I have a sportsman 600 that this winter while plowing I noticed was doggie so I was gonna do a tune up and when I went to change the air filter the air box had about 1/2 inch of coolant in it I cleaned it all out and went about my way checked It the other day and there is about an 1/8th on there again I watched as it ran and is seems to come from the breather line from the head/valve cover. What could cause coolant and yes its coolant it is sweet to taste.