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Has anyone rebuilt Webber DCOE 40's before?


Guest oldZguy

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Guest oldZguy

Looks like I'm going to have to get into mine and was looking for any hints or tips from someone that has been there before. I'm sure I'll be an expert by time I'm done with the third one but the first one will be the learning experiance :) Nothing worse than tearing into something for the first time that you can hold in your hand and has over 80 small parts!

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oldZguy,

 

There not that bad.

Just take your time, make notes/diagrams as to where something goes, size or # on each jet etc.

Most important - Make sure ALL carbs are set / ajusted the same, ALL with the same jetting.

You will need a tool to synchronize the carbs after you go thru them.

http://piercemanifolds.com sells a really good book !

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Guest oldZguy

I've been running these webbers for a long time so the adjustments are no big deal. I guess I was looking for the "watch out for this flying spring or get this check ball in the right place" kind of stuff. Figure it can't be any worse than rebuilding an old Quadrajet :) Glad I don't have any of them around anymore :D

 

The carbs are probably 20 years old and the car hasn't run in the last 15, got it started up last month and I'm bringing her back to life. The carbs were pretty gunked up and don't transision well so I figure I might as well bring them up to snuff with the rest of the car.

 

Thanks,

Lance

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I guess I was looking for the "watch out for this flying spring or get this check ball in the right place" kind of stuff.

 

Yes !

 

The carbs are probably 20 years old and the car hasn't run in the last 15' date=' got it started up last month and I'm bringing her back to life. The carbs were pretty gunked up and don't transision well so I figure I might as well bring them up to snuff with the rest of the car.[/quote']

 

You might want to have the tank cleaned, or at least drain old fuel.

Change the fuel filter often for a bit after you get it going

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I have re-build several sets of Weber DCOE 40's.

 

Some tips (that I can remember):

 

1. Check for corrosion where the throttle blades meet the throat of the carbs. Close the idle stop screws completley and shine a flashlight down the throat looking for leakage around the blades. Minor pitting can be repaired with JB Weld.

 

2. There is no need to remove the throttle shafts unless you have to repair/replace a bent shaft or replace the ball bearings. They are a pain to remove without damage and the throttle blade screws are swegged (spelling?).

 

3. Corrosion in the float bowl can be removed by blasting with walnut shells or plastic media.

 

4. There is a BB sized ball used in the check valve of the accelerator pump (two per carb). Watch for them. Easy to loose.

 

5. Use a quality rebuild kit and follow the exact instructions about setting the float height.

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  • 3 weeks later...

Definately leave the throttle shafts alone.

 

If they have been sitting that long, it is a good idea to strip them down... more importantly strip out all of the gaskets.. (just don't touch the gaskets for the throttle shafts)

 

Soak the whole thing in carb cleaners. I used the WD40 with the red nozzle hose.. it fits into many of the passeges.. and when spraying it can help you figure if any are plugged.

 

I also used lots of water in both directions through every single passages I could get at.

 

After using water, let dry, and spray all the passages, insides with some penatrating oil (so nothing seizes up going back in)

 

The floats are extremely critical.. far more than most know.. you need them to operate (distance to closed position and distance to fully open ) exactly what the manual says. dcoe 40 18's 7mm closed 15 open. measured including the gasket. it doesn't measure to fully closed either... it measures the point in which the float arm lightly touches the needle valve. 1mm difference is a big difference.

 

Float heights are critical in setting rich/lean conditions.. a 140 main jet with a high float can flow more fuel than a 140 main jet with a low float level. it can make tuning a nightmare.

 

make sure the carbs are mechanically balanced. again accuracy counts. spend the time there with the carbs off the car. it will make the initial tuning much easier. again. 1mm difference between throttle linkage lengths is too much... it makes low end driveability suffer.

 

Thats all I got off the top of my head.

 

Good luck

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