Quadrajet help...anybody?

I am having problems with my quadrajet on the 78 cuddy.

I purchased a rebuild carb and installed last year. Boat has ran well up until a week or so ago. I was running in some rought water, 3 to 5's, and when I entered the harbor and idled down the motor died. It started right back up and ran rough. I revved it up in netural and it came out of it. Now this idle problem has been happening more and more, and finally the motor died and I was unable to keep it running. After looking under the flame arrestor, fuel was pouring into the primary fuel chamber with the motor stalled. I shut off the fuel supply and dried the primary out. Restarted the motor and was able to just get it back to the dock. Docking this 23' boat without power was not fun.

I am guessing that somthing must be causing the needle not to seat? I have never torn a carburator like this down and not sure where to start. Any ideas?

Brian, Thanks for all your help over the phone! Hope you avoided the storm.

After removing the air horn, I found alot of white looking scale in the bottom of the fuel inlet chamber. This must have been getting stirred up and fouling the needle and seat. I cleaned it all out the best I could and reassembled. Started motor up on garden hose and seems to run fine. Hopefully get to water test it this week.

I purchased this carb from an online rebuilder and it seems they did a poor job rebuilding. There was no "white scale" on the inlet filter only a slight bit of rust scale. The rest of the scale came from inside the carb. This carb had only been on the boat for little over a year after the rebuild and it was stored with fuel stabalizer so I don't think that I was the cause of the scaling. I think that it was not cleaned properly before rebuilding?

Gasohol is a son of a gun today with carbs. This white scaly substance is becoming pretty common place. I had a similar problem with the edelbrock on my 302 after proper storage this year, blamed it on the fact that it wasnt a holley carb and resolved to throw it in the garbage and rebuild one of the holleys on the shelf and dump it in. However the same scale has now shown up in two of my 60's era mercury outboards this summer, talk about a pia 3 carbs to remove clean and then resync, either I had a bad batch of stabil around winterization time or they need to reformulate the stabil for the ethanol rich crap being passed off as gas today.

use premium gas and not the cheap stuff.

No ethanol in premium ??? Do you run Sea-foam in every tank?