Mercruiser 4.3L 190 HP Carb/Manifold Intake Upgrade

[m4keyourself]

Hey all!

I'm considering upgrading the carburetor on my Mercruiser 2001 Glastron SX 175 (Alpha One, 4.3L, 190HP) from a 2BBL to a 4BBL. I believe I'll need to upgrade the manifold intake as well, since it's only fitted for a 2BBL (ID: GM 12552422)

I'm wondering where I can find a 4BBL manifold that will fit my engine? Finding an exact replacement 2BBL is easy enough to find, but I'm not quite sure how I go about finding a 4BBL that will fit my engine without having a product ID.

I've attached a few pictures - one of the manifold intake model number, one of the carb, and the "vortec" label.

Any advice would be awesome, thanks!

 

[Scott Danforth]

just search the forums. the information is out there in the threads

edelbrock marine intake (with the bronze water passages) and edelbrock 1409 carb. you can buy them at summit racing

you also need a different spark arrestor

 

[Scott06]

These guys have both cast iron and edlebrock marine ones. You need one for vortec heads 96& up. https://www.michiganmotorz.com/products/marine-parts-accessories/intake-manifolds/v6-4-3l

they also have the edlebrock 1409, you will find threads on here on jetting needs for that carb on a 4.3.
throttle bracket and return spring 16& 12 in this drawing will allow for a clean installation http://www.marineengine.com/parts/m...p/carburetor-and-throttle-linkage-four-barrel

 

[m4keyourself]

Awesome, thanks guys! I've had my boat for 5 years now and been doing some tinkering around with it. You all have been a lot of help, thanks for the knowledge and assistance.

 

[m4keyourself]

These guys have both cast iron and edlebrock marine ones. You need one for vortec heads 96& up. https://www.michiganmotorz.com/products/marine-parts-accessories/intake-manifolds/v6-4-3l

they also have the edlebrock 1409, you will find threads on here on jetting needs for that carb on a 4.3.
throttle bracket and return spring 16& 12 in this drawing will allow for a clean installation http://www.marineengine.com/parts/m...p/carburetor-and-throttle-linkage-four-barrel

This is exactly what I was looking for - thank you!

 

[Scott06]

This is exactly what I was looking for - thank you!

Hers a thread on where carb tuning ended up https://forums.iboats.com/threads/stumbling-edelbrock-1409-4-3l-v6.670697/page-2

he is still active on this forum if you need more assistance

 

[m4keyourself]

Hers a thread on where carb tuning ended up https://forums.iboats.com/threads/stumbling-edelbrock-1409-4-3l-v6.670697/page-2

he is still active on this forum if you need more assistance

Great, thanks for tracking that down for me. That'll definitely save a lot of time and hassle. Rick helped me out on another post before and he knows his stuff. Much appreciated

 

[nola mike]

You'll also a new throttle bracket for the 4bbl. And Rick and I ended up in much different places with the jetting.

 

[m4keyourself]

You'll also a new throttle bracket for the 4bbl. And Rick and I ended up in much different places with the jetting.

That's good to know, thanks for sharing. I know there's a lot of different factors when tuning the carb, so I'll roll with it. I'm sure I'll have to make adjustments, but at least it's a good starting point.

 

[MichaelBC]

I can also only recommend not buy the V6 conversion kit from Edlebrock. I have done that and the engine didn't run really well. With Ricks setup I am absolutely happy now.

Engine rpm is not stable below 2000 rpm

Hallo, yesterday I took my boat with the new engine out on the mediteranian see for the first time. The engine starts immediately when I turn the key and runs nicely. I did set the timing and idle speed in setup mode of the ECU. When I accelarate a little and reach about 1300 rpm the...

forums.iboats.com

I have bought the Edelbrock manifold. For this you need a selection of plugs to close the holes that you don't need. Don't forget the one at the back underneath the carb.

 

[wshekar]

Are the performance gains noticeable? I wonder if the money versus performance works out.

 

[m4keyourself]

I can also only recommend not buy the V6 conversion kit from Edlebrock. I have done that and the engine didn't run really well. With Ricks setup I am absolutely happy now.

Engine rpm is not stable below 2000 rpm

Hallo, yesterday I took my boat with the new engine out on the mediteranian see for the first time. The engine starts immediately when I turn the key and runs nicely. I did set the timing and idle speed in setup mode of the ECU. When I accelarate a little and reach about 1300 rpm the...

forums.iboats.com

I have bought the Edelbrock manifold. For this you need a selection of plugs to close the holes that you don't need. Don't forget the one at the back underneath the carb.

Got it, thanks Michael! I'll be sure to pick up some plugs. Looks like they're not too expensive.

 

[MichaelBC]

Are the performance gains noticeable? I wonder if the money versus performance works out.

This question I can not answer because I swapped from an old non Vortec engine with Thunderbolt IV ignition and 4 bbl carburetor to a brand new Vortec engine with Edelbrock carb and intake bridge and Thunderbolt V ignition. With this setup the performance increase is very noticable.

With the 23P four blade propeller I did reach a maximum of 4300 rpm with the old engine. The news on turns to 4700 rpm easily. The max speed also increased by 10 km/h.

 

[m4keyourself]

Hey guys - back at it with another question. I hope you don't mind. I've been doing some research and it seems like ensuring you have reliable, good quality fuel pressure regulator if you're upgrading to an expensive carb. With my 2001 Glastron SX 175 190HP 4.3L engine, I *believe* my fuel pressure is regulated by the electric fuel pump - so it's a fuel pump/pressure regulator combo. Is this the case? If so, would it be worth swapping it out for something aftermarket? Thanks!

 

[Scott06]

Hey guys - back at it with another question. I hope you don't mind. I've been doing some research and it seems like ensuring you have reliable, good quality fuel pressure regulator if you're upgrading to an expensive carb. With my 2001 Glastron SX 175 190HP 4.3L engine, I *believe* my fuel pressure is regulated by the electric fuel pump - so it's a fuel pump/pressure regulator combo. Is this the case? If so, would it be worth swapping it out for something aftermarket? Thanks!

I dont use a pressure regulator in front of my 1409 no issues, just the stock merc low pressure pump

 

[Rick Stephens]

Just the Airtex pump for me.

 

[m4keyourself]

Awesome thanks guys!

 

[Scott Danforth]

FYI, Carter is airtex.

Carter has been the OEM for years.

no need for a regulator.

been using the carter variants in both marine and auto and diesel for years