I am having the same trouble, after many failed starts, now getting the black oil from flex pipe and backfire. Don’t even know where to start. Hope someone responds, need to race this weekend.

If you had a lot of failed starts, my guess is the engine was flooded badly. The gas evaporates, leaving an excessive amount of oil that is now blowing out the exhaust. The oil won’t damage the exhaust pipe.

Thanks Dan !  Is that also causing my backfiring condition?

No.  Are your truly “backfiring” or is the engine missing?  What ignition system are you running (push button box or key start?).  What are the settings (number of turns) on your carb?

Incidentally, splatter and leakage and general “spluge” from a 2-stroke exhaust is pretty much a fact of life. Had it in my Honda shifter; had it in my Leopard.  The only question is where will it come out?  On my Honda the weak point was at the exhaust port.  On the Leopard it was the flex.  My X125T is very well sealed, so it comes out at the end of the muffler and I wipe down the end of my bumper a lot.

Jim, Backing firing seems to have cleared itself after proper adjustments. No longer leaking crude oil at the exhaust flex. Key start and always open for suggestions on low and high turn out.  Thanks for responding.