Operating temperature of WR450


8 replies to this topic
  • fatcrackers

Posted October 14, 2009 - 03:45 PM

#1

Anyone know what sort of temperatures I should expect when running my 2005 WR450?

I've just bought a Trail Tech Vapor which includes an inline coolant temp sensor. I've added the sensor to the hose running from the engine back to the radiator (left hand side... when sitting on the bike). Vapor allows me to set a "high" temp and a "danger/warning" temp (which triggers 2 different LEDs). The problem is that I'm not too sure what sort of temp is considered "high" and what is considered "dangerous" (ie. stop the damn bike).

To give some background, I also use the bike to commute to work and a couple of times the coolant has boiled (from sitting in traffic). I don't have this problem anymore as I just kill the engine whenever I'm sitting for a period of time. Seeing the temp with some reference to being high or dangerous is much better though. Cheers.

  • byggd

Posted October 14, 2009 - 03:53 PM

#2

My 426 have a Vapor installed. I set the yellow at 200 and the red at 240.

  • fatcrackers

Posted October 14, 2009 - 04:08 PM

#3

Thanks for that.. those temps probably sound reasonable. I'm guessing you're talking fahrenheit and not celcius... otherwise I reckon I'd be in some serious trouble if I hit 240C :bonk:

  • Alternative

Posted October 14, 2009 - 10:56 PM

#4

Yes he's talking in fahrenheit. I set mine at 110 and 125°C respectively. 200°F (93°C) is about proper operating temperature so I think it's a little low for a "high temp" indicator.

Visit the ThumperTalk Store for the lowest prices on motorcycle / ATV parts and accessories - Guaranteed
  • byggd

Posted October 15, 2009 - 04:17 AM

#5

Thanks for that.. those temps probably sound reasonable. I'm guessing you're talking fahrenheit and not celcius... otherwise I reckon I'd be in some serious trouble if I hit 240C :bonk:

G'day mate! You are correct, "fahrenheit" here in the US :bonk:

  • PBDBLUE

Posted October 15, 2009 - 05:53 AM

#6

The boiling point of 50/50 ethylene glycol at sea level is about 266F with a 1.1bar (15.6psi) cap. It will drop about 1 degree for every 1000' elevation. For instance at 10,000' it will be roughly 255F. As long as it's not boiling the engine is being effectively cooled.

  • grayracer513

Posted October 16, 2009 - 09:20 AM

#7

The boiling point of 50/50 ethylene glycol at sea level is about 266F with a 1.1bar (15.6psi) cap. It will drop about 1 degree for every 1000' elevation. For instance at 10,000' it will be roughly 255F. As long as it's not boiling the engine is being effectively cooled.

And with that, for most any liquid cooled engine running a similar mix in the system, the yellow should be around 220-230, and the red at 250. Below that, it's safe.

Most dirt bikes don't have thermostats because they are generally ridden pretty hard by comparison, but the truth is that there is such a thing as over cooling an engine. If the coolant's not at least 160 degrees, the oil's not likely to get hot enough to purge itself of volatile contaminants. An engine is also more efficient when it's hotter, and keeping the coolant too cool is doing nothing more than stealing some of the heat energy extracted from the fuel.

  • PBDBLUE

Posted October 16, 2009 - 01:51 PM

#8

And with that, for most any liquid cooled engine running a similar mix in the system, the yellow should be around 220-230, and the red at 250. Below that, it's safe.

Most dirt bikes don't have thermostats because they are generally ridden pretty hard by comparison, but the truth is that there is such a thing as over cooling an engine. If the coolant's not at least 160 degrees, the oil's not likely to get hot enough to purge itself of volatile contaminants. An engine is also more efficient when it's hotter, and keeping the coolant too cool is doing nothing more than stealing some of the heat energy extracted from the fuel.


Agreed. 250 is a good redline. Just trying to put a little science behind the myth! I have mine set 190 at yellow to remind me to switch on the fan if needed and red set at 245 just to give me a little extra warning. I haven't had a chance to ride in overheating conditions (i.e - hot, slow and high altitude or any combination thereof) to really see how effective the fan is going to be but I can idle it in the garage for 10 minutes without hitting 200.

  • fatcrackers

Posted October 20, 2009 - 03:43 PM

#9

Thanks for all the info. I'll probably set my yellow at 203 (95C) and red at 245 (118C). I also use this bike to commute and can get stuck in traffic with an ambient temp of ~86 (~30C). When summer hits this will be closer to 104 (40C). By setting the yellow early it should give me enough time to keep an eye on the temp and consider an alternate route, to keep the bike moving. Perhaps one of the Spal fans would help. Or perhaps I should finally concede that I need to get a cheap road bike also.




 
x

Join Our Community!

Even if you don't want to post, registered members get access to tools that make finding & following the good stuff easier.

If you enjoyed reading about "" here in the ThumperTalk archive, you'll LOVE our community. Come join ThumperTalk today!

The views and opinions expressed on this page are strictly those of the author, and have not been reviewed or approved by ThumperTalk.