Not sure where to put this......

[Skee]

Not sure where to put this thread so,sorry Mr. Administrator if it's in the wrong place anyway..I just bought a Spectra from here with a 460 Ford motor,it has a 600 cfm Holley Carb...I was going to rebuild/re-use it on this boat,but I have a 780 Vacuum secondary that has already been rebuilt that I can put on it....any input on advantage/dis-advantage on using the 780 instead of the stocker 600?? Any help would be great guy's! :beer Thanx...Tracy aka "Skee"

 

[DirtyWhiteBoy]

might as well PM Sleeper CP


Only a few F F FF (I can't say the F-word) BBF's still in captivity




Congrats!:beer

 

[Outnumbered]

I ran a 800 CFM Barry Grant mechanical secondary carb on my 350HP 460 motor in my 21 Lavey with no issues. It was an OMC marine motor that came with a 600 from the factory. It took some tuning on the secondaries to work out the bog but after that the motor ran perfect. Mine was an I/O. If you have a jet you will really like the bigger carb, assuming that 460 is not a truck motor.

Also, make sure your carb is a marine carb with "J" vents.

 

[Skee]

might as well PM Sleeper CP


Only a few F F FF (I can't say the F-word) BBF's still in captivity




Congrats!:beer

Well....I have 2 boat's 77 18 1/2 Challenger (Hot Rod) with a 454 Bow Tie with a Jacuzzi WJ and now ,new to the brood,a family toy, 78 Spectra, 460 Blue Oval with a Berkeley "E" pump... :beer

 

[Skee]

I ran a 800 CFM Barry Grant mechanical secondary carb on my 350HP 460 motor in my 21 Lavey with no issues. It was an OMC marine motor that came with a 600 from the factory. It took some tuning on the secondaries to work out the bog but after that the motor ran perfect. Mine was an I/O. If you have a jet you will really like the bigger carb, assuming that 460 is not a truck motor.

Also, make sure your carb is a marine carb with "J" vents.

Neither one of them have them.....

 

[Outnumbered]

No J vents under a hatch or open? Technically bad either way but very bad under a hatch.

 

[Skee]

No J vents under a hatch or open? Technically bad either way but very bad under a hatch.

It's under a hatch,but blower work's very well and also running the USCG spark arrestor/air filter also. Could I add the J vent's to it? and if so where would I purchase them? Thanx:beer

 

[Outnumbered]

It's under a hatch,but blower work's very well and also running the USCG spark arrestor/air filter also. Could I add the J vent's to it? and if so where would I purchase them? Thanx:beer

You can but there are other marine carb differences. Best to just use a marine carb.

I googled and found these threads on another forum.

http://www.speedwake.com/upload/showthread.php?threadid=49336

http://www.offshoreonly.com/forums/general-q/48867-auto-marine-carb.html

 

[DirtyWhiteBoy]

Neither one of them have them.....

that is not a good thing, by the time you notice the float is stuck........BNAG! tooo late:hotdevil

 

[TAF]

I just sold my '77 Spectra to Ratty59 w/ a Ford460 w/ 780 Holley and it worked just fine:thumbsup

 

[RitcheyRch]

Congrats on the new boat.

 

[69 1/2]

Has to be a marine carb with the J tubes. Around here they watch that pretty close as one went "BNAG" not long ago with terrible results.

Isn't the 780 a spread-bore carb anyway? Suppose one could work with an adapter plate or intake manifold change.

 

[wUTwZAT]

I am no expert on this but I believe a vacuum secondary carb on a boat is usually no good, I have always been told to use a mechanical secondary carb. Just what I have been told bt people I trust.

 

[RadMan]

You can buy the j-tubes from Jegs, just a couple bucks. Not in the catalog, but might be online. I just called when I ordered mine asking for those j-tube thingies or something like that. You can simply pull the old ones out with pliers, getting the new ones in is a tight fit, I froze mine and it helped a little.

Another difference I think for marine carbs has to do with the throttle shaft design, marine ones are modified I believe to prevent fuel from flowing out the shaft if fuel were somehow dumped on closed butterflies. I think there is an additional third difference as well, but not sure what it is.

I think your 780 would be a good improvement over the 600 once jetted and tuned properly.:thumbsup

Edit: As mentioned, the vacuum secondary might be an issue on the boat. Missed that originally.