Hi, I have a 1979 Mercury V-150.The trouble starts everytime I start the engine in the mornings and I hammer the throttle to w-o-t,it starts bogging real bad and has no power.After keeping it at w-o-t for an average of 2-3 minutes,it will plane out and run great pretty much the rest of the day,but if I fish a couple of hours and go to crank it,it's hard to start and it begins that bogging again.I've replaced the plugs,wires,fuel filter,fuel lines,cleaned out the tanks,rebuilt all 3 carbs.The ball on the fuel line isn't leaking down,it's firing on all cylinders,and it has good compression.I've owned it for about 6 months,and it has done this everytime I have taken it out.I recently replaced the reed valves and overhauled the powerhead,but still no change.I'm at my whits end and would appreciate any guidance to help solve this nightmare.Thanks

Sounds like a stuck carb float 2 me.
With engine off, squeeze primer bulb and see
If you have gas leaking outa front of a carb.
Look at all check valves starting at primer bulb
and into the 3 carbs.
The 150 is a thirsty girl and don't take kindly
to fuel problems...
Good luck, she's a screaming engine!

I would check the bleeder check valves to see if they are funtional. They are located on the manifold and have the black hoses running to them.

TMD