Carb recommendations

[Taylorman]

I have come to the conclusion that the 850 carb i have on my boat is to big. Im in the market for a 750. Im looking at Holleys but also looking at others holleys put together by aftermarket companies. Im looking at Proform and Quick Fuel and the holley hp 82751 which is less that the hp 80528. Im not looking to spend a ton on it. The proform is $500 which is less than Holley Hp carbs. The quick fuel is $562 and the hp 82751 is $500. Any suggestion?

[FASTRAT]

Taylor...
i dont re-call the sz of ur motor?...the 850cfm carb is a good choice for a eng 454+...i think tinkering around with it...jets, pv, squirters, air cleaner assy (scoop..V-stack) etc...u can get it to run rite!...i have run 1 on my mild BBC 427 with n/p...think about it before u jump to any conclusions...just my .02 cents
fastrat

[Taylorman]

Its a 462, 5000 rpms.

[SmokinLowriderSS]

Although I agree that the 850 is bigger than optimum for ya, it should be close enough if it is tuned right. I would suspect it of being a little too rich, perhaps drop a couple sizes below original? What accel pumps are on both ends (assuming a 4150 style mech seccondary)? I am running a flawless 700 on a 454 but have the small pump on the pris and the large pump on the secs (10cc & 50cc). The dif is obvious as to pump diaphram housing depth. It MAY need the big pumps on both ends to cover an idle to wide open slam that mine does staggered. That's a big hole to fill.

[YeLLowBoaT]

with 100%VE you need ~ 680 cfm. so a 700 or a 750 would be good choices.

[GofastRacer]

A 750 would be more than adequate for that, here's a formula!..
Carb Sizing! (http://www.mortec.com/carbtip1.htm)

[Fool Throttle]

Would you want to sell yours? I really need a 750 or 850 Holley Carb before the weekend! anyone let me know. jason@0to60performance.com
Jay

[Lavey Huffer]

Barry Grant Mighty Marine Demon was my choice

[Terminal Velocity]

My question is why do you feel it is too big? Are you having a hesitation off idle, while cruising and you don't go full throttle but go an extra 1/4 is there a hesitation? I understand VE and everything for a giving equation but you CAN get a bigger carb to work. And let's face it $500 for another carb will buy a whole lot of gas.
What jets are you running?
What squirters are you running?
What Power Valve are you running?
What Accelerator's are you running? (30cc or 50cc)
What vaccum reading do you have at the base of the carb at idle in gear and cruise RPM.
What is your timing set at? initial, when is it full advance(rpm's)
When checking your vaccum while someone is driving the boat at idle adjust the idle mixture screws in and out until you acheive the highest vaccum reading when you get this number your power valve should be 1-2 sizes below this. i.e. 9.5-10 vaccum 7.5-8.5 Power valve, after you do this you will need to re-adjust your idle mixture screws.
These numbers would greatly help in possibly saving you $500 in a new carb with only maybe $40 in parts.
My suggestions for your carb without knowing too much of the above info would be to put 35 squirters (without the little tubes) around a 7.5-8.5 PV, as for jets well that's going to take a jet kit and some time at the lake checking plugs.
There's a lot of stuff here but even if you do get another carb it will not be adjusted correctly until you do all of the above items.