5.7 mercruiser losing power and backfire through the carb

[Brice1310]

I have a 98 bayliner 2050ss that will run fine at high speeds and low speeds. Sometimes I can run for a few hours fine and then all of a sudden I will start losing power and the boat will stall out and I have to back off the throttle but when I give some throttle the engine will start backfiring through the carb. I can let it sit for 10 minuets or so and crank back up and pull a tube with no problems but out of no where the boat will stall and backfire.

 

[makomark]

sounds like the fuel tank has crud in it and after running for a while, the crud accumulates on the screen of the pickup tube.....