I've got a 1966 122 sedan I'm restoring, and have a mechanic who's itchy to get his hands on it. I just paid him a hefty bill to replace the head gasket and exhaust, but have heard I can probably clean the carbs myself. The car had funky old gas in it, and the car's not running well without the choke out. I'd rather save my money to have him pull of the hubs and work on the brakes, so can anyone give me fairly detailed instructions/tips about cleaning out my carburators? (but not rebuilding them--they were rebuilt 8 yrs ago, right before the car went to "sleep"). Thanks--hfav

Thanks to Phil and Walrus3--you're both extremely helpful and knowledgeable, and I appreciate the input you gave for my engine paint (I painted it--it looks great), but I have a few more questions on my B18 carbs. Walrus3--I opened up the float valves, and the gas in there, as well as the interior of the chambers, looked pretty clean. Should the funky old gas that was running through there since we started her up have crudded up these valves as well? Or does this indicate they were recently cleaned? The mechanic drained the old gas, ran some air through the tank, and put some new gas in, so did that do enough to make it look as good as they did in there? Phil, what was the rosy-pink fluid I poured out of the shaft (cylinder) that housed the damping plunger? It sure didn't look like oil, but what else could it be? I cleaned out one carb, but for the car's neglect I expected something worse than a thin film of black in the Q-tips. That black was only barely evident with my bare eye as a dulling of the metallic color on the inside of the piston (?). Is that as bad as it should have been? Lastly, my mechanic is reccomending rebulding the carbs while I'm opening them up to clean them, but that was done 8 yrs ago--immediately before the car was never driven and put to "sleep." Is this worth doing again now, and if so is this something I could do myself (he wants to do them)? As you may guess, I'm new to working on my car, but am very game to learn and do it "right"for those things I can.

The rosy pink stuff was probably automatic transmission fluid. You'll get better throttle response using motor oil.

Not everyone has the same idea about what a carb rebuild consists of. Check that the throttle shafts fit tightly in the bores through the carb bodies. If so, there's probably no need to rebuild anything. If you can rattle them around because the holes have worn oval or the shafts are worn, that will need to be corrected or the carbs will never tune right.

If I read it right it looks to me like Phil didn't say