I've got a plug fouling problem with my 2001 mxzx 440. I've owned the sled for 3 yrs so i have some knowledge of it. It keeps fowling plugs at mid to low range rpm. I've had the carbs apart and went through them and found nothing. It acts like they do when you forget to conect the small line from the carbs to the air box( did that once a couple years ago) seems to be the left plug mostly but once in awhile the right side also. Went through 8 plugs in about 40 mi. ( ya , I had that many along!) any advice on what to look for would be great. thanks, Jim PS, I'am running the low comp heads and pump gas, mixing 32:1