I have an Exmark 52" 27hp Kohler. It just stopped running. I pulled the fuel filter and it was clear, I replaced it and took the line off after the pump and got no flow when I cranked the engine. I went to my dealer for a new fuel pump. The mechanic, a very knowledgeable fellow gave me a Briggs pump part OEM # 808656. He said it was "exactly the same pump as a Kohler for 1/2 the cost. I asked for a new fuel filter and instead of a Kohler he gave me a Stens made for a Tecumseh, he said it was a better filter. I replaced the filter and pump and it cranked up fine and even seemed to give me a few more rpm's from the sound of the engine. HOWEVER when I got to some thick grass the engine started to bog down. Now I was never able to bog down that 27hp Kohler before, and this was not that heavy of a lawn. It did this twice and started right up after it happened each time. So for the heck of it I went to some heavy grass, now it would have cut this without a whimper before. I went through it slowly about 1/2 speed, and it bogged down right away. Did putting this Briggs fuel pump and Stens filter effect the power. This was suggested from the head mechanic at the dealer I purchased this from. Obviously I cannot contact Kohler. Any ideas?? Am I hurting the engine?? I appreciate any thoughts or advice.