Happy Holidays everybody! I am preparing my spad3D for its first flight tomorrrow and spent all day with the engine. I must have run 4 tanks of gas through it. I am comming from alot of experience with gliders, so I am kinda a neophyte. Got a few questions before I fly tomorrow.

Question 1: I am getting what appears to be black seapage out of the back part of the muffler. The muffler has two parts, a forward 2/3 and a back 1/3. The seapage is comming out through the seam. I checked the bolt/screw that holds them together and it is tight. Is this normall?

Question 2: Adjusting the idle. I think I got the high speed needle adjusted right. Once i give full power and it "spins" up, it seems to hit a peak sound and stay there. No wobbling in sound, nice and steady high pitch roar. However, when I go to advance from idle to full power, I got to go real slowly or it goes back to iddle and dies. I've tried adjusting the idler arm as they call it, but no matter where I go I can't seem to fix the problem. I have started form both ends and worked in to a sweet spot, but even then I have to go slow up to about 40% throttle till I can do whatever I want or it goes to idle then dies. The directions are no help, I did what it said and it's not working!! What's wrong? I am not a ME-262 pilot here ok! hehe

Question 3: The line from the muffler to the gas tank I guess puts pressure on the tank acting as a "fuel pump." Well, I am getting a brownish stain on the inside of the tank where that return line is. Is that normall? I also noticed that the wing is covered with brown spots from the exaust. The exaust gas looks whiteish. Is this the fuel or am i running it too lean/rich?

Those are "all" the questions I have. Only, hehe. Well, thanks for the help and Happy Hollidays!!