This place really rocks!
Dave: It's set up to use muffler pressure, so no open fitting there. So methinks it's Brett to the rescue again!
Likely no problem with the front end (pending inspection). I have direct evidence that one of the owners (yours truly) was running this mill too slowly ("carefully"). I also have empirical evidence it has no muffler gasket.
So, here's the plan. Disassemble and give the antifreeze treatment to the block and muffler. Smoothen the muffler mating surfaces. Install a gasket. Finally, tac the thing out when running, shooting for something between 11,500 and 12,000 on the APC 11x5 prop.
Brett: You suggest header gasket sealant. What kind of material is that (a flat sheet of gasket material, goop in a tube, etc.)? Where's it found?
Legger of the Boot: Good point. On the last couple of bench runs, I used Brodak 5% nitro, 11.5% synthetic / 11.5% castor. But then much of the tarnish was already present from other unknown fuels.
I'll report back when all is said an done. Not sure what conclusion will emerge with my multi-pronged approach, though.
Thanks to you all..
Dave Mo...