Yeah, I know, you're gonna say this was dumb. And I agree. Had a plug foul out on the BR400 and didn't have a spare for it on hand. So, rather than cannibalize another piece of equipment for it, I stuck in a reular spark plug, the kind I use on the mower. DUH!! I noticed today that it was growling. So, I check the plug and it was loose! Figured out real quick that was because the engine had knocked it back out, seeing as how I couldn't get it to crank with it tightened all the way down. I noticed then that the plug was shot, gap bent, ceramic busted, etc. So, I tossed it and took the plug out of my push-blower, which fit great. Only, now it -really- growls and seems to knock/ping some. Not to mention that now it has about as much power as a Poulan hand-held blower/vac, on a good day. So, what can I do? I would rather fix it than just buy a new one. Thanks guys, blow me away!