I bought a zero turn mower with the 25 hp Briggs professional series engine (model 440000) that is 6 months old and has 8 hrs on the clock. After I changed the oil to 5w-30 synthetic, it started surging when it is not under load. Is this just a coincidence or could changing to synthetic oil require a carb adjustment? Since I bought the mower used, I don't have a warranty. Can someone help me eliminate this problem ?
Thanks!
Thanks!