Geistware, just curious, as much as you fly, why would you add a fuel stabilizer? When I was building custom cars, with aspirated or injected engines, I cautioned my customers from using ANY type of fuel additives. Cleaners, and ESPECIALLY a stabilizer.
A fuel stabilizer "isolates oxygen" and prevents it from escaping the fuel, therefore, neutralizing the corrosives in the fuel. Now think about that, anything that surrounds and encapsulates the oxygen in the fuel is going to inhibit the flash point of the fuel, and anything that neutralizes corrosives, is going to neutralize something else, (like lubricants). I have found that a fuel stabilizer can and will coat the surface of the piston, and sleeve, and can cause valves ( in four strokes), and rings to stick, and in some cases even beak.
Remove the spark plugs, try squirting some carburator cleaner in the exhaust ports and the plug holes, with the spark plugs out and the engine inverted turn it over a lot while constantly spraying cleaner in the exhaust ports. After the fluid turns clear, squirt your favorite oil, unmixed, in the sparkplug hold and rotate to coat all surfaces. Replace plugs and fire her up. see if that helps.

Just an idea. My .02 only.

Wayne