1995 mercruiser starting problems

"Hello, I have a 1995 Baja wit

"Hello, I have a 1995 Baja with a 7.4L mercruiser. I have had one heck of a time to get it started after hauling it down the road. It seems to be fludded when I get to the ramp. This has been an ongoing problem for years. I reciently have done some things thinking it would help. I completely drained all of the fuel. Found some water. Replaced fuel filter. I have a gas vent below the gas fill. I left the cap loose so pressure would not build up in the tank. I installed a fuel shutoff valve right before the fuel pump. I had the carbureator rebuilt. New spark plugs. The last time I took it to the lake I ran the carb out of gas before I went. Got to the launch ramp, boat hesitated for a min acting like it was fludded then ran great all day. Pulled it out of the lake and shut off the fuel and tried to start it here at home and fludded again. Do you guys have any suggestions or answers. There is nothing more embariseing at the launch ramp with black smoke comeing out of the engine fludded.
Thanks Bobby"

"Just a guess, even though the

"Just a guess, even though the carb was rebiult your choke may not be adjusted or working correctly. Other possibitlity is the floats were not set correctly when rebiult."

"The butterfly valve is full o

"The butterfly valve is full open when hot and open slightly when cold. I am not sure on the floats. It wants to backfire now after I got it unfludded, do you think I have a fouled spark plug?"

"Perhaps it's time to repl

"Perhaps it's time to replace some worn ignition parts; cap, rotor, wires...plugs are fouled w/soot--replace them."