Help me set up my new edelbrock 1409

Rugglesworth · Tuesday at 10:19 AM

Hi there, I recently bought a Sea Ray Ski Ray tournament inboard ski boat that came with an automotive carb that was too big (800cfm). I bought a brand new edelbrock 1409 carb for it. I want this thing purring and trouble free for the summer. I plan to ski, wakeboard and surf my boys this summer.

As you can see there are 2 spacers on there. I want to get a consensus on whether I should just bolt the new carb on or if I should remove one or both. Originally research from another forum member shows it came with a wedge spacer and a webber carb. So should I just bolt on the new carb and see she runs? Should it run straight out of the box and just need some fine tuning? I'm worried about losing low end torque.

I've never replaced and tuned a new carb before but I am very mechanically inclined so I just need some guidance explained to me like I'm 10 years old.

Rugglesworth · Tuesday at 11:43 AM

The motor is a mercruiser 350 ski mag, with a replaced block

Scott06 · Tuesday at 12:12 PM

A spacer can help with midrange by adding plenum volume but in this case, unless the PO was using them to adapt from a speadbore manifold to square bore carb I'd take them off.

Setting the carb up should be pretty easy as that should run good on a 5.7 out of the box. Start wit the idle mix screws 1.5 turns out, get it up and idling set ignition timing then fine tune the idle mix screws. From 1.5 out I usually run them in until it stumbles then run them out until it stumbles and leave them in the middle of those two extremes.

Only issue i had is the accelerator pump linkage had some slop that was causing a bog. You will will need a vacuum cup to cap the mechanical fuel pump overflow nipple (on airhorn) as I assume you have a electric pump

This book will help a bit.

https://www.edelbrock.com/media/wysiwyg/documents/carb-owners-manual.pdf

Rugglesworth · Tuesday at 12:19 PM

Scott06 said:
A spacer can help with midrange by adding plenum volume but in this case, unless the PO was using them to adapt from a speadbore manifold to square bore carb I'd take them off.

Setting the carb up should be pretty easy as that should run good on a 5.7 out of the box. Start wit the idle mix screws 1.5 turns out, get it up and idling set ignition timing then fine tune the idle mix screws. From 1.5 out I usually run them in until it stumbles then run them out until it stumbles and leave them in the middle of those two extremes.

Only issue i had is the accelerator pump linkage had some slop that was causing a bog. You will will need a vacuum cup to cap the mechanical fuel pump overflow nipple (on airhorn) as I assume you have a electric pump

This book will help a bit.

https://www.edelbrock.com/media/wysiwyg/documents/carb-owners-manual.pdf

Thanks for the info so far, it has a mechanical fuel pump with the yellow fuel line that should be connected to the carb nipple. The PO just had the open yellow line laying on the intake which is insane.

Scott06 · Tuesday at 12:26 PM

Rugglesworth said:
Thanks for the info so far, it has a mechanical fuel pump with the yellow fuel line that should be connected to the carb nipple. The PO just had the open yellow line laying on the intake which is insane.

Its only insane when the fuel pump diaphragm ruptures.... I'm a safety is for sissies kind of guy but some things make sense.

If you end up needing to rejet it the eddy book has some charts that help figure out which way to go.

Rugglesworth · Tuesday at 1:02 PM

Scott06 said:
Its only insane when the fuel pump diaphragm ruptures.... I'm a safety is for sissies kind of guy but some things make sense.

If you end up needing to rejet it the eddy book has some charts that help figure out which way to go.

sounds good. Hopefully I don't need to re jet as everyone so far has said it's as close to a bolt on as you can get. I may get to it after work tonight depending on the weather

Bondo · Tuesday at 1:23 PM

Ayuh,..... What is that monstruous exhaust thingy on the back of the motor, instead of a y-pipe,..??

Personally, I'd ditch the spacers, myself,....

That edlebrock book Scott posted is the Bible, for the AFB carbs, it answers questions you don't even think to ask,....
Years ago, when I dropped the 4.3LX into my fishin' barge, the Merc tune was too rich, made yer eyes water, especially with a tailwind, trolling,....
I bought the tuning "Kit" with abunch of jets, needles, 'n springs,....
A change of needles, 'n springs turned it into a real sweetheart,....

Scott06 · Tuesday at 1:32 PM

Bondo said:
Ayuh,..... What is that monstruous exhaust thingy on the back of the motor, instead of a y-pipe,..??

This is direct drive/inboard ski boat so they typically have an exhaust like that not sure if it is a muffler before going under the water at the transom

Rugglesworth · Tuesday at 1:37 PM

Bondo said:
Ayuh,..... What is that monstruous exhaust thingy on the back of the motor, instead of a y-pipe,..??

Personally, I'd ditch the spacers, myself,....

That edlebrock book Scott posted is the Bible, for the AFB carbs, it answers questions you don't even think to ask,....
Years ago, when I dropped the 4.3LX into my fishin' barge, the Merc tune was too rich, made yer eyes water, especially with a tailwind, trolling,....
I bought the tuning "Kit" with abunch of jets, needles, 'n springs,....
A change of needles, 'n springs turned it into a real sweetheart,....

