1996 searay 215 express cruiser. 350 ci

Ed Harris

Petty Officer 1st Class
Joined
Jan 7, 2016
Messages
217
original engine came with a 2 barrel carb. Was wondering if it’s worth upgrading it to a 4 barrel? The 2 bbl gets it up but the 4 bbl in theory should make it better
 

kmarine

Chief Petty Officer
Joined
Nov 5, 2010
Messages
591
MAYBE, My drag racing friend will differ with you. If you have a large enough two barrel carb with enough cfm You can out perform a 4 barrel on acceleration. An early 350 throttle body efi is essentially a two barrel carb with fuel injectors replacing the jets. You may need to change over the manifold to go to a 4 barrell carb. Most likely your carb has enough cfm at 5000 rpm to efficiently power your boat. if you are needing more power you may need more than a carb to get where you want to be. It depends on how you like to run your boat. You can do more with props than most people believe to out perform your current setup. a 4 and 5 blade prop can make a bigger difference.
 

Bondo

Moderator
Staff member
Joined
Apr 17, 2002
Messages
71,095
original engine came with a 2 barrel carb. Was wondering if it’s worth upgrading it to a 4 barrel? The 2 bbl gets it up but the 4 bbl in theory should make it better

Ayuh,..... It's worth 'bout 25 hp, mostly at top end,.....

I suggest an edelbrock 1409, a carbon copy of the Merc/ weber AFB still used by Mercruiser,....
 

Rick Stephens

Admiral
Joined
Aug 13, 2013
Messages
6,118
Only reason I like the 4 barrel on my 4.3 is with smaller primaries than the 2 barrel it is more efficient and 'snappier' if all I use is the primaries. I notice a big increase in fuel usage, and noise, when opening up the secondaries with marginal increase in top end performance. Nature of the beast, I guess. You have more motor, so the 4 barrel can improve performance a lot more.
 

Ed Harris

Petty Officer 1st Class
Joined
Jan 7, 2016
Messages
217
Tks for the replies. Have been reading a lot of different opinions on the web. Will try props and play with my tabs. Boat is new to me only 1 week and so far 2 times out on the water. A carb rebuild is in the future before I do anything because on a cold crank the motor will rev up and down until it gets warm
 
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