[motogroove]

Prompted by the paper towel incident and a hint from the
"Internally cleaning exhaust " thread where AZRickD wrote:
"As far as cleaning the silencer, the one thing I look for is old disintegrated packing in the very back of the tube. That packing can pack up back there and restrict the exhaust flow reducing low end torque as well as upper revs. I use a metal hook to clean it out. "...

I went one step further and drilled the four rivets on the powercore2 and did a full soak and inspection. In the picture I'll call the parts the body, the main tube, the turbine, the tip and the cap.
As Rick predicted the turbine's exterior was packed with old spoogy disintegrated packing. This might not be surprising around the perforated area that fits and works with the main tube. But I was surprised to find a large amount of superfine spoogepack on the closed end. I guess I shouldn't have been surprised because that area is part of (or open to) the flow path.

Roughly a decade's worth of spoogepack in there was taking up ~1/4 of the volume in that little cavity. If nothing else, it's weight.

If you are on an older bike, you might want to drill down on your silencer.

BTW, my carb was a complete mess at the race. Somehow the carb cleaning was checked off on my list. But when projects drag out for months, things get stupid fast. <:-)