my kato manual states that you should only use DOT5.1 fluid, or DOT4 if necessary.
dot5.1 has a wet boil point of 180 degrees C, and dot4 is 25 degrees C lower but will mix with 5.1.
never use DOT5 as it is a silicone based fluid and id dyed purple.
KTM gaskets and brake lines are not designed for dot5 and it should never be used!
hope this helps fellas