17HP Kohler twin, MTD 48" walk behind, picked up 3 years ago from original homeowner with 250 hours to cut his 1/2 acre lot, overkill, now at around 400.
This spring during mowing it would start missing mid way into cut, so engine was warm, would last 3-5 seconds. All maintenance up to date.
Last week was different, probably 20 seconds of misfire, seemed to go away when blades were disengaged but still not enough time to get to the plugs to determine which one was not firing.
New plugs installed this spring after it started missing, didnt seem to make any difference.
Sea Foam, as in there may be a carb issue? Other than the occasional missing it runs strong, all the gas is used at a good pace, no issues when started in the spring!