Boy would I love for someone to give a step by step with pics on the rebuilt carb needs. This is one area I need help in. Hint Hint !!
Unscrew the dashpot and remove the piston making sure you don't damage the edges or lose the spring..it's big so there's little chance. Polish any varnish buildup off the piston ahaft and reassemble check piston for free movement by using the lifters to lift it and let go it should fall with a decided "clunk". Then fill the dashpot with SU dashpot oil every fortnight (two weeks) and that's it for another decade. Unless you actually change the screw settings and then you will have to rebalance if you have multiplr carbs. You were inquiring about SUs right?
SU's are covered under parapsychology, not tech. Carb rebuilding stuff: The less experienced you are, the more you need to organize. Work in a tray of some sort so if something unexpected rolls out you have a chance of finding it. Have some sort of compartments such as microwave trays or a desk organizer available--you should have trays for bowl, external parts, and each barrel of the carb to separate parts by home territory unless you are really experienced on that type of carb. Try to remove each gasket intact so you can verify match with new one. For each layer of carb assembly, that is upper air horn, main body, etc. draw a rough outline similar to the gasket outline for that part, mark it clearly fore-aft-top, and punch all the screws through the paper in their proper positions. This is because many carbs have more than one length of screw at each level, and figuring out that the long one doesn't go into this hole because it will crush the float is not something you want to do. Again, the less experienced you are, the greater the need... As a beginner, you will likely fixate on the complexity of the innards. While organization and sketches are important here, you will likely be able to figure out placement of internal parts from obvious clues like hole sizes and the drawings in the instructions. Where you will be driven mad is on the external linkage on relatively recent cars with automatic chokes, elaborate fast idle and venting systems, and so on. Sketch each of the linkage rods with bends drawn recognizably, sketch in which of the several holes in each gadget the rod enters, and whether it goes through from this side or that. Linkage can be complex on sixties and seventies cars, and manuals are often inadequate here because of variations between related models. Unless carb is severely worn, most of the real work is in cleaning the soft metal castings. Few solvents really do the job, and the ones that are most effective are expensive, toxic, and so smelly your neighbors will call the EPA. Here's my drill for "No divorce carb cleaning at home": First, get rid of soluble grease and varnish by brushing in mineral spirits or other such solvents. Strong detergent solution and lots of hot water then blows away dirt. You are now face to face with the real challenge: Blackened deposits in the throat, white stalagmites and pits in the bowl (and hidden passages beneath the bowl) from water accumulation, and mystery grunge that laughed at your solvents. Some of this is important functionally, other bits of it will leave even a well done job looking like crap. Get hold of a variety of round and straight bristle brushes--bottle brushes, tooth brushes, gun cleaning brushes, etc.* Immerse casings in cheap gallon jug generic vinegar. Stick around--you DON'T want to marinate overnight because your carb will be gone by then. After a bit, attack grunge with whatever brushes will fit, and scrub. Rinse, eyeball, and repeat. This will get parts down to bare mystery metal, even removing carbonaceous stuff in bores. Next, perhaps you have severe white deposits/pitting in bottom of bowl from water. If you do, go read the safety warnings on all the toilet bowl cleaners at the grocery and buy the scariest one, which should mention HCL on the lable somewhere. This is strong enoug to clean, too weak to blow through your carb as you watch. Fill bowl to level of crud, tilting and shaking to be sure air bubbles out of those passageways beneath the floor--they are your real concern here. Soak for a few minutes, rinse thoroughly with blazing hot water, repeat until white is gone and then a bit more til you are morally certain hidden areas are clean too. Do not leave room or answer phone--if you get distracted during the HCL step you may see your own shoes next time you look into the bowl... Castings should now be clean metal. Be sure all acids have been flushed out. Small brass bits each go into something like a bottle cap of fierce spray cleaner, then a SHORT swim in ammonia for discoloration. If probig is needed, use plastic or wood in apertures--a scratch in a jet is significant. Reassemble, referring to your sketches and pulling screws and such from their holes in your organizes. I believe in putting even clearly interchangeable parts into their original locations with old machinery. Adjustments (idle speed, idle mix screws) should go to original positions--you should have noted positions (turn mix screws in fully for count before removing). Ofttimes, you can clean their positions and passages fully without disassembly here. As you prepare to assemble each casting, verify each passageway with a squirt of spray carb cleaner through each hole. Be wary of squirt exits that seem inadequate... Carb should now be redy to go, and there should be naught but discarded gaskets left in your tray...
[ QUOTE ] SU's are covered under parapsychology, not tech. [/ QUOTE ] Well, since you know so much about the subject, how do I get the Coffee out of my nose and sinuses that got there from laughing so hard????
"Well, since you know so much about the subject, how do I get the Coffee out of my nose and sinuses that got there from laughing so hard????" HCL toilet bowl cleaner, flushed well with ammonia--oh, you weren't going to USE that nose again, were you? Next week should be "parapsychology week" on Hamb--I'm sure there's lot's of good Voo Doo and interesting superstition on here too... The SU's remind me of a line I saw in a car mag once... "Since I was restoring a British sportscar, I was used to dealing with blacksmiths, wizards, and charlatans..."
[ QUOTE ] Next week should be "parapsychology week" on Hamb--I'm sure there's lot's of good Voo Doo and interesting superstition on here too... The SU's remind me of a line I saw in a car mag once... "Since I was restoring a British sportscar, I was used to dealing with blacksmiths, wizards, and charlatans..." [/ QUOTE ] He must have been refering to the wizard prince of darkness, Lucas And I guess that was short for blackface Smith's guages? And the charlatans are the makers of the body rust proofing! After mechanical tech week maybe æsthetic tech week and then the esoteric tech week. That qwould be a week of how much dry ice is required to shock a hail stone dent into submission and how many CB400 carburetors a 327 SBC needs to breath properly.... PeteJoe, What kind of carb you want to be learned on?
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