Hellblaster:

I am not the first to put down glass cloth -- I think there was a fella earlier in the thread who used a half-round cardboard tube as a guide and put down some cloth over that. My YS110 came to me used and only included the pitts style muffler -- no stock one. Therefore, in puting the motor in, I had to remove about 1/4 of the bottom of the firewall, to allow the muffler to be connected -- it still isnt quite right as the pipes come out at about a 20-30 degree angle to the side instead of straight down. THe wood that was cracking was the bottom piece -- not the firewall. I suspect it cracked because my YS shakes very very much (working on that) and I removed the support of the firewall and I believe the motor was shaking so much that the muffler was coming into contact with the wood during the vibrations. Anyway -- The glass cloth was put down on the front floor of the showtime so that the wood would be stronger and also as a preventative against fuel coming in -- it's not sealed and is open in places. I vowed not to take pictures of it cause its an ugly job and I'm really not too proud of it, but will take some shots today sometime and post them with a flight report hopefully.