Interesting..no, I have not had that happen...yet...I think. Although I did modify mine a little for the filters I am using...but I have s small mystery I haven't figured-out yet. Seems even with double filters I for some reason still get this small, weird build-up on the upper edge of the throttle plate that looks like what you would see when dust gets through...but taking it and looking at it under a digital microscope, it looks like.. well.. grease. I can't see any dust or grit particles. I just assume it's from the oil in the filters...but maybe it's something else.