Kohler sv735 running rich blowing black smoke. Left and right wires have spark but when I pull right plug wire there is no change in engine sputtering and knocking. No metal in oil. Pull the left and it dies. Backfire when turning off. Thought I saw a yellow spark from back of motor when I started it once from around the starter area but not anywhere where I could see any wireing. At one point after I pulled the right wire off and started the motor a red wire on the right side tied wrapped to the plastic intake manifold arcked from one side of the connector to the other but when I put the plug wire back on it did not arc any more. Any ideas?
Tring to bring it back after sitting in the weather for about 2 years. Courage only has 130 hours on it.
what tractor is it on?