Diagnose my exhaust problem please.
 

I've ran my Redcat Rampage MT about 3-4 tanks so far, After it's first proper tank where I ran it continuously I noticed the rubber on the stock pipe had melted completely. So for the next tank I ran it without any exhaust, just the muffler and noticed black gunk everywhere. Does this mean I'm running the engine too rich? I have mixed the fuel to 25:1 like it says. Should I adjust my low speed needle to sort this out? I have fitted a tuned pipe to it now so I won't be able to visually see if gunk is exiting the exhaust or not so I just wanted to know if the solution is in the low speed needle setting or is this another problem?

Thanks.

if you are running no pipe/muffler, or a pipe/muffler that are leaking.... gunk is "normal". even the stock (black) can on the baja leaks all the time,

If that's the case then do people clean out their exhaust pipes as it'll build up with gunk eventually?

I know a lot of people at the flying club use a synthetic 2-cycle oil like royal purple for this exact reason. It burns a lot cleaner than petroleum based oil and does not leave a black mess all over the plane.

I've now started my truck with a CPI tuned pipe on there, tightened the screws thoroughly, used loctite and a brand new gasket. A few seconds go by and lo and behold there's gunk absolutely everywhere. Since I've used new gaskets, loctite, tightened properly and used a tuned pipe as well as a muffler and both times it's leaked, what's causing the leakage? Is it possible the pipe is not sitting flush on the cylinder exhaust port due to the cylinder exhaust port being warped?

Some images of the mess.

http://i59.tinypic.com/scqtsp.jpg

http://i58.tinypic.com/v4t651.jpg

You need some clamps on that blue tubing ;)
Otherwise it will ALWAYS come out there...

From those images, I'd suggest making sure that the cylinder is properly torqued down. I do not see any gunk on the manifold bolts nor on the manifold itself where the blue rubber coupling is. And there is splatter on the fuel lines behind the coupling with no trace of gunk on itself? You may have a broken gasket as well?

I put some silicone gasket sealant on the new gasket and also on the exhaust header, put it together and fired her up today, so far no leaks. Just hope when I go bashing it stays that way.