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Carburettors - Some Helpful Tip to Rekit Them

Some carburettors are a daunting task to disassemble let alone trying to put them back together. Attention to detail in disassembly will make it easier to re-assemble what ever carb you are working on. A workshop manual will be very helpful and the schematic in the carb kit will help as well but sometimes these are just not helpful enough. Some tips I have that may help.

Draw your own schematic of the carby. Place the carby in front of you with the float bowl closest to you. Draw the barrels & where the float is in relation to them. If you have several different linkages to disconnect, then mark them with a felt pen or similar. Make a note of the markings on your drawing to remind you where they go. As you dismantle further and feel that you may forget where a particular component goes, then mark it on your own schematic. From there write down the jet sizes & where they are in relation to the barrels. Ensure you identify the emulsion tubes correctly & note their positions. This way you won't inadvertently put the jets & emulsions back in the wrong place. Some carbies will have different threads or shaped jets that will not allow you to mix them up. Eg. A main jet will not screw into the air correction or idle jet holes or visa versa.  However in a two or four barrel carb the main jets may have all the same thread so it may be possible to mix them up. There is always an exception to the rule so that's why it is best to mark where the jets came from. As you strip the carb place all the parts in the correct relationship to each other on the bench, even the screw if that helps you. Then just clean the parts one at a time and place them back into position on the bench. Generally you will have a decent schematic included in a premium carb kit, like the FuelMiser kits. This may help you in the broad sense of fitting major bits correctly. Additional information such as float settings, linkage adjustments and helpful hints are on the same sheet. These are very helpful for setting up the linkages correctly.

Where ever there is a major gasket you need to ensure the mating surfaces are flat. This will require you to run the parts over a sheet of wet & dry paper approx 80-120 grit to ensure the surface is flat. You must use a flat surface to place the paper on, glass is a good surface. Don't wear to much away, just enough to get the surface flat. Some carbs will have a small bead cast into the housing around critical gasket areas. DO NOT rub them completely off if at all possible. But if you have to rub them off to get a flat surface then you have to. If the parts are badly bent, then a low heat needs to be applied to the part and the part will have to be straightened. This may require the use of some sort of press or possibly can be done in a big vice with suitable jigs. Do not over heat the part as it quickly turns to mush. Maybe this little task might be best left to a professional carb builder to do for you.

You must have compressed air available and a good carb cleaning solution also is required in most re-kitting jobs otherwise you will probably waste your time.

Use a small amount of rubber grease or vaseline to install 'O' rings onto tubes or fitting that will be pressed together. This will stop pinching of the seal. Some carbs have very small 'C' clips and are lost very easily. These are hard to get without purchasing a complete kit. Hopefully you will get a few in the carb kit.

Handle the float carefully. If you damage it it may soak up fuel which will make it heavy and therefore will not be able to control the fuel level. The consequence is uncontrolled flooding of fuel into the engine.

Re-assemble the carb in the reverse to dis-assembly unless you found a better way while pulling it apart.

In summary, mark where everything goes on your schematic, ensure the parts are clean and surfaces are flat.

One final point after the carb is refitted. If your ignition timing, ignition system or engine is not in good condition then the carb cannot be adjusted correctly. Fix the problems then adjust the carb.