Go with what the plug tells you. Pro circuit is not jetting your engine, you are. If its rich, lean it. Start at the pilot, not the main. Hide the "porting" tools, do not do that anymore. Its not porting, making it pretty, making it seemingly flow better, shinier or bigger. Porting truly, involves altering the openings in the cylinder bore. A halve of a teaspoon of aluminum removed from the exhaust, could very well ruin the cylinder. Unless you can put it back to how it was before, down to the existing texture. I have done what you have, before, as have many others. To do it properly, you would need a right angle porting tool, a virtual 2 stroke engine soft ware program, and read up on every paper and SAE paper that Professor Blair, Eric Gorr and Rich Rohrich have written. Catch up work, they have done the hard part, and have already ruined plenty of cylinders. Its not like you figure, there is a specific volume and flow for a reason, scientifically and seat of pants proven. Eric has some very good basic manuals for 2 stroke performance, check out Forward Motion. And 2 stroke MX race bikes are usually engineered to the edge already, anymore and you will have a 10 minute rebuild engine instead of a 5~7 hour rebuild engine. That choice is yours. Vintage Bob