03 REV 800 sport all stock, after an hour trail ride, good conditions, i stopped for 15 min break. Sled starts right back up but immediatly fouls the left side plug. Plug is wet, put in a new one and runs fine. I do not know the compression, have not checked but RER works so I assume it is ok(from what I have read if compression is low it will stall out). This has happened twice recently. Running BR9ES plugs, is this the best plug to run ? Trail riding 40-50 mph occasional full pull on a road.