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Mercarb to Edelbrock 1409 quesitons

Naptown_NR

New member
Hi all. I have a cracked block so I am about to re-power my SeaRay 185, it is 1998 Mercruiser 4.3 Gen+ block 090. Long block is on its way and I am now considering going from the 2bl Mercarb and stock intake manifold to the Edelbrock 1409 carb and 2519 intake manifold.

I know I will need the 1485 calibration kit. My question is what else do I need?

1. Throttle linkage different? -- Do I need to order the Mercruiser 4bl throttle linkage? Are there other options?
2. Fuel connection different location? -- Marine application requires hardline to electric fuel pump? Is only option to bend/flare my own? Can I use Edelbrock fuel line kit then go rubber to the electric fuel pump?
3. Heat Insulating gasket? My 2bl has a plastic block spacer, should I also install the Heat insulator 9266?
4. New center stud? 4.5"?

OR

Stop all this nonsense, keep the stock intake and carb and be happy keeping $800+ bucks in my pocket?

Thanks everyone!
 
I would keep the 2 barrel. You will probably never open the secondaries on the 4 barrel even at WOT. That, and by the time you detune it to run on the 6, you're pretty much inside the performance envelope of the original carb. Marine engines like smaller carbs.
It's always like limp noodle sound when you open the hatch on one of those big old 70's era Connies and see two massive big blocks with weeny two barrel carbs. But that's all they need.
 
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out of curiosity... what do you think you will be getting for your $800 + labor investment?

Thanks for responding sandkicker. Honestly, I am not sure. Better hole shot? Little more top end? I think I am in a situation where it is easy to start looking at little tweaks as I am about to drop a new engine in. It's hard to keep the finger off the mouse and click around looking at other things I can do to the engine while I wait for it to arrive! I have to remind myself, this ins't my dream boat I am dealing with here, it will run just fine stock, will be plenty fun, and the cheaper I can run it, all the better!
 
If you are in salty or brackish waters you cannot run automotive type ally intake. It will corrode/electrolysize from the inside and you won’t know until you start having overheating problems...you can run cast iron no prob.
 
Find an on-line interactive engine CFM calculator.
Plug in your cu.in. data and the cruising RPM.
You will be surprised at how little CFM this engine requires.
 
The Edlebrock will also require YOU to drill and tap its base for the PCV valve.

That two barrel's looking better all the time, right?

Jeff
 
I don't think that engine has a PCV valve ..... just the breather hose, from the rocker box to the flame arrestor....
 
My suggestion would be, use a Holley Marine 2 bbl.

Easy to tune, readily available parts. (accelerator nozzles, accelerator cams, jets, power valves etc...)

Changes are easy and testing can be done very quickly!

With a Marine Holley you can custom tune is for maximum performance without over carbing the engine and having to de-tune the carb.

Holley 2bbl marine carbs was used extensively on OMC I/O's including 4.3 ltr's..
 
As others have mentioned be realistic about what you will be getting ... 10 maybe 15 hp. I did the same when swapping a cracked 4.3 to a 5.0, but I had to buy and intake anyways. The biggest difference I noticed was midrange power and throttle response are great vs any two bbl carbed boat I've had. If you boat in salt water, I'd go for a cast iron intake vs the edelbrock.

The merc throttle bracket 805359T will allow you to bolt the linkage and if you have the slave solenoid on the throttle bracket will mount up perfectly. 24-32817 return spring if your current set up doesn't have it.

On the i boats forum some one posted this calibration for a 1409 on a vortec 4.3 as the kit doesn't seem to work well...

.95 primaries
.92 secondaries
.065x .057 (1461) metering rods with pink 7" step up spring
.043 accelerator pump nozzle

on mine I was able to stretch the fuel line by cutting out the crimped flex hose and replacing with a longer section of marine hose and some good hose clamps. You may not need to modify yours.
 
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