water in radiator and reservoir
 

NEVER believe your reservoir bottle.
This past weekend i picked up small water leak at bottom of my water pump. riding on and pushing further with a watchfull eye on the reservoir bottle i had to carry on till i get to place to fill bottle.
The bike started to overheat andf light came on just as i got to garage to top it up.
Topped up the reservoir and carried on, but overheat light came on about 5km after garage. Luckily a friend of mine advised that his KTM did the same and water was not stored in reservoir to "top up" reservoir, but reservoir is there to catch overflow of water. To make long story short, i opened radiator cap and it was bone dry. Added water, waited for bubbled to come out, started bike and ran for short while, filled it up to the top and off i go....all sorted.

My issue here is why would i need to check my water level daily before every ride if the reservoir is not true and acurate?...i must check my radiator , not the reservoir....

Yea i second this, i got a leek in my hose from the radiator/pump and took it easy to get home. End up filling the radiator with around 250mm of water but the level in the bottle never changed. :eusa_eh:

While the radiator is pressurized the over flow bottle will not fill the radiator.

The only time it can full the radiator is when the cooling system has cooled down completely & is causing a vacuum on the system, this will draw the coolant back into the radiator from the over flow bottle. If there is a leak in the cooling system the vacuum effect will not take place & the over flow bottle will remain full with the cooling system empty.

Good explanation and i understand, but in the real life this is not practical.So what you are saying is that when your bike overheats, you need to wait for it to cool down for hours untill it will "suck" water into the radiator.
Out in the field or on a long trip this might be difficult. From now on, i will be checking my radiator instead on relyijng on the bottle indication....something for Yamaha to think about changing in future.
GB

This design has been around for a long time & is in use on many vehicles, cars, bikes ETC. It works well until you have a big leak.

Untill we leak again then....
cheers

Having water pump leaking problem, I have just checked the radiator and coolant level was fine. Immediately after, radiator cap start to leak. I found that ruber on the cap is starting to destroy even on slightly touch. Replaced with some piece of old inner tube. Bike is 2007 xtr. It shouldn't happened. Thinking about quality of cap, maybe opening valve with inaccurate pressure is rensponsible for failure of mechanical seal?! :icon_scratch:

Damn KTM parts.:bricks: