EZ tell me if I'm wrong here, but I rebuilt the carb and put it on. Boat runs substantially richer than before. So I pull and re-adjust floats. No change. Idle screws, no change. Nothing makes a difference. I broke down and ordered a reman from national carburetors. Any one have any other thoughts?

something would have to be done wrong if rebuild and now way rich, bad power valve(had that happen recently out of the package and were holley) wrong gaskets blocking a passage, leaking needle & seat...or excessive fuel pressure...also make sure ignition is ok...on some cases some ignition issues seem like a carb issue...points closed up for one thing..

The powervalve is new and installed correctly. And the carb was running rich prior to the rebuild. Now it is just worse. I've heard of the powervalve's being damaged by a backfire, but my carb has the check ball, so even though it back fired on initial start up, I'm inclined to believe I'm alright. Part of my problem is that the floats refuse to set properly. The motor is angled down towards the rear, so naturally the back of the carb is lower. I've adjusted the floats up and down, and messed with A/F screws and idle mix to no avail

Forgot to mention, my floats don't match. One is very old school metal and one is newer plastic. Also the fuel tube that runs between the bowls is slightly bent. I doubt it matters, but figured it bears mentioning.

i recomend checking your ignition system,if it is weak it cant fire the fuel ,that can be confused for carb problems.

I've got new plugs, wires, and coil. The dizzy is a mallory and maybe 3yrs old...

if you pull the float bowl and look at the power valve dia side, should be dry, if it's wet or damp it's leaking, or if the well area behind the metering block where the power valve gets it's vacuum signal is wet, it's leaking, makes no difference how old/new your dist is, new parts fail to...pull site plugs off side see where they are(not running) fuel should be below hole edge, no concerns of the floats as long as they float...

I did the site screws. One is good, other is pouring fuel

You should be able to set your float levels "to the sight port" by adjusting the float screw on top of the bowls. If you cannot get one to stop pouring fuel regardless of the setting, then you have a bent float tab or the needle is not installed correctly. You keep saying fuel pours out of the level port, and you keep saying it runs rich.

When you rebuilt the carb, did you not check the float tab and make sure the float would fully close the needle before hitting the top of its travel?
There's a lot more to a carb rebuild than throwing in some new gaskets and powervalve. You should be cleaning all passages, looking for gasket mismatches, looking for malfunction of the float/needle mechanism, realigning your butterflies, etc.

MC

also the float may not float. all the adjusting in the world won't help a float full of gas. while you are at it, do a compression test.