Kohler Command CV23S

[Backfired]

My Kohler Command CV23S has 840 run hours on it. Three weeks ago I was cutting the lawn and it was running fine. Suddenly the engine RPMs dropped and the engine began to backfire and blow black smoke out of the muffler. I changed the gas filter, and sparkplugs. Both cylinders show a strong spark and seem to be getting gas but only the one by the fuel pump delivering power with each spark to that plug. The other cylinder is backfiring with each spark to its cylinder. Has anyone had a problem like this before and how did you fix it.
Thanks

 

[ILENGINE]

Remove the valve covers and make sure you haven't bent and dropped a pushrod.

 

[Auto Doc's]

Hello Backfired,

Remove the air cleaner parts and check the choke plate for sticking partially closed. I dealt with that problem on my own CV-20 last week. The cross bolt for the choke activation lever was stiff and had dirt buildup preventing the lever from operation properly.

The pivot bolt in the lever mechanism had a nut on the back that has to be held, and it is a little tedious to get too but it is possible