I was talking to the guy at the small engine place about what was going on with my snow blower, and I had mentioned that I put a new plug in shortly before it wouldn't re-start. He asked me what kind it was, and I told him it was some brand that I never heard of that I picked up from Lowe's. He said only go with NGK, or Champion. Can spark plugs make that much of a difference?
in general you can't beat an RJ19LM plug, or it's equivalent.
if you can find a multi-tip plug, with 2 or 4 electrodes, those are better yet. I use them in my cars and the set in my Chevy V6 now has 100,000 miles on the plugs. The resist fouling because there are 4 electrodes instead of just one, similar to what is used in aircraft piston engines.
FWIW the old Pontiac, Olds, Buick, Cadillac V8 plugs RJ8YC or plain old J8, will work in most of the old blower engines. these are as common as dirt. clean them up with carb cleaner, a wire brush, and gap them- they work great
but the RJ19LM is a specific short lawnmower plug that won't stick way up in the air or out the side, so the end doesn't get easily broken off, and it's a tad hotter in heat range to resist fouling. the main thing with these little engines is, a lot of low speed idling or work causes plug fouling over time.
Champion makes the best spark plugs, period. They've been making them for nearly 100 years and know more about spark plugs than all the other companies combined. their plugs have an anti-fouling coating on the ceramic. AC Delco plugs tend to foul sooner in my experience. Autolite, NGK, or ANY brand are ok in a pinch, if you can't find Champions, but if you have a choice, buy Champions.