The monstrous exhaust thingy is a muffler dual into single exhaust out the back. Not sure why they designed it for a single exhaust.

As far as the spacers being taken off I'll have to find the stock size carb mounting studs. Also I am a little concerned about not having the stock wedge spacer that originally came with the motor as the direct drives tend to be tilted quite a bit.

Scott06 · Tuesday at 1:43 PM

Rugglesworth said:
The monstrous exhaust thingy is a muffler dual into single exhaust out the back. Not sure why they designed it for a single exhaust.

As far as the spacers being taken off I'll have to find the stock size carb mounting studs. Also I am a little concerned about not having the stock wedge spacer that originally came with the motor as the direct drives tend to be tilted quite a bit.

probably easier to snake one exhaust hose below the floor than 2

summit racing has wedges as you dont want to price the OEM one ..
you can probably get studs at a local auto parts store, or old time hardware store . I think they are 5/16 coarse. Might be worth cutting down what you have until you get it situated how you want it.

Rugglesworth · Tuesday at 2:05 PM

Scott06 said:
probably easier to snake one exhaust hose below the floor than 2

summit racing has wedges as you dont want to price the OEM one ..
you can probably get studs at a local auto parts store, or old time hardware store . I think they are 5/16 coarse. Might be worth cutting down what you have until you get it situated how you want it.

I saw the wedges on there. I've read online that a 12 degree wedge is the way to go. They are crazy expensive. Like $300usd or $15cad for a piece of aluminum. I found a 5 degree one locally for $100 but not sure that would do the trick. I'd like to know what degree the stock one (Mercury 821109T) was.

Bondo · Tuesday at 2:15 PM

Rugglesworth said:
I saw the wedges on there. I've read online that a 12 degree wedge is the way to go. They are crazy expensive. Like $300usd or $15cad for a piece of aluminum. I found a 5 degree one locally for $100 but not sure that would do the trick. I'd like to know what degree the stock one (Mercury 821109T) was.

Ayuh,...... Adjust yer trailer jack to where the boat normally sits in the water, then measure what you need,.....
The tilt of the wedge is so the float bowls are at the proper angle,....

Rugglesworth · Tuesday at 5:12 PM

Scott06 said:
A spacer can help with midrange by adding plenum volume but in this case, unless the PO was using them to adapt from a speadbore manifold to square bore carb I'd take them off.

Setting the carb up should be pretty easy as that should run good on a 5.7 out of the box. Start wit the idle mix screws 1.5 turns out, get it up and idling set ignition timing then fine tune the idle mix screws. From 1.5 out I usually run them in until it stumbles then run them out until it stumbles and leave them in the middle of those two extremes.

Only issue i had is the accelerator pump linkage had some slop that was causing a bog. You will will need a vacuum cup to cap the mechanical fuel pump overflow nipple (on airhorn) as I assume you have a electric pump

This book will help a bit.

https://www.edelbrock.com/media/wysiwyg/documents/carb-owners-manual.pdf

Ok check these pics out. These aren't open spacers. They're both aluminum. Both have 4 holes not just an open plenum and it looks like the small spacer actually directs fuel to the two front barrels. Maybe I can just use the small aluminum one instead of worrying about the wedge as it directs flow? Or both or just the big one? I've heard these types of spacers help more than just an open plenum

Earl Cordova · Tuesday at 5:42 PM

Don't even waste time taking pictures of the spacers.
Just throw them out. The person that set up that layout is a total hack.

Rugglesworth · Tuesday at 6:01 PM

Earl Cordova said:
Don't even waste time taking pictures of the spacers.
Just throw them out. The person that set up that layout is a total hack.

So even the small aluminum one that directs flow forward is worse than having no wedge and just a straight carb on there? Definitely know the guy is a hack. You should or shouldn't see the stereo wiring I'm sorting out as well

Scott06 · Tuesday at 6:40 PM

Rugglesworth said:
Ok check these pics out. These aren't open spacers. They're both aluminum. Both have 4 holes not just an open plenum and it looks like the small spacer actually directs fuel to the two front barrels. Maybe I can just use the small aluminum one instead of worrying about the wedge as it directs flow? Or both or just the big one? I've heard these types of spacers help more than just an open plenum

Without the spacers what does the intake carb flange look like

Rugglesworth · Tuesday at 6:57 PM

Scott06 said:
Without the spacers what does the intake carb flange look like

It's a 2 plane intake. 2 large holes on either side

Scott06 · Tuesday at 7:06 PM

Rugglesworth said:
It's a 2 plane intake. 2 large holes on either side

Spread bore or square bore google it you will see the diff. If spead bore you may need an adapter to line up with your square bore carb

Bondo · 2025-04-23T02:54:55-0600

Scott06 said:
Spread bore or square bore google it you will see the diff. If spead bore you may need an adapter to line up with your square bore carb

Ayuh,..... The 1409 will fit either pattern,.....

Scott Danforth · 2025-04-23T04:04:15-0600

one is a divergent spacer for a square bore carb. small holes at carb transitioning to the big oval holes on the manifold.

the other is a conversion spacer for the spread bore to square bore.

Not sure you need both

Help me set up my new edelbrock 1409

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