try this ....let the tractor sit overnight take a clear jar and just barely crack the oil drain bolt and catch the first few drops  if its water  in the oil water will be the first out.   Gasoline will dilute with the oil and you wil have your milky oil mix first.
My bet is its water/antifreeze
	
		
			
		
		
	
				
			My bet is its water/antifreeze