Tips for containing the spooge - KTM's without o-ring sealed exhaust flanges.
First off, for all you non-KTM'ers reading this, get'cher mind out of the gutter.  We're
talking about that black oily crap that oozes from the cylinder/pipe junction and drips
out the back of the silencer or spark arrestor.  Newer KTM's have O-rings on the
exhaust flanges, so those of you lucky enough to have such bikes don't have to go
through the annoying rituals described below. These tips apply to the KTM's that
do not
have an O-ring exhaust flange. Without the O-ring, the end of the pipe fits over the
exhaust outlet, metal-on-metal, with nothing keeping the black stuff from leaking out.  
Also, the pipe fits
around an exhaust flange, which is not as effective as having the pipe
fit
inside an exhaust flange as with the newer KTM's and most Japanese two-strokes.

Solution #1
Put a layer of red high-temperature silicone on the outside of the exhaust outlet, put
the pipe back on, and let it dry for a day.  I would not recommend putting the silicone on
the
inside of the pipe.  When you push the pipe over the exhaust outlet, the excess
silicone gets forced into the pipe, dries up, breaks off from exhaust pressure, and then
gets stuck in the end of your spark arrestor (if you have a silencer, this is probably not
a problem because it would blow out unobstructed).  This method will work until the pipe
gets a couple of rubs against rocks or other hard objects, and then you'll need to
re-seal the junction with more silicone.

Important tip:  clean both surfaces until they sparkle,
then apply the silicone.

Solution #2
Convert your exhaust flange to the 250SX version that has an O-ring.  The part
numbers are:

547.05.003.000 (exhaust flange)
0770440030 (Viton O-ring for the flange)

Total cost should be about $20.

CAUTION:
I can only guaranty that this will work for the 2002 300 EXC and MXC - for other
models, use at your own risk. Also, the O-ring flange has a smaller inside diameter than
the stock flange.  This smaller opening will improve bottom end somewhat, but will
take away some top end power and force you to re-jet.

Spooge out the spark arrestor
No good solution here, but one that helps is replacing the stock spark arrestor with a
silencer or an FMF Turbine Core spark arrestor.  I chose the FMF Turbine Core, which is
shorter in length than the stocker, so at least the spooge doesn't drip onto the rear
brake.
Got Spooge?