Prior to jumping into the carb rebuild, I did some research on the internet about Weber Carbs, rebuilding, etc. There really is not a lot of how-to information on carb rebuilds.  Thus I'm making more of an effort to document my experiences.  A lot of the information here would be applicable to most carb rebuilds, so extrapolate as you wish.



The CX 2200 has a Weber 34 DMTR, which is part of the Weber two-barrel, progressive family.  "Two barrels" because there are two barrels, and "progressive",  because the throttle plates open progressively, not in unison.  It is not until the accelerator is at least 2/3 down that the throttle plate in the second barrel opens.  I am very impressed with the design of the Weber carb.  It's a nice and elegantly simple unit.  Given the complexity of the task, it has remarkably few moving parts.  Most of the fuel metering is done with relative air pressure, not valves or needles with oil dampers.

Click here to see an very good introduction to Weber Carburetors.



Here are some recommendations on rebuilding your carburetor. 


You really need to understand the theory of the Weber carbs before you jump into a rebuild.  There are so many variations within the Weber families that you are unlikely to find a manual that addresses exactly your carb.  However, this is not  a problem if you have an understanding of how the circuits, etc. work..  I found that the DMTR was very similar, but not exactly identical to the carbs demonstrated in Haynes.  All the principles of Weber carbs were there on the DMTR, but just in different locations. All of the components of the Weber carb were present on mine, just arranged differently from the carb rebuilt in the book. If you understand how carbs work in general , you'll be better able to understand your carb, even if it does not match what you are looking at in the book.   If you understand the .principles, you can say "ok, here's the second circuit emulsion tube, even though the carb in the book has it in a different place."   You're going to have to be able to recognize the idle/low speed, primary and secondary circuits, and accelerator pump on your carb, just by looking at where the fuel & air is ducted.  you cannot depend on a book to show you exactly where it is.

That being said, where to get information?


Several Sources:

The Haynes Techbook.  Haynes  publishes an excellent book on Weber carbs, with thorough explanation on the theory and practice of their operation.  Buy it and read it several times,  even before you think about getting started.  There is another book on Amazon that presents Weber carbs, but I did not think it was as helpful as the Haynes.   The Haynes book does not address the DMTR specifically.  However, you will find that the DMTR is part of a family of carbs, a member of which is rebuilt in the book.  You will also need the Haynes shop manual specific to your car, as it will have some information on the specific carb fit to your engine.  There will be diagrams showing the jets and emulsion tubes for your carb, and their locations.

Pierce Manifolds I purchased my rebuild kit from Pierce, and I highly recommend them.   Their website has exploded diagrams of all the carbs they support, and you will find  these diagrams are infinitely valuable when you rebuild.  They also gave me technical advice over the phone on several occasions.  Even if you do not use it, it is nice to know that there is a resource there - if you come across something you do not understand, they can talk you through it.  Excellent before & after sale service. 

Here is a .pdf of the DMTR exploded diagram


Shane, in Australia, did an excellent documentation of the rebuild of his DMTR carb.  The information here is meant to be a adjunct to what he has already accomplished so well.



2} A WEBER Rebuild is not really a "rebuild".

It's really a thorough cleaning.  The elegant part of the Weber carbs is that they have very few moving parts. Fuel metering is determined by the internal passages and the holes on the emulsion tubes, not by complicated valvings & junk.  So, what for other carbs is a rebuild, for a Weber, it's just a good scrub.  The primary moving parts on the Weber carb are the shafts that open and close the throttle plates.  In several places (Haynes, Pierce Manifolds) I was told NOT to touch these shafts. They are very precisely set in the carb body, and removing them risks grave damage.  If the shafts are so worn that they are REALLY leaking air, you are better off buying a new unit.  The risks of misassembling the shafts far outweigh the benefits of taking them out for a cleaning.  If they function smoothly, then give the areas a good cleaning, and hit them with some lithium grease. 

So, most of your work will be with toothbrushes and carb cleaner, rather than wrenches and screwdrivers.  There are components that you will detach from the carb, but many of the mechanisms will stay in place. The throttle plate shafts can be cleaned, checked for range of motion, and lubricated without removing them the body.  If you can do all of this with the shafts in place, then by all means leave them there.  


