this also. I've seen people cut out the middle of the thermostat so it's always open but it still slows down the flow. Waiting for the the engine builders/tuners to chime in on this...
The function of the thermostat is to prevent coolant from circulating until the engine reaches operating temp. At that point the therm opens, and coolant circulates to the radiator. In a race application, it will restrict coolant flow and can be removed.
Also: I look up my Thermostat and it opens up at (136 - 144) degrees... for some reason I thought it opend up way later...like in the 175 degree range. I also found out that my fan cuts on at (203 degrees) and cuts off once temps hit (194 degrees)... I run water with water wetter. I plan on just buying a new one, unless i read elsewise. I also can't wait to see what the builders do/recomend.
This is what I did to my race car engine's thermostat for (what I was told at the time) the same reason. But this was a while ago, so ideas may have changed since then. I've never had any issues with a racebike of mine overheating. I will wait for the real experts to chime in also........ Scott P.
As long as it reaches typical running temps, then running without the thermostat should be fine. During cold weekends though, your bike could end up running too cold and never get up to full temp. I ran without a thermostat in my cbr1000 years back, worked just fine.
I do not run it for one reason.. the slight chance that it sticks closed. Theres a reason most kit parts offer a thermostate removal kit.
You do not need a thermostat or fan on your race bike and both will do a dis-service to your cooling system under race conditions. There is not a single bike on any pro race grid that runs a thermostat. Ok that's not true, some 125 guys put one on so they don't have to mess with duct tape on the rad. Which brings me to the second point. On cold mornings just run a strip of duct tape over part of the rad. Use a temp gauge to make sure you're running in the proper temp range.
We use them, but gut them. The other thing is the cap goes bad under race conditions, so a new cap will usually fix the problem. And, remove the fan.
This true.. and your right....they can be removed...but are not always removed. There are plenty of bikes on the AMA grid running a thermostat for the reasons listed in Brians post.. Lots of people gut them so they still slow the coolant flow to allow the water to disapate the heat, but have no chance of failing. Different bikes require different things in different conditions.
The engine could also just be running lean making your engine run hotter. I would want to check out the rest of the condition of the bike before just removing a thermostat or gutting it.
^ gutting them is cutting the middle out and leaving the ring. there are some bikes where not having the ring installed will cause an error with the sensor.
My dad was telling me that last night. I told him I havent changed a thing and durring most of the race and all the races previous it was fine.
Moe - 1) Is the radiator fan still installed? 2) How long was the bike sitting on hot pit before it overheated? 3) Did it overheat while doing laps as well?
fan still attached and working just when it is suppose to (on at 203 degrees off at 194 degrees) The bike is pretty much stock with all hardware. I have a bazzaz FC, stock exhaust pipe with M4 slip on. Dyno Tuned sept 2008. I havent done anything different to the bike and durring the endurance race it was fine up until the 4.5 hour mark or so. We did have 2 red flags that caused us to pull in for some time. but it wasnt running hot then. It seems like all things point to the thermostat. Before I brought one I just wanted to see what the majority do. It seems like just replacing it mite be the best route.