It was running well for 1st couple summers. I recently changed out starter relay, but don't think that has anything to do with it bogging down. My boys & girls zip around pretty good. Seems like after 3 or 4 hours each weekend, we have an episode of it bogging down. My recent plug change I'm trying the 7ES plugs, a little hotter plug. I typically don't gap them just put them in as I was told they're all pre gapped. Is there something I can check for the fouling problem before I need to mortgage my house & take into shop?