Picked up a John Deere SX95 with a Kawasaki FB460V. Mower has been sitting for over a year but the seller assured me it was running when parked. When I tried starting it with starting fluid it would cough from the carburetor and muffler. Could both valves be stuck from sitting? Haven't done a compression check yet because it's too cold to work outside. Just trying to get some ideas before spring. Thanks