Weber Carb Cleaning Restore

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pecx
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Weber Carb Cleaning Restore

Post by pecx »

I was searching for how to clean/restore the carbs. I just share what I found. :action14:

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Weber Cleaning
http://www.alfabb.com/bb/forums/carbure ... rbies.html" onclick="window.open(this.href);return false;
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By Gordon Raymond at http://www.alfabb.com" onclick="window.open(this.href);return false;
It's done by a complete disassembly followed by media blasting the castings after they have soaked at least 24 hours in a nasty solvent bath, the main ingredients being lacquer thinner and toluene. The best media is glass bead dust, collected from the vacuum dust catcher in a media cabinet. This dust at 60-70 psi does not imbed, and can be washed off with water. The passages are blasted with 175 - 200 psi air to clear them. If this does not work, the lead seals must be removed for manual rodding-out. Brass components are wire brush cleaned with the finest brush available followed by checking each jet with Weber jet plug gauges. It is all hand work.
The resulting finish is exactly as Weber finished the castings. On older versions, the magnesium in the alloy will quickly develop a darker color in small spots and blotches, just as they did when new. No acid or base cleaner can replicate the original factory finish. It's taken me about 40 years to perfect this restoration technique, done carefully, most, (not all) aged or abused DCOE series Webers can be restored to original factory appearance and function.
The solvents are nasty, and the media work takes practice. My Alfa business is purpose built street and racing oil pumps, but I also do Weber restoration when I have time.
Here is a before and after of very early 40DCOE2 large top Weber restoration. These are both numbered in the low 500's.
This work is not inexpensive as it is time consuming, but still generally cheaper than new Italian replacements.
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As usual there are some weber tricks involved. The brass shafts can be replaced if twisted, but the more common need for replacement is wear in the center bushings from the spring pressure. Sometimes a slight twist can be corrected, but with wear and a bow in the center you get uneven idle no matter what you do.

The butterfly screws are interesting. The early brass ones can be "unstaked", removed and re-used, (sometimes). The new steel ones I grind off the staked area and use new ones. The new ones are glued in with either Loctite Red, or number 290 Green, depending on the situation. I do not stake these, as they never come out. BTW should a brass one get into an engine, it does MUCH less damage than the steel ones!()

I have a set of Weber jet drills (vey tiny and very fragile!) and a set of plug gauges. These are not used as you would suspect. I recently had a #65 starter jet plugged hopelessly. A # 60 Weber drill was used in my fingers to get a hole through the plug. Then a #60, #62 and #64 plug gauge was used to clear the remainder of the plug using lacquer thinner as a lubricant and cleaner. Finally it was blown out with Brakeclean and air and checked with the #64 gauge that should pass freely. The #65 would be used to check for any OVERSIZE jets. The correct # gauge is a TIGHT fit in the jet. NO wire or drills in the jet orifice unless undersize.

Body passages that are hopelessly plugged must be cleaned the "hard-way". I remove the lead plug and manually clean them out with regular twist drills, either hand held, or using a pin vice. Once cleaned, I can either re-plug with lead, or I prefer to tap the end of the gallery and plug it with stainless steel (hard) little metric allen screws held in with Loctite Blue. This allows for future removal and clean out with less hassle.

I have no secrets, as I've learned this over MANY years. If I share my experiences, others will benefit.

I hope this helps!
Some other examples, both from Keith Goring. The first three pictures are a set he sent me as the dirtiest Webers he had seen. Not a cheap job, but they came out new. The fourth picture is an "after" picture of a early pair of 40DCOE2 race Webers. They had been externally polished shiny, like chrome!!! Now they look the way they should. This took three different grades of media.

I believe I may have dissolved myself. The solvent thing is something best done right before shop evacuation, or outside. ALWAYS far from open flame or any source of ignition. That is, without a doubt, the worst part of Weber restoration.


