By list number that is a 850 cfm and jets are 88/96.
I think carb bigger than needed but think there is another problem also.

Is this a 330hp454 or 365hp 454 ?

What part # Eddy intake ? Got a pic of it on the boat ? What I’m getting to on intake questions, if a spread bore intake, it needs a thin adapter/sealing plate between squarebore carb and spreadbore intake for carb baseplate gasket to seal.

Edelbrock 2732


https://cimg1.ibsrv.net/gimg/www.off...30e8e67a6.jpeg

Post #47, with the pic of your spark plug, has me wondering if that is fuel or oil fouled. Oil fouled will be shiny. Fuel fouled will be shiny too until the fuel evaporates, then it turns to a dull black. Curious if the old plugs still look shiny or not.

Also, what does the exhaust look like? If you running rich enough to foul the plugs, the exhaust should be a black color. If oil is burning, it will be a blueish color..

I'm not sure which 454 it is. It's a 1993 with a bravo 1.
https://cimg9.ibsrv.net/gimg/www.off...0fdde521e7.jpg
https://cimg8.ibsrv.net/gimg/www.off...5e8e9c2296.jpg

I was able to regulate fuel pressure down to 5-6psi and there was no change. Still no idle. I'll also add that I can get a pretty consistent backfire through the carb on a restart with to much throttle, and if I try to save it after it wants to stall. It let's out a backfire through the carb, and then will pick itself back up and run

Have more questions before statement :) . This is your pic from post #14. Where does that black vacuum line from carb go to ?


https://cimg8.ibsrv.net/gimg/www.off...49ed86c79.jpeg

It is capped off

Transom is getting black from the exhaust, Ill get a picture of the old plugs tonight but they are definitely a dull black now.

Black soot is rich. As Smitty said, all things being good, likely a power valve. They do not like backfiring-- at all. You might squeeze 1 or 2 by it, but it sounds like it's been pounded. PV is ported to the manifold and takes a direct hit. It's in the metering block, unscrews, has a number stamped on the face representing vacuum to open. It's kind of odd. Idle vacuum divided by 2 gives the number of PV you need. If you don't know the idle vacuum, a 6.5 is a safe bet. Try it, might be the fix. It ​​​​​​​

I have already replaced the power valve with no change. I was able to briefly measure vacuum a while back at 1000 rpms and it was sitting right at about 12. The power valve that was in it before was a 6.5 and I replaced it with a new 6.5