Possible overheating problem

[Eagle700R]

Ok heres what happen..The 1st time the light came on i was on a incline and when i shut it down it went out..Rode that day no problems.

Came home washed her no worries.The next weekend a friend and i where practicing at a mx track it was really hot that day and again the light came on..Let it cool rode again light came on again.So i figured the fan was the problem.Sure enough the fan was bad.I took it to work and got it apart.It was full of dirt and the hose yamaha attched to it was routed up so every time i hit water or washed it it ran into the fan motor.I did a some what rebuild and put the fan back together reroute the hose.I let the fan run on the bench for a hour and no problems..Ok we go out riding and now the fan works and no light but now im getting some antifreeze from the coolant bottle.Heres the catch,the radiator is full and the collant bottle looks like it my have lost a ounce or so.I do know this it has to be coming from the coolant bottle because the hose is wet on the end...I have no white exhaust smoke,it runs really good I dont see any air bubbles in coolant bottle..Anyone have any ideas what it could be?Is it possible it can splash and run out? Just need to figure it out before going out of town next weekend..

[Krandall]

I personally had coolant splash out of the coolant bottle hose @ my XC Race. end of the tube was full of mud (dirt kicking up onto the wet antifreeze. I would keep an eye on it. But to me doesn't sound like you're in any big danger.

[Eagle700R]

Thanks friend for the reply..Im sure its probablly something small..Just hate to be clear up in michigan and something takes a crap..Would it be possible the thermostat be bad and if so how would it react it i just removed it.We used to do it on our supermotos and they ran fine but being this is a quad and ran differently ..I got a reply on another forum and they suggested the thermostat..

[Krandall]

I don't know enough about thermostats personally. Hoping someone else will chime in. I don't personally know how a thermostat would make the coolant bottle over flow. but I may have a bad one too then! 

[Colorado700R]

I would test the thermostat.  If the it's not opening properly you can get over flow.  I wouldn't take out the thermostat completely either.  Proper engine temp equals effciency, and an open system could cause a few diffrent problems (IE engine stays too cool, or too hot becuase the system is supposed to be pressurized), not worth it IMO.


you can use a kitchen pot full of water and a cooking thermometer to check if the thermostat is opening at the right temp 


Can't remember the temp for the Stat of the top of my head, but it must be in the service manual 

[Eagle700R]

Yea ill try that its a easy test..I have a service manual ill get the specs..Thanks for the replys..I wascurious if others have ran into this problem..hanks again.

[Krandall]

Is there such a thing as an engine running to COOL??? 

[Peelz]

a while back I was posting about my thermoswitch for the fan. FYI, last weekend was the first time I heard it come on the 660. 93 degrees outside and lugging through the timber. they do run pretty cool.

[preddy08]

Is there such a thing as an engine running to COOL??? 

Maybe not too cool, but engines run more efficient at higher temps.

[Colorado700R]

Is there such a thing as an engine running to COOL??? 

put a 160 degree stat in your Taurus and watch your gas mileage go to shit  :'(

[Bert]

Eagle700R
Did you reroute your overflow hose?

After I rerouted mine I noticed the coolant level getting lower...
A tip from Quad Magazine - cut all vent hoses at a 45 degree angle as its harder for them to plug