duct tape really wont hurt an engine if it gets sucked in. I have had leaves and other random stuff sucked into engines before. Really other than a bolt or something that won't fit inside the cylinder when it is on compression stroke it probably wont do much other than make it miss for a few minutes. I did drop a nut down a carb once on a sb chevy and it made a huge racket. I finally got a magnet and fished it out of the cylinder after probably 500 miles of hoping it would blow out the exhaust valve and it was beat into a perfectly round ball
didn't seem to hurt the engine much though.
__________________