When is it time?

I have a 2001 400 exc.

I'm having some rusty fluid leaking out of the hole on the right side of my cylinder. It's not much at all and it just does it sometime. My question(s) is (1). Is this the water pump seal (2). When should I start to worry about it? (3). Does the 2002 parts work? Which parts(besides the 2 seals) need to be replaced? Thanks all...

If it is on the right side(as you are sitting on the bike)it is the drain hole for the spark plug. KTM puts that hole there so you can clean around the plug before you remove it.If it is on the left side that is the water pump seal. It should not be rusty,unless your coolant is rusty. The updated 02 parts are still on back order so you have to use the 01 stuff.Which side is it really leaking from???

Here's my take. The spark plug clear out hole is trapping water behind your crankcase breather hose. When the hose is moved, say when drying off your bike, it leaks out the rusty liquid. It is really no big deal. Move the breather hose out of the way and it will probably not happen again.

The one I'm talking about is on the right side (Kick starter side) 6 inches due North of the Oil dip stick. So I can just blow that out with an air hose?


My 400 EXC retains water in the spark plug well that does not drain. After a wash, I routinely remove the spark plug wire and blow-dry the well. Then fire it up and ride until it reaches operating temp. Afterwards, I remove the spark plug wire to allow any residual moisture to evaporate.

Yup, thats just a water drain hole. It's at about a 45 degree angle in. Pop the sparky, blast some brake/electrical cleaner in there (with the plug in!!), then blast into the little hole with an air gun. All kinds of crap can come flying out of there, so watch your eyes!! The rust is just the outside of the plug getting grungy. I bet when you change it, it will look like it came out of an episode of Junk Yard wars rather than your baby bike.

Spraying a short burst of WD40 in there after riding/washing helps keep the plug nicer, and forces the water out, just not too much, could catch fire next time you start her up!

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