Re: Enginaire for 15hp Kohlers Mow Ed, I bought 2 of the same units for my 15hp Kohlers & took them off soon after. Dirt was getting past the gasket somehow & into the throat...the filter & pre-filter was spotless but there was a fine layer of dirt in the throat. I got replacement gaskets but the problem persisted so I threw them out. Have you inspected the throat & if so did you notice any dirt stuck to the sides? Also if you take off the bottom plate do you see allot of dirt under the plate on the filter base?....I did. I will not use Enginaire again.