Question : My Snapper riding mower with a Kohler engine chokes-down and begins to backfire, speeds up, slows down, when it gets hot. What is the problem?

Answer : Is it hard to start or won’t start when it is hot? It has a single coil feeding both cylinders, The coil could heat up and cause problems, but I think you have a valve problem. The valves over time lose there clearance and don’t seat when hot. Causes power lose and makes engine hard or impossible to start when hot. The valve covers are on top of the block just behind the cylinder head, two rectangular covers, about 2in. by 4in. one will have the engine breather tube in it the other will be plain. The valves need to have .006 in. clearance. With any clearance it should run, but I think you will find you have zero clearance. The only way to adjust the valves id to remove them and grind the tips off. This involves removing the heads and then the valves. Let me know what you find. Thanks.

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