Ok, according to partstree, the correct spark plug is kit 50-1170. If I search that number, it gets me to the NGK BPMR4A and I believe that is the plug that is in the machine right now. I would have been ok with that but the BUMBLING local parts guy lead me to the champion model stated above. On first inspection of what he gave me VS what was IN the machine got me to ask the question on this forum. Looks like the local Advance Auto parts store can get these NGK plugs for less than 3 dollars (instead of paying partstree and other stores 8 dollars for the 50-1170 kit).