Yeah, I was beginning to worry about the gunk on the crown. If it were brownish, I woulda been OK, but it was
BLACK. It wasn't all over the crown - just the flow pattern area. But it alarmed me some. The top of the piston did go cleaner after I ran Power1 Racing in it. We should also keep in mind this was a super high compression, finger ported cylinder that was Randy's own saw. And she liked to run hot. I had to sell her off - too hot a saw for a working saw. I think in a typical 044 you might not see as much benol combustion in the chamber.
BTW, Maxxima Castor 927 cost significantly less here than K2 does. It also cost less than Stihl Ultra, and half what Castrol 747 does. I've not seen Klotz or Amsoil here. I would love to run Techniplate. Hrm... I may invest in a 500ML bottle of 927 to run on occasion to plate the P&C a bit after I clean it up and install the new piston.
Not the best pic, but you can see some black in the exhaust directional arrow on the piston top and the swirl pattern as well as a touch of carbon creeping in on the exhaust port in the lower right there:
And this is what the piston side looked like after 5 gallons. The muffler itself came a bit darker as well. You can see it speckled with carbon.
The Bosh Chinese plug Randy sent with it after 5 gals of 927: