Here's what I do - I carry a pint of Sea Foam with me on the boat. When I replace the Fuel Filter, I fill it with the 16 oz. of Sea Foam. Then prime it with the bulb and run the thing at idel for 10 minutes. If you're changing the F. Filter as part of your maintenance routine, then it is also time to do a de-carb. One easy way of doing this is with the above method which introduces a heavily Sea Foamed flow of gas through your injectors and engine - the insides of which will be clean as a whistle after you burn that mixture (preferably at idle). Then, once all this is over, it's not a bad time to replace, or at least clean, your spark plugs as they will get dirty from the de-carb procedure. Make sense?