Replacement marine carb

[Donzi_Dude]

My bone stock 502 with the 750 Edlebrock will turn 5000rpm pushing my 22C to 73mph GPS... Then, throttle back and she idles at 600rpm... No issue! knock on wood

i thought bone stock 502 run 76-78 in those boats...

[duckhunter]

Another vote for the Edelbrock 1409 600cfm carb for a small block!

It's as close to plug-and-play as you can get. I have a huge box of Holley parts and have used & tuned them extensively, but went with an Edelbrock and couldn't be happier.

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[Pat McPherson]

i thought bone stock 502 run 76-78 in those boats...

Maybe, but I've not ever heard that. I've seen guys say 74-75 on GPS running a 3blade.
I run a 4 blade and it probably cost 1mph. Every boat is different.

Again, Matt was asking for opionions for a replacement carb that was plug and play, not one that would eak out every last HP from his engine.

[Pat McPherson]

Another vote for the Edelbrock 1409 600cfm carb for a small block!

It's as close to plug-and-play as you can get. I have a huge box of Holley parts and have used & tuned them extensively, but went with an Edelbrock and couldn't be happier.

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Vary well done!
Here's mine; it's got a turd for a carb and the boat only tops out at 73, but...

[Sidney073]

The Edelbrock is a great carb, the only thing in my opinion that is unique about it is that it uses metering rods, and jets for tuning. It has a Power Valve which is a piston type like GM factory carbs. They usually are plug & play on stock or near stock engines. The thing with Holley's is that you can find tuning parts everywhere. Jets, Power Valves, etc are plentiful. The Power Valve is very important to idle quality, and on performance engines it must be tuned to the Idle Vacuum of the engine, they are available from the stock 6.5" vacuum stock down to at least 2.5" vacuum for high performance cam profiles. There is also a plug to disable it entirely, which requires richer jetting to compensate for its removal.
Also another thing with Holley Marine carbs is they have spring loaded needle & seats to prevent flooding from the rough ride on the water, if a standard needle & seat is used intead this could lead to flodding from the fuel level rising.
I am currently tunning a Predator VV Carb on my 383 in my 76 Classic 18, and I love it, runs like it has EFI.

[duckhunter]

Vary well done!
Here's mine; it's got a turd for a carb and the boat only tops out at 73, but...

Looks great!!

The Edelbrock is a great carb, the only thing in my opinion that is unique about it is that it uses metering rods, and jets for tuning. It has a Power Valve which is a piston type like GM factory carbs. They usually are plug & play on stock or near stock engines. The thing with Holley's is that you can find tuning parts everywhere. Jets, Power Valves, etc are plentiful. The Power Valve is very important to idle quality, and on performance engines it must be tuned to the Idle Vacuum of the engine, they are available from the stock 6.5" vacuum stock down to at least 2.5" vacuum for high performance cam profiles. There is also a plug to disable it entirely, which requires richer jetting to compensate for its removal.
Also another thing with Holley Marine carbs is they have spring loaded needle & seats to prevent flooding from the rough ride on the water, if a standard needle & seat is used intead this could lead to flodding from the fuel level rising.
I am currently tunning a Predator VV Carb on my 383 in my 76 Classic 18, and I love it, runs like it has EFI.

There are tuning kits for Edelbrock available for short $$, along with very straightforward tuning and troubleshooting instructions. Good point on vacuum - a vacuum gauge is a must-have tuning tool for carb motors IMO, and pretty darn available & easy to use.

There are more parts and configurations available for the Holley, which is a blessing and a curse for many folks. You can really chase your tail trying different jet/power valve/air bleed/accelerator pump cams/pump nozzles/etc combinations. Pros can get the most out of them due to their extreme modularity/tunability. For most of us normal Earth folks the Edelbrock is just a lot easier to go bolt on and go boating.

The Predator carbs are awesome; I'd love to try one on a boat.

[Pat McPherson]

Hey Matt,
I have a 4 hole adapter off a 454mag if you need it. My 502 needed the open adapter.
Patrick

[mattyboy]

Pat

thanks! really appreciate the offer but i was wrong it is a square bore weiand spent some time and re tuned the holley will check this weekend hopefully get the last month and a half of the season out of it

[Lil Grizz]

I just spent the last 2 months re-overhauling Dads Corsican with a 351c. It had a Holley 650 on it (and another 3 on a shelf) which I replaced after fighting to dial it in right. Same with the spares which I'll be unloading shortly if anyone here is interested.

Not a big fan of the Edelbrock which I also have a few of so I replaced the 650 with a Holley 750 HM-BK Marine from AED. 74 primary and 82 secondary jets. Worked like a charm and was easily dialed in. I'd be happy to share the additional tuning specs to get you in the ballpark if you go this route.

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[BUIZILLA]

the 650 you took off was a 4010 series, the WORST carb Holley ever built, EVER, and wayyy too small for that engine in the first place

what you put on is what should have been there all along

[Lil Grizz]

the 650 you took off was a 4010 series, the WORST carb Holley ever built, EVER, and wayyy too small for that engine in the first place

what you put on is what should have been there all along

Thanks! I did a lot of homework before deciding on that 750.

I wouldn't call the 4010 the worst ever but you're right in that respect that they have a really problematic design for consistency. Very sensitive to any trash that gets in there. Honestly the carb was the least of the problems I've had to sort out so far but the last thing I wanted was a PITA which that 650 certainly is.