250-500cc 2011 wr 300 thermostat

how will the thermostat help bikes in warmer climates. That is the claim but it seems contradictory. i ride in the southeast and don't want anything to overheat. thats is why i was thinking of going back to 2 stroke over four stroke for the peace of mind in the overheating department.

The idea behind it is that when the thermostat is closed, the radiator has more time to cool the anti-freeze that is sitting in the radiators. Thermostats are good things on dirt bikes in my opinion. Fans are good things riding in the east as well.

I thoght it was to get the bike warmer in cold weather! Wouldn´t the engine overheat if it keeps the water without circulation in the cylinder and cylinderhead?

Me too???

I always thought it was for both. I do know in cars that they run cooler in the summer months with a thermostat.

Yes, of course it must correct the temp under all conditions, but i can´t see the benefit of keeping hot water without circulation in the head and cylinder just to let it cool off in the rads. Wouldn´t that make the engine work under very different temps? Bad for pistonrings, less power?

Johnny

i never liked them in the KTM's and not in Huskys either...its another part to screw up....you only need a thermostat for 5-10 minutes until your bike is warm unless you are riding in extreme conditions...personally I would loose it, just like we did on KTM's

I am not sure how the thermostat in a Husky wr 300 is set up. The one on my ktm exc 200, 2004 version is in line on one radiator and came with a plastic block off sheet to place in front of the non thermostat radiator if desired. It would seem one could put something in most any bike like this and no need to pick a particular model.

Ideally with a thermostat the engine will always be at a certain temperature or at least the coolant so the tolerances might be able to be made tighter.

The greater the thermal gradient the more heat is dissipated. everything else being equal.

The heat is exchanged more efficiently when the coolant is held in the rad a bit longer. The big benefit is that fuel mixture can be more accurate/ideal because the engine temp is always the same no matter the outside temp.

Ok, so less circulation gives a cooler engine?

I think it would help, my 300 rarely gets above 200 even in the summer and the temp can vary 40 degrees or more which can't be good for jetting.

I've not seen any pictures, can the thermostat be retrofitted?

As Frank...k hit on it has to do with the difference between the already cooled coolant being a greater temp difference than what the engine temp is. When no thermostat is used the incoming coolant may only be a couple of degrees different than the engine itself which is not efficient. When the coolant is held in the radiator long enough for there to be a bigger difference (say 30 degrees) it is much more effective at dropping the engine temp. It's not less circulation that helps but a more efficient process of exchanging hot for cold coolant in the engine and then slowing the circulation long enough for the heat to exchange and then repeating the process.

I have never found a thermostat in my Husky? where if anywhere would it be in an 09 450?

BillF has the new 300 in stock. I'll see if I can get a picture tomorrow. My riding is 80% at under 65 degrees and the long downhill trails really cool the bike off. I wonder if it would even help the WR150 stay up to normal operating temps?

I agree completely

+1. What Kelly said...

Ok, as i thought then. The engine runs warmer! My 300 runs very cold compared to a KTM 300. I have to block one rad even if it´s around 50F to get it uop in temp. On the ice i almost block both completely! And when i check with my Pyrometer i am between 60-70 Celsius.

ok, well after looking at where it is on other bikes, Im going to assume I dont have one, lol.

I guess I should have stated that my response was to thermostats in general as I'm not familiar with the specific set up that you are asking about. From Kelly's description it sounds kind of Mickey Mouse and I would probably remove it. That said if it was set up like an automotive thermostat that would regulate the coolant at a constant temp I think it would be a good thing for performance.