Rejet 2 barrel or buy 4 barrel carb

deer9620

Seaman Apprentice
Joined
Jun 4, 2012
Messages
32
I have a 2006 Chaparral 216 Sunesta. I purchased the boat with a cracked 305 engine. I have replaced the engine with a brand new crate 5.7 vortec. All ignition components have been replaced also. This is my second season with the boat. Boat runs great, however I really can't get Rpms above 4300 or so. I replaced my prop with a new Volvo prop. The only difference it made was my RPMs increased only when the water is calm. Really feels that the boat is starving for fuel at top end. Plus I really can use a little more punch out of the holeshot for skiers. Anybody ever rejet a Holley 2 Barrel? Any difference in performance? Should I play around with the 2 barrel, or just stop playing games and go to four barrel? Not looking to save gas, I just know carbs aren't cheap. Looking at a new edelbrock 600. Opinions? Forgot to add this. It doesn't need a new intake manifold for 4 barrel swap. It has the adapter plate on it already.
 
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gbeltran

Petty Officer 1st Class
Joined
Jul 12, 2009
Messages
283
A rejet, probably wont make a difference.The 305 carb is probably just too small for the 350. I don't know what the CFM rating of that carb is, but a quick search with the R- or List number on the choke horn will tell. If it's 500 cfm then rejetting will probably help, but I'd look at the plugs first. Is it running rich? Lean? If it's 300-350 CFM then I'd move on to a bigger carb. Rejet will only allow more/less air/fuel ratio, not more air which it sounds like you are wanting/needing. I'd go with the 4 barrel, but that's me.
 
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Bondo

Moderator
Staff member
Joined
Apr 17, 2002
Messages
71,095
Not looking to save gas, I just know carbs aren't cheap. Looking at a new edelbrock 600. Opinions? Forgot to add this. It doesn't need a new intake manifold for 4 barrel swap. It has the adapter plate on it already.

Ayuh,..... I, no doubt, would have Already done that,...... ;)
 

gm280

Supreme Mariner
Joined
Jun 26, 2011
Messages
14,605
deer9620, if you do move to a four barrel, I would also go to a four barrel intake. A nice aluminum model designed for your engine and marine usage. Other wise the 2 barrel setup with an adapter plate is merely cutting off the true flow for the four barrel. But that is just my opinion...
 

gbeltran

Petty Officer 1st Class
Joined
Jul 12, 2009
Messages
283
deer9620, if you do move to a four barrel, I would also go to a four barrel intake. A nice aluminum model designed for your engine and marine usage. Other wise the 2 barrel setup with an adapter plate is merely cutting off the true flow for the four barrel. But that is just my opinion...
They already use a 4bbl intake with an adapter for the 2bbl, so manifold should be good to go. They did the same thing when they were using TBI injection, 4bbl intake with adapter......
 
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