Carburetor or throttle body

JW76

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Jul 5, 2017
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So my 96 4.3l LHX has been having some issues with filling the carb up with fuel when I decelerate to idle or leave the key on. I decided to put a kit in it but when I priced one for the carter 4 barrel that I have it was around $170. My question is at that price would I be better off buying a throttle body? Thanks in advance for any opinions and info.
 

Bt Doctur

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Aug 29, 2004
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So my 96 4.3l LHX has been having some issues with filling the carb up with fuel when I decelerate to idle or leave the key on

So fix whats wrong. How does a carb fill up in decel when your cutting the fuel off and you need a pressure switch inline with the electric pump to prevent the pump from running with the key on and motor off
 

JW76

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Well it seems like it floods out and dies then it’s difficult to get started again. But when I turn the key off as I’ll slowing down it fires right back up. I’m no mechanic so that was my reasoning. Thanks for the answer I’ll check into the pressure switch.
 

achris

More fish than mountain goat
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May 19, 2004
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So my 96 4.3l LHX has been having some issues with filling the carb up with fuel when I decelerate to idle or leave the key on. I decided to put a kit in it but when I priced one for the carter 4 barrel that I have it was around $170. My question is at that price would I be better off buying a throttle body? Thanks in advance for any opinions and info.

Edelbrock 1409 overhaul kit, which includes a couple of new floats, is $43. https://www.summitracing.com/int/parts/edl-1477/overview/ Which is exactly the same as the Weber 9600 you have on the engine currently.

Throttle bodies are for fuel injection, not carbs. You can't buy a 'throttle body' to replace a carb, not without a handful of injectors, a high pressure fuel pump, an injector fuel rail and a whole new wiring loom.

Well it seems like it floods out and dies then it’s difficult to get started again. But when I turn the key off as I’ll slowing down it fires right back up. I’m no mechanic so that was my reasoning. Thanks for the answer I’ll check into the pressure switch.

2 things from this. Firstly, shutting off the engine as you slow down invites a cylinder full of seawater. Really bad practice. Second, your test and conclusions don't make sense.

If the carb IS flooding, then it's because the needles are damaged. Just putting a new pressure switch in will not solve that. Even if the pressure switch had failed 'closed', the needles should shut the fuel off when the carb fuel bowls are full.

The problem lies in the carb. Pull it off and fix it.

Chris..........
 

Scott Danforth

Grumpy Vintage Moderator still playing with boats
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Jul 23, 2011
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So my 96 4.3l LHX has been having some issues with filling the carb up with fuel when I decelerate to idle or leave the key on. I decided to put a kit in it but when I priced one for the carter 4 barrel that I have it was around $170. My question is at that price would I be better off buying a throttle body? Thanks in advance for any opinions and info.

I will sell you carb kits at half that price all day long..... as Chris mentioned, they are between $30 and $45 (under 50 with a can of carb cleaner)

Chris already answered the throttle body comment.
 

JW76

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Jul 5, 2017
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Thanks again guys that looks like the perfect kit for a first timer like me?
 

JW76

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Jul 5, 2017
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Just to double check will the 1477 kit in the link work for the 1409 or the 9600s?
 

JW76

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Jul 5, 2017
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Well the kit is in and all went well. The needles didn’t look bad but the floats weren’t even close to adjusted properly. It’s possible that the P/O had put a kit in it since I’d had the problem to some extent since I’d bought it. Now just need to reinstall and tune thanks again for all the help.
 

JW76

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Jul 5, 2017
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Good news is that the carburetor is back on the boat and functions. The bad news is that the fuel pump still doesn’t shut off when the key is on. There is no fuel escaping thr needle valves but it still runs. No sign of an in-line pressure switch. My engine is a 96 vortec, so would it have a pressure relay and if so where would I find it?
 

achris

More fish than mountain goat
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May 19, 2004
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27,468
No relay from factory, only the pressure switch, which carries all the current. Switch should be tee-d with the oil pressure gauge sender, right above the oil filter boss on the port side of the engine, under the exhaust manifold. Chris.......
 

JW76

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Jul 5, 2017
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Installed a shut off switch and tuned the Carburetor this weekend and ran the boat for about 6 hour. It ran much better for most of the day but toward the end of the day began to die at idle again and took a quite bit to start again. It started much easier when I’d move the throttle control forward a bit. I noted some slop in the throttle cable while tuning. Could this be the problem or does anyone have any other ideas?
 
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