I'm dealing with a set of Holley 4011's that I think are worthless. They are the non removeable fuel bowl dual feed carbs. They have a top plate that removes to access the float. They seem to be very problematic as I cannot dial them in at all. They are vacuum secondaries and electric choke. I need a hand with what I should replace them with, and where to find a good used set? They are on twin mercruiser 300 tempest motors. I think they are 650 cfm.

Any ideas on a good economical replacement??

First what kind of intakes are they On? I would call Holley tech and see what converts with your intake. Do not go cheap on the brand of carb. It is what makes your motor go. Cheap ones typically fall apart and you go less.

Those would be a spread bore type carb. Primaries are small and the secondaries are large. The original carb merc put on the 300 Tempest was the Rochester Quadrajet. 4MV 1347-7498A6 (17059280) You can get reman ones here for $199.95. They do however have a $40 core charge also.
http://www.nationalcarburetors.com/m...rochester.aspx

Holley also makes another model 650 spreadbore, the marine 4175 which has the seperate removable bowls but don't know of used ones and their pretty high. Those 4011's you have now are close to $500 new.

Mike these are exactly what I have and you cant beat the bang for the buck. Seriously...before considering buying mine get this deal...great people to deal with and they come set up to run out of the box. To get you up and running you can buy 2 of these for what you will pay for 1 Marine Holley...if you can find one for $400.

I had the 4011 and had bad luck with them as well. If you want something good out of the box I would go with the edelbrock 1409. They work great on my twin 350 application. No tuning really required except for the idle.

+1 on 1409 Edelbrock

Yea, I've had it with these damn carbs. I had to lower the float bowl as far as I could and it kind of idles after replacing all the needles and cleaning the crud out of them. That was after multiple bouts of flaming carbs in my driveway.

I got it on the water and started one of the engines and the damn thing flamed up again (stuck float, or needle)....It scared the BAH-JESUS out of me, I snuffed it out and immedielty pulled the boat in. Haven't played with it since (3 months)

I guess I'm not looking for a set of Rochester's or Edelbrock 1409's.

Did I mention fire scares the chit out of me???

a lot of people don't like q-jets. the carter AFB (aka Edelbrock) is very easy to deal with. i still have 4010 Holleys on the Hatteras, but it never goes anywhere anyway...

those things are door stop material...on normal apps, hard to beat the 1409 edelbrocks...maybe not the best all out H/P but great everyday carbs

Right now I'm leaning towards a pair of these for my rig:

http://sdparts.com/details/holley-pe...ducts/h0-4777c

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Lot of bang for the buck. I have run these before on boats and cars with good results. The description text is in error in stating that these are "vacuum secondary"

Personally, I think the only thing better than a Holley Mechanical Secondary Carburetor on a boat is MPI. They are good performers and economical in the sense that the operator controls the secondary opening.

I know they aren't marine carburetors but I have never experienced any issues with them. If bowl flooding is of concern you can always add a set of these:

http://www.jegs.com/i/Holley/510/14R...oductId=743692

...and suddenly you have marine versions.