5.7 Merc carb re-assembly.

I

idriv442

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I recently bought the boat and was told that the carb had been recently rebuilt. It is bogging down after 1/2 throttle. It ran fine the 2 or 3 previous weekends, so I have no idea. I pulled the flame arrestor off and had someone start driving it. If I held the choke (top flap of carb, think thats the choke...) closed about 1/2 to 3/4 of the way, it would hit WOT. I am not great with carbs but it seems the throttle should interact with the choke. I have pictures of the carb as it sits now. Is the carb set up correctly or is there something missing. I have searched for days trying to find a picture of this side of the carb with no luck.
2012-07-12 18.00.16.jpg
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Don S

Don S

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Re: 5.7 Merc carb re-assembly.

What year engine we working on here.
1. It's not a Mercarb, it is a Rochester.
2. What's with all the red sillycone around the carb base? That alone could be half your problem.
 
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Failproof

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Re: 5.7 Merc carb re-assembly.

That carb looks cobbed together from somebodys carb pile. Probability of mixed parts is 100 percent, not an issue if everything was done correctly. If you had to hold the choke closed to get wot, probably have a plug jet or bleed. Start with a good cleaning and inspection.
 
I

idriv442

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Re: 5.7 Merc carb re-assembly.

Sorry, Forgot the year. I believe it is the original motor that came with the boat, which is a 1976. It still says 233h.p. on the valve covers along with mercruiser marine on the opposite side. The stamp on the intake is D5JE-9425-EA (may be an FA). As for the silicone, I guess he didn't want it to leak. Thanks for the quick response.
 

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Don S

Don S

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Re: 5.7 Merc carb re-assembly.

It's a Ford 351 engine. I would guess the sillycone is because the PO was too cheap to put a new gasket on.
Put a new gasket on it, and clean that red stuff out of everything and see how it runs then.
 
I

idriv442

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Re: 5.7 Merc carb re-assembly.

Will do. Hope to get it done tomorrow. Thanks for your help. And there is a gasket there as well. It is sandwiched between the red stuff. Hope to take her out soon and see if I can do more than the 40mph I got last time.
 
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