4 bbl carb jetting

[party barge]

I bought a new Edelbrock Marine 600 that was an exact replacement on my 95 260 mercruiser that was equipped with a factory Carter/Weber. I toosed it out and then used the new one. It seemed to be flat on top and was missing 400 RPM from the previous carb.

Does anyone know where I could find what jets and metering rods was in the Mercruiser carb so I can clone the new one?

 

[Don S]

Re: 4 bbl carb jetting

Might want to read your "Tube flappers" thread. You may just have other problems with your engine that jets and carbs won't fix.

 

[John_S]

Re: 4 bbl carb jetting

If you do try to compare to Merc webers, make sure you are looking at early 90's 600cfm specs. Merc used both 600 and 750 webers on the SBs. The 600 was used more on 5.0LX and 5.7Ls. The 750 was generally used on 5.7LX and 350Mag. Then in the mid 90's went to a two step rod, which is not compatable with your Edelbrock.

The Edelbrock 1409 is set-up is slightly different than Mercs, but so many people have used it out of the box with no issues on SBCs, I'd say you have something else going on. Even if it was the carb, just tune the one you have. They have a good tuning guide.

PS: Also, to compare, you need to look to calculate the area, not just use the diameter. Here is what I have in specs:

Model - Primary Jet - Secondary Jet - Metering rod - Metering Rod Spring

9661 - .104 - .101 - 7147 - natural
9665 - .101 - .095 - 7052 - pink
1409 - .098 - .101 - 6847 - orange

 

[party barge]

Re: 4 bbl carb jetting

When I first got the boat and up until I got a salt water intrusion it would allways turn 4400. This was with the unmolested motor now with the weber carb. With the rebuild motor it only turned 4000 and seemed flat on the secondarys and this was with the edelbrock. I allways run around the Gulf at 3000 anyways but when I redo this mess I got I wanna be ahead of the game on the carb thing is all. thanks

It was a 9665