Hi Joe just thought I would share some of my thoughts
You say you have a shiny band around your piston , I see this as BAD bad bad, at most it should be a matt grey it being shiny tells me it is most likely cutting through the oil and polishing metal to metal.
Tight engines are great in cowled set ups like F3D where you can control the cooling , less air for very tight more air for loose engines doing this lets the tighter engines loosen through thermal expansion.
Your tight engine would probably best suit the hot dry conditions in Perth but in QLD with the high humidity you are almost water cooled and injected which is just over cooling a very tight engine. Try wraping the fins with coke can and give it a fly you might be surpised at how much better it may run.
What others have said about being smmmooottthhh is very important with thses planes , they are big draggy planes with low horse power and a big prop (10/6 for Aussie rules) and if you slow them down at No1 it will take the full lap to get up to speed again if it can.
One of the best quickies down here would be Jasons the OS in it has tram tracks up and down the liner and piston due to either flaking nickel or the tang of the bearing cage but it is always run a little rich so that if it is loaded up it has the fuel to not lean out and pull through the load. Also he flys very smooth other wise his caller tells him off. It is set up to do a full up turn at both ends of the coarse and can catch out some No1 cut judges as the plane starts its turn before the pylon but still makes the distance and by flying it like this it loses little speed and probable speeds up for the first few laps.
And as someone else said 2 stroke engines always seem to go there best just before blowing up or falling over the edge of performance
Hope you can get something out of this
Terry