4 to a 2 barrel carb

[sealbot69]

Hey everyone I currently have 1985 3.7 4 cylinder mercruiser engine, I also have a 4.3 v6 mercruiser engine with a cracked block. 3.7 I have all the parts and was a running engine the guy that sold the boat to me screwed the carb up. I was wondering if anyone has any knowledge of a way to use the 4.3’s carb on the 3.7. The only problem is the 3.7 is a 4 barrel and the 4.3 is a 2 so if anyone has any knowledge of an adapter plate or something on the lines of that please let me know.
Best, Connor

 

[matt167]

Simple quadrajet to Rochester 2bbl adapter. Advance auto, summit racing ect. Can get them. Even GM had their own. It's not a marine part but it won't matter

 

[nola mike]

Guessing you'll need to rejet for the 3.7 as well.

 

[Rick Stephens]

Guessing you'll need to rejet for the 3.7 as well.

You jet for airflow, not for engine size or model.

Edit: now that I posted that, rethinking things that would require rejetting. Compression, airflow improvements like from Vortec heads, torque range from stroke.... Guess I should keep my mouth shut. R.

 

[Scott06]

Hey everyone I currently have 1985 3.7 4 cylinder mercruiser engine, I also have a 4.3 v6 mercruiser engine with a cracked block. 3.7 I have all the parts and was a running engine the guy that sold the boat to me screwed the carb up. I was wondering if anyone has any knowledge of a way to use the 4.3’s carb on the 3.7. The only problem is the 3.7 is a 4 barrel and the 4.3 is a 2 so if anyone has any knowledge of an adapter plate or something on the lines of that please let me know.
Best, Connor

As outlined you should be able to get and adapter and adapt the rochester or mercarb two bbl to the manifold, but might require rejetting the carb.

How bad di the PO screw up the carb? If you have a good core I would recommend having it properly rebuilt either locally or someplace like this

Mike's Carburetor Parts

www.carburetor-parts.com

 

[nola mike]

As outlined you should be able to get and adapter and adapt the rochester or mercarb two bbl to the manifold, but might require rejetting the carb.

How bad di the PO screw up the carb? If you have a good core I would recommend having it properly rebuilt either locally or someplace like this

Mike's Carburetor Parts

www.carburetor-parts.com

Or just buy a used carb and sell the one you have. No sense in adding complexity for a downgrade.

 

[jimmbo]

The differences between Carbs is often not just Jets/Metering Rods, but Air Bleeds(not easy to change), Off-Idle Transfer Ports(pretty much impossible to change), Power Enrichment Circuit Calibration and Metering. A Q-Jet is a prime Example, It was used on just about every engine size over 250 cu in, that GM has made since 1965, but you certainly couldn't just pull one off of, say a Buick 455, and expect it run well on a Chevy 283, or a Pontiac 455 for that matter.

 

[Scott Danforth]

Hey everyone I currently have 1985 3.7 4 cylinder mercruiser engine,...... 3.7 I have all the parts and was a running engine the guy that sold the boat to me screwed the carb up. .

unless the guy smashed the carb with a hammer, your best bet is clean the carb on the 3.7. if the carb sat for 3+ months with old fuel in it, the passages will be crudded up anyway.

 

[sealbot69]

Hey everyone I currently have 1985 3.7 4 cylinder mercruiser engine, I also have a 4.3 v6 mercruiser engine with a cracked block. 3.7 I have all the parts and was a running engine the guy that sold the boat to me screwed the carb up. I was wondering if anyone has any knowledge of a way to use the 4.3’s carb on the 3.7. The only problem is the 3.7 is a 4 barrel and the 4.3 is a 2 so if anyone has any knowledge of an adapter plate or something on the lines of that please let me know.
Best, Connor

Thanks everyone to who anwsered. I wish I did have the carb from the 3.7 as when I bought the boat he had thrown it away. If he did have it, it would’ve been just a rebuild and I’m good. I will look into buying a new carb. As well does anyone know of any rebuild kids for the 3.7 that are not that expensive (as I’m trying to keep this boat restoration as cheap as possible) mostly just need gaskets but if anyone has a cheap full rebuild please let me know.
Best -Connor

 

[Scott Danforth]

link in post 5 is the best link on carb parts for the rochester

cheap does not equal good
boat restoration and cheap do not go together.
cheap and 470 do not go together

plenty of the 470 190hp 4-barrel carbs on craigslist and ebay.

here is a deal https://www.ebay.com/itm/144485288530?hash=item21a3fe8a52:g:pLEAAOSw86tiR0re

 

[sealbot69]

link in post 5 is the best link on carb parts for the rochester

cheap does not equal good
boat restoration and cheap do not go together.
cheap and 470 do not go together

plenty of the 470 190hp 4-barrel carbs on craigslist and ebay.

here is a deal https://www.ebay.com/itm/144485288530?hash=item21a3fe8a52:g:pLEAAOSw86tiR0re

I shouldn’t say I’m trying to go cheap I’m just trying to keep the project low cost I know cheap means broken parts after awhile.

 

[Eric 3.7LX Alpha 1]

link in post 5 is the best link on carb parts for the rochester

cheap does not equal good
boat restoration and cheap do not go together.
cheap and 470 do not go together

plenty of the 470 190hp 4-barrel carbs on craigslist and ebay.

here is a deal https://www.ebay.com/itm/144485288530?hash=item21a3fe8a52:g:pLEAAOSw86tiR0re

Nice find on that listing, that is a good price for those parts. Even figuring a rebuild on the carb.

 

[Scott Danforth]

Nice find on that listing, that is a good price for those parts. Even figuring a rebuild on the carb.

considering the carb itself is usually $200, the spark arrestor is $50 and the intake is about $100

 

[achris]

...cheap does not equal good....

Old Chinese proverb...

"Cheap no good, good no cheap"

 

[Scott06]

Thanks everyone to who anwsered. I wish I did have the carb from the 3.7 as when I bought the boat he had thrown it away. If he did have it, it would’ve been just a rebuild and I’m good. I will look into buying a new carb. As well does anyone know of any rebuild kids for the 3.7 that are not that expensive (as I’m trying to keep this boat restoration as cheap as possible) mostly just need gaskets but if anyone has a cheap full rebuild please let me know.
Best -Connor

I buy my carb parts from here https://www.carburetor-parts.com/ all good quality parts. never had an issue with any parts or kits over ten plus years of buying from them for my boats and classic cars.

 

[Dubed]

Where are you located? I have a manifold and carb I pulled off a parts motor.

 

[Scott Danforth]

Where are you located? I have a manifold and carb I pulled off a parts motor.

use the PM's

 

[Dubed]

Let me elaborate, I have a bbl manifold and carb for a 3.7. Probably the linkage also. You can have them if needed

 

[Scott Danforth]

Let me elaborate, I have a bbl manifold and carb for a 3.7. Probably the linkage also. You can have them if needed

again, no buying/selling/swapping in open forums. use the PM's

 

[Dubed]

No problem. I posted that before I knew. Will PM