I have a 2004 40hp 2 stroke. It is idling fine but when I put it in the water and give it throttle it runs real rough and then falls on its face. I checked the carbs and they look to be clean. Not sure where to start looking next?
Check compression, spark, timing, and then fuel.
How did you check the carbs. they need to be disassembled completely and cleaned with carb cleaned and compressed air. And then do a link and sync on them once reinstalled