The model number of your Kohler used on that model is a CV750-0026. Attempting to switch engine models is not a plug and play system. You will need to order a new muffler and and new wiring harness to start with. The machine is 5 years old and I would re-think about switching engine manufacturers. Replacing the engine with the proper set-up is much easier. It may not be the engine of your choice but you wont be spending money you can't recover.