Originally Posted by
Meschmidt
All my engines have Champion, Bosch, even some with no name but just numbers. Some have 8's or 7's on the number. Are the plugs not just the size, but different heat ranges to them? Will the NGK BPMR7A work on any engine as long as it fits the hole and the cap? I have US 41, Quadra, Poulan, Zenoah, BME, Husqvarna... They mostly have different plug numbers but they are different brands too, so that's why I'm confused.
Just my 2 cents on this, use the plug designed for the application. If it was designed to run on a Champion XYZ, use the Champion XYZ, and don't deviate. Small engine ignition systems aren't exactly picky in the same way automotive ignition systems have become but its still one less thing to worry about. Since you've interchanged plugs I wouldn't be worried so much about the brands as the differences in things like heat ranges and electrode depth etc.. having been installed in engines designed for something else.