Carburetor fix or swap?

« **on:** May 04, 2015, 07:00:38 PM »

Looking to rebuild my carb but the other side of me says to buy a new one. What i have now i think is a 780 cfm holley

« **Reply #1 on:** May 04, 2015, 07:03:18 PM »

Sorry guys kinda new to this any input

« **Reply #2 on:** May 04, 2015, 07:37:38 PM »

What you have there is a factory Ford Holley carb from 1971. I couldn't make out the Holley List number to be able to tell you what size it is.

If the carb is not damaged or worn excessively you can rebuild them many times without issues.

« **Reply #3 on:** May 04, 2015, 08:10:19 PM »

If it's a list 6361 is a 650 cfm. Personally I would pick up a new one.

GT

« **Reply #4 on:** May 04, 2015, 08:20:51 PM »

Ok thank you for that would vacuum or mechanical secondary

« **Reply #5 on:** May 04, 2015, 08:30:58 PM »

Also Holley or quick fuel...

« **Reply #6 on:** May 04, 2015, 08:44:36 PM »

Tell me, what do you have for a set up? Inches? Exhaust? Type of hull etc...

GT

Sent from my SCH-I545 using SoCal Jet Boats mobile app

« **Reply #7 on:** May 04, 2015, 09:00:14 PM »

454 edelbrock performer 2.0 hardin logs 20.5 hardin hull 12jg Berkeley jet

« **Reply #8 on:** May 04, 2015, 09:34:10 PM »

Quote from: 87hardin on May 04, 2015, 09:00:14 PM

454 edelbrock performer 2.0 hardin logs 20.5 hardin hull 12jg Berkeley jet

No less than a 750 cfm.

Vacuum secondary with modified vacuum pot if you cruise it a lot.

If you are a weekend warrior and hammer down for weeks at a time, I would go 850 double pumper with a fuel pump to back it up.

GT

« **Reply #9 on:** May 04, 2015, 09:36:52 PM »

Yeah not a weekend warrior but i would like to hit it every now and then what about edelbrock carbs

« **Reply #10 on:** May 04, 2015, 09:38:37 PM »

And what about electric choke

« **Reply #11 on:** May 04, 2015, 09:40:25 PM »

What's a modified vacuum pot?

« **Reply #12 on:** May 04, 2015, 09:42:46 PM »

Mr GT i could understand if you wanted to give more information tomorrow. I know it's getting late. Thank you for helping me out , hope someday i could help out .

« **Reply #13 on:** May 04, 2015, 09:43:42 PM »

Quote from: 87hardin on May 04, 2015, 09:36:52 PM

Yeah not a weekend warrior but i would like to hit it every now and then what about edelbrock carbs

Junk (Edlebrock) for a boat

Quote from: 87hardin on May 04, 2015, 09:38:37 PM

And what about electric choke

Don't need a choke.

Quote from: 87hardin on May 04, 2015, 09:40:25 PM

What's a modified vacuum pot?

You need to order a secondary spring kit and use the lightest yellow spring.

GT

« **Reply #14 on:** May 04, 2015, 09:43:47 PM »

I have a 950 dp Holley on my 454 with a mild cam and performer as well. Best carb I have put on there hands down. I personally don't like the edelbrocks I would go holley

Sent from my iPhone using SoCal Jet Boats

« **Reply #15 on:** May 04, 2015, 09:45:35 PM »

Quote from: 87hardin on May 04, 2015, 09:42:46 PM

Mr GT i could understand if you wanted to give more information tomorrow. I know it's getting late. Thank you for helping me out , hope someday i could help out .

No problem brother. Just doing some reports and zoning while checking the boards.

GT

« **Reply #16 on:** May 04, 2015, 09:46:46 PM »

Ok looks like i will be shopping for 750 or 800 cfm I'll keep you informed.

« **Reply #17 on:** May 04, 2015, 09:49:19 PM »

Yeah i don't know what cam would be in this engine and don't want to find out anytime soon just bought the boat and would like to see it run for a few years before I go building a engine.

« **Reply #18 on:** May 05, 2015, 12:38:02 PM »

You need to order a secondary spring kit and use the lightest yellow spring.

GT
[/quote]

Can you explain this please? Thank you. I am also running a 750 vac sec and am curious about how this will improve my carb. Thank you.

« **Reply #19 on:** May 05, 2015, 05:52:39 PM »

GT if one was to purchase a new carburetor how would I know what jets to run, would it come jetted close to what i would need ?

« **Reply #20 on:** May 05, 2015, 06:30:05 PM »

Quote from: el mojado on May 05, 2015, 12:38:02 PM

You need to order a secondary spring kit and use the lightest yellow spring.

GT

Can you explain this please? Thank you. I am also running a 750 vac sec and am curious about how this will improve my carb. Thank you.

Holley offers a selection of secondary diaphragm springs to tailor when the secondaries will open. You will normally have to go to the lightest spring to get full operation of the secondaries in a jet boat application.

« **Reply #21 on:** May 05, 2015, 08:20:21 PM »

Quote from: 87hardin on May 05, 2015, 05:52:39 PM

GT if one was to purchase a new carburetor how would I know what jets to run, would it come jetted close to what i would need ?

Never.

It may be close. But just plan on tweaking it.

GT

« **Reply #22 on:** May 05, 2015, 08:21:29 PM »

Ok thats what I was thinking thanks again.

« **Reply #23 on:** May 05, 2015, 08:26:44 PM »

Quote from: el mojado on May 05, 2015, 12:38:02 PM

Can you explain this please? Thank you. I am also running a 750 vac sec and am curious about how this will improve my carb. Thank you.

Crewchief22 pretty much nailed the snot out of it.

To elaborate. A jet pump pulls the engine down so hard that the vacuum levels within the manifold are almost non existent.

This leaves the secondaries partially closed with the standard secondary spring and leaving quite a lot (imho) of performance on the table.

By using a lighter secondary spring, it allows not only the secondaries to come in earlier, but open further.

Hope this helps.

GT

« **Reply #24 on:** May 05, 2015, 08:39:41 PM »

Yes. Thank you. Gonna change the spring. What jets do you recommend?

87hardin

87hardin

crewchief22

GT Jets

87hardin

87hardin

GT Jets

87hardin

GT Jets

87hardin

87hardin

87hardin

87hardin

GT Jets

Havasukona455

GT Jets

87hardin

87hardin

el mojado

87hardin

crewchief22

GT Jets

87hardin

GT Jets

el mojado