[charleswrivers]

I hear it both ways... though if the popping sounds if it's carb it's likely to be lean, exhaust likely to be rich. Plug is the only way I know w/something w/o fuel injection. I'd read the plug from a WOT pull, and change the main to eliminate WOT lean, then adjust the mixing valve for in-between. If you're off on that, it seems to affect everything from idle, to going on/off WOT.