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The most common area's of glop (Not varnish. Varnish is used in painting, glop is accumulated hardened crud of all sorts.) is in the pump pistons. They will stick, and you get no squirt of gas with throttle opening. By the time this happens, usually the "catacombs", the drilled and plugged passages in the bottom of the body casting, are also full of glop. Webers in this condition will never operate properly.
The best solution, is removal and a rebuild by someone knowledgeable. Short of that, first try Gary's trick, then remove the tops of both Webers, and the garbage can lids, aka "jet covers", 5 screws each. Carefully lift off each top and set it somewhere where it won't fall or get confused with it's mate. Remove all the fuel in the float bowl on each. Refill each with GUMOUT SPRAY Carb. Cleaner, to a level higher than the fuel was in the bowls.(YOU MUST BE CAREFUL WITH THIS STUFF> IT REMOVES PAINT!) Get in the car and pump the gas pedal three times. (Thats enough!) Just set the Weber tops back in place with floats and all. Do not screw together,use the garbage can lids (Jet cover) to hold it together. Let it all sit overnight. Remove the Weber tops again, refill with GUMOUT if necessary, and pump the gas pedal three more times. Remove as much of the GUMOUT as possible. The engine will not run well on this stuff. Remember, be very careful with it as it will remove paint! Reassemble the Webers, being sure to tighten the 5 top screws evenly. Replace jet covers. Crank the car until it starts. Better? If not, it's time for a rebuild.
Gumout spray carburetor works pretty good for most DIY jobs. I use more aggressive means on those my customers send me for work.
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For restorations, I have two different cleaning methods that are not available or practical for the DIY job.
For the individual, a long soak in a 50/50 mixture of kerosene and lacquer thinner (2 or 3 days or more) softens thing up pretty good. Then a external spray of "Aircraft paint remover" available at some large hardware, automotive or paint stores, followed by a thorough rinse in GumOut spray carburetor cleaner, and then another soak in the Kero/Lacquer mix ( to get rid of the paint remover) is about as good as the DIY owner can do. Do NOT use plastic toothbrushes or the like with any of this stuff. They just melt. Do NOT use any ammonia based paint remover as it will turn the aluminum black. A STIFF, throw away, natural bristle brush in wood is OK. Weber bodies, and particularly the four screw bottoms were made of many different aluminum alloys over the years. Some contained enough magnesium to easily stain and / or turn black or blotchy. Any acid or base type cleaner ( Like Easy Off Oven Cleaner) Will make a real mess. Stick with SOLVENTS. Please, protect your skin, lungs and eyes when using these cleaners. 200 PSI air pressure blows out a lot of crud. Again, protect your body.
If you want them "like new" send them to me and I can do any degree of restoration you wish. Send me a PM for more information if you are interested. This pair of 40DCOE139's spent some time under water and suffered some serious corrosion, but were returned to the owner yesterday looking like this.

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After reassembly, back out the idle adj screw on rear carb with the throttle linkage (from gas pedal) disconnected. The plan here is to COMPLETELY close all four butterflies. Lift up on the little ball of the linkage, and turn idle adj screw in & out to be sure butterflies of #2 (rear carb) are closed. Holding the little ball up, now act on the hex screw that links the two carbs together. You want the slack in the spring removed (spring toward manifold) and the hex adj screw out j u s t far enough to insure that the butterflies of #1 carb are also closed. You can push the "u" shaped link toward the manifold, (with your third hand) to insure #1 is also closed. WHEW! (have a beer{see "what beer do you drink" thread in this BB for advice}) Now, turn in the idle adj screw on carb #2 until the butterflies begin to open. (linkage will begin to move).
From this point, turn in an additional one revolution. this will give you a very fast idle.
Next, air correction screws (4). Turn in all 4 until they g e n t l y seat. Force here can push them through and inlarge the correction hole (BAD). Once seated, back off each 3/4 turn.
Re attach disconnected gas pedal linkage. Now you can try to start the car. Once running, back off or turn in idle adj screw until idle is 800-1000 rpm. Engine may not be running very well.
starting at the front, act on each air correction screw in what ever direction it takes to increase idle speed. This should not be more than 1/2 turn in either direction. If idle gets above 1000 rpm while doing this, back off idle adj screw to get it back to 800-1000. After all 4 are adjusted, do it again, starting from the front. Once you are satisfied that you have this about right, ONLY THEN try a slight adjustment of the hex screw on the connecting linkage. You are now balancing the butterflies by "ear and feel".
Turn this screw in and out about 1/2 to 1 turn listening and feeling for the engine to run smoothly, noticed by lessening vibration. Check idle, still should be 800-1000. Adj as req. Engine should be HOT by now. Lower idle to about 800 and again try adj. all 4 air correction screws for max engine speed. Again, a slight check of balance adj screw for s m o o t h n e s s.
Finally, set idle where you like it 800-1000 or a little higher if you prefer.
Do NOT mess with balance hex screw again unless engine is not smooth. (You replaced the plugs and checked the ignition, didn't you?) Ignition timing and ignition condition are the # 1 reason for hard starting, bad running Alfas. (remember rule 1: "don't mess with the Webers")
Now, shut it off and have another beer. Best, Gordon Raymond

dr.occa
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Re: Weber Carb Cleaning Restore

Post by dr.occa »

:tu: Soda blasting is sweet. Cheap method as long as you've got an air compressor. Vacuum physics err-buddy. I always forget to do this.

It's called the Bernoulli effect. I'd do it in maybe like a container to recapture some of the baking soda.

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pecx
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Re: Weber Carb Cleaning Restore

Post by pecx »

Jonas do you know any zinc plating service in town? ) That accept small volume of stuff

joel26
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Re: Weber Carb Cleaning Restore

Post by joel26 »

Nice find..
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dr.occa
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Re: Weber Carb Cleaning Restore

Post by dr.occa »

pecx wrote:Jonas do you know any zinc plating service in town? ) That accept small volume of stuff
Yeah, tried Allied Powder Coatings off of Augustine (6011 St. Augustine) between 288 and 45. They should be really close to where Griggs intersects Old Spanish Trail.

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