Edelbrock 1403 runs rich after cleaning

[5Tractorguy]

Just cleaned the carburetor on my '77 GMC with RV cam 350. Was running a bit choppy before hand but had good economy (12.5 mpg). Now after cleaning it runs smooth as it should, but is running rich. Not enough to see out the tail pipe, but enough to watch the gauge needle move on a 10mil round trip.

Anyone have experience with these carburetors? This one is new to me...

I also have a lot more vacuum than before when slowing down (25) vs (20+/-) and when I'm accelerating normally it's much less, around 8 or so. Cruising 15+/-. Maybe the change in vacuum is pulling my metering rods up resulting in more fuel?

Everything was washed out with brake cleaner, blown out with air, floats adjusted to book, all vacuum and external lines running to carb reassembled in the correct location. Choke is not sticking.

Any thoughts are appreciated!

[Dead Parrot]

According to the Edelbrock website, the 1403 is tuned for performance. Which usually means rich. Sounds like your dirty carb had found a sweet spot for economy and now that you have cleaned it, it can act properly.

Here is a like to a forum posting with LOTS of good info:http://67-72chevytrucks.com/vboard/s...d.php?t=736001

The third link in the posting has some tuning info on Eddy carbs.

Hopefully you noted which rods and jets you had while it was open. Your fix might be as simple as ordering some new leaner rods and springs.

[akart]

There is a kit (EDL-1486) which has quite a selection of rods, jets and springs,about 60 bucks. I bought one w/my new carb and got to where I wanted. Try a few changes. Lean it out till too lean then back up one.

[5Tractorguy]

Thanks guys.

I do have that 1486 kit akart, came with the truck when I bought it. It has a number of rods and springs so I just have to figure out the color code of the springs and I can try swapping in a lighter one.

Driving around today it looks like 35-50/- is the lean spot. Previous owner installed an LED meter on the dash that shows how rich it's running. Once I get below 18 vacuum, the meter starts to go up, so that tells me that the rods start to pull up then.

Also have to check the idle screws again, sounds a bit rich, but it could be the cam too.

On the upside though, its got some juice now! Which isn't bad since I move a lot of equipment and tractors.

[akart]

Originally Posted by 5Tractorguy

Thanks guys.

I do have that 1486 kit akart, came with the truck when I bought it. It has a number of rods and springs so I just have to figure out the color code of the springs and I can try swapping in a lighter one.

Driving around today it looks like 35-50/- is the lean spot. Previous owner installed an LED meter on the dash that shows how rich it's running. Once I get below 18 vacuum, the meter starts to go up, so that tells me that the rods start to pull up then.

Also have to check the idle screws again, sounds a bit rich, but it could be the cam too.

On the upside though, its got some juice now! Which isn't bad since I move a lot of equipment and tractors.

akart again, The spring doesn't adjust the mixture,just when/how fast things happen. You are going to want to change the rods to adjust the mid range area which you have determined as being too lean. The jets will determine the fuel flow @WOT. I like the Eldelbrocks as I/you can tune it. Tuning info should come w/the kit or was it the carb, but if you have questions check the Eldelbrock site for the manual. Idle screw only adjusts the mix at idle.