3 A  shopping list:

What comments
Your shop manuals  
The rebuild kit  
Several cans of aerosol carburetor cleaner I used Gumout.  It worked well and there was no residue.
Foot operated air pump with ball inflating needle You could use canned air, but the pump works just as well.  The needle creates sufficient velocity at the tip to blast through the passages.  You definitely want foot-operated.  One hand holds the part, one hand holds the air jet, and your foot pumps.
Package(s) of polyethylene gloves Carb Cleaner is NASTY NASTY NASTY.  You will want to wear gloves for this work.  Polyethylene will eventually degrade in the cleaner but they will last longer than latex  Buy several packages of gloves.  When one pair starts to fall apart, throw them away and put a new pair on.. 
Eye protection Get the goggles that create a seal against your face - not the sunglasses type.  It's not unusual for the pressurized carb cleaner to splash back at you.
A set of cheap juice glasses. get them at the $0.99 store, kmart, wherever.  They are useful to soak parts in the cleaner.  Throw them away afterwards
Wire mesh strainers Also at the $0.99 store.  I used round strainers with a depression in the center.  Their  diameter was larger than the juice glasses-  put the parts in the strainer and then use the strainer to soak the parts - it's much easier to fish them out.
Tweezers good for handling tiny parts.  Throw them away afterwards.  
Pipe cleaner, paper towels use them throw them away
toothbrushes Again, the $0.99 store. I bought a pack of 10 for $0.99.  Use them and throw them away.
Gasket Material you're very unlikely to find a pre-cut gasket.  Be VERY CAREFUL when removing the old carb & gasket and use the old gasket as the template for the new gasket.  Do not re-use the old gasket.
Wire labels use to label the fuel and vacuum hoses BEFORE you remove the carb.  This is most important with the fuel hoses
New fuel filter cartridge why not?
Lithium Grease in an aerosol can with a tube to shoot it into small crevices. It penetrates almost as well as WD-40, but it stays put.
paper CD sleeves, preferably in different colors When you disassemble the carb, have the exploded diagram next to you.  Each part goes in a sleeve with the name and number written on it.  Use paper, you can write on it.
Stapler To staple the cd sleeves together. Old part in one sleeve, new part in another sleeve.  Staple them together & reassembly is much easier.



MOST IMPORTANT:  Relax & take your time.  If you rush, you are likely to lose parts, or miscatalog something. 

Think of the process as an assembly line.  A part comes off the carb, goes through the cleaning process, and ends up properly catalogued for reassembly.  NEVER have more than one part off the carb at one time.  That way, you'll never be confused as to what it is or where it came from.  This is most important when you are taking out the jets and emulsion tubes.  It you mix these up, you am be seriously fukt.

When the part comes off the carb, put it in a wire strainer, put the strainer over a juice glass and blast the part with carb cleaner.  Use the juice glass to collect the carb cleaner fluid.  You will soon have enough in the glass to soak the parts.  Some parts will have a lot of gum and garbage on them and they will need a good soaking.  

The jets and emulsion tubes need special care.  Soak them, blow air through them, but absolutely DO NOT POKE ANYTHING IN THE HOLES.  The holes are positioned and machined to meter the fuel/air mixture exactly.  Location, diameter and angle are all very important.  If you poke things in the holes, you will probably alter diameters, or scratch a bore or something.  You might say, "But I'll be gentle."  No.  Just soak & blow through with air.  The jets and emulsion tubes will come apart, which helps in cleaning.  Again, only one off at a time lest you not mix them up.

Each part of the carb has an associated number on the diagram and the parts list.   While the part is soaking, write down the part number and the name on the paper cd sleeve.    During the soak, look though your bag of new parts in the rebuild kit.  If there is a new replacement part, put it in a sleeve. Different color sleeves are very helpful here. I used fluorescent orange and green (cool colors for hip music thieves!!)   I used orange sleeves for old parts and green sleeves for new parts. The sleeve with the new part gets stapled to the sleeve with the old part. When you reassemble the carb, you will be VERY HAPPY you took the extra time to do this.

 After the soak, scrub the part with the brush, and dry it with the air.  Put it in the sleeve.  If there is carb cleaner on the part, it will melt the plastic window of the CD sleeve.  No worries, carb cleaner will take it right off, but you don't want to clean it twice.

Some mechanisms will come off the carb and need further reassembly.  The accelerator pump is a good example.

After you have completed the disassembly, stop & take a break


Do not start reassembly until you have completed the disassembly and cleaning steps.    And, please, take a break before starting the reassembly.  You want to be rested and have a clear head when you start.  The reassembly will go quickly and smoothly.  Because you took the time to catalog the pieces as they came off the carb, you will remember how they are reinstalled.    The value of referring back to the exploded diagram and writing part numbers on the CD sleeves is that you stopped and thought about each part, where it came from, and its name.  These three things are immensely helpful in reassembly.  There is no instruction book to tell you how to put the thing together.  When you start, you will have a stripped carburetor body, and a set of CD sleeves with parts.

Screen to minimize clogging of the jets and passages.