I just pull the kids around with their sled but I've taken it to a shop and they don't see anything wrong. Cleaned carbs, put new plugs in, sometimes it runs smooth when throttling but most of the time "dogs out". Any obvious suggestions?
Yeah, you could try the 8's and see what that does. Since you just pull the kids around in the yard, your not really getting on it enough to clean it out and heat it up much. Hotter plugs might be just the ticket. Hey, one more thing, check your choke cable free play with the choke in the "off" position, you should have about an 1/8" of play. It wouldn't hurt to pull the plunger out of the carb too, just to make sure it's clean and closing freely.