I just had a Kohler canister air filter put on my 18hp Lazer HP about 3 days ago. When the engine is in a load (tall grass or uphill) the engine begins choking and blowing black smoke from the exhaust pipe. Before the new filter, I could mow ANYTHING and not have any problems with the engine choking down. One dealer put it on for me and it did this, so I got him to take it off and give me my money back. I then took it to my other dealer, and he said it was that it required a special carburetor adapter for the 18 Kohler. He put it on and the mower still does not perform properly, and it is getting to be a real pain. Does anybody know how to fix this?