What color should engine residue be? I ask because my engine is depositing a grey, metallic substance on the wing of my Twist 3-D. I don't think this should be the normal color. I'm using Omega 10% fuel (pink in color). Is this normal break in residue or not?
On another note, my K&B Sportster quit today right before lift off. I just had enough runway left to land, but it made sort of a bang prior to shutting off. Now, it appears as though there is no compression like before. The plug is still good, and the piston still moves up and down...any ideas?
Thanks