Mercruiser 120 bogs when throttle is opened up. I have read about a screen that could be clogged which restricts the flow of fuel to the carburetor. The engine idles perfectly but bogs severely. Just rebuilt the carburetor and replaced all electronics and fuel filters. I didn't look into the fuel tank as it is buried under the floor. I can cut a "door" into the floor and place a hinge on it to provide access to the tank. My question is, is there a screen in the fuel tank that could be clogged which is restricting flow to the fuel line? If so, where would the screen be and how can I clean it?