ktm 640 cooling system !!!!

[wayne640]

Howdy is there a correct procedure of changing the coolant in a 640 ?, have checked the index to no avail.

I know my 300 exc needed to be bleed after the coolant was changed, is the 640 the same ?

Anybody have a guide to it, and wich bolt is the coolant drain.

cheers

[Odysseus]

Originally Posted by wayne640

Howdy is there a correct procedure of changing the coolant in a 640 ?, have checked the index to no avail.

I know my 300 exc needed to be bleed after the coolant was changed, is the 640 the same ?

Anybody have a guide to it, and wich bolt is the coolant drain.

cheers

There is no "coolant drain" other than removing the lowest coolant hose and letting it drain. I use a funnel to try and direct as much as possible into a bucket.

If you are going to drain it I suggest giving it a good flush as well. I use the procedure described on the Engine Ice website:

How often do I need to change it and are there any special requirements?

Most every coolant product will work best when changed somewhat regularly…at minimum, we’d recommend once a year.

For racing applications, we actually recommend twice per year. The cleaner you can keep your cooling system and the fresher you can keep a fluid, the better it will perform.
There are no special requirements for using Engine Ice.
For any coolant and anytime you are changing coolant, we recommend a simple solution of distilled water and white distilled vinegar, both available at your local grocery store.
1. Mix the water/vinegar at 50/50
2. Fill system with the solution
3. Run engine until warm
4. Let cool
5. Drain
6. Run clear water through to rinse out vinegar.
7. Fill with coolant of choice.

This is the same as cleaning your coffee maker. The vinegar is acidic enough to clean out and contaminants and residual coolants, yet it won’t harm your seals and gaskets.

[wayne640]

cheers for that so do you need to bleed the system after you fill it ?

[gunnerbuck]

I've changed out my coolant several times on my 03 and never had to bleed it. I ran it with the cap of for a bit and then topped it up to just above the tubes. I then checked it frequently for the next couple rides to make sure the level stayed there and it did.

[Odysseus]

I lean the bike over to both sides after filling the radiator with new coolant. A few air pockets usually get released by doing that. You can also just ride it around for a little while then top up the radiator when it cools down again.

I believe the term everyone uses is "burp"

[wayne640]

Ok seems a bit strange there isnt a bolt on the motor somewhere so you can drain the block of coolant.

To me just undoing the bottom hose is fine for the radiators, but what about whats in the motor ? As the radiators are higher than the motor.

[fujian]

Old Thread, I think the cleaning out with vinegar is a good idea. I'll be doing that then filling up with liquid coolant.