Hay David:

I'm using a TigerShark .91 red head and it's a monster. The weight with the pitts muffler is around 31 ounces.....Heres an interesting thing My scales will only read up to 5 lbs, so I can't weigh the bird all together. This thing is supposed to weigh around 8.25 to 8.75 lbs RTF. Now the fuse RTF weighs 4 pounds 15 ounces and the wing RTF comes in at 2 lbs. my sifering brings the bird RTF in at 6 pounds 15 ounces. Wonder whats wrong??
Heres a couple of picts, check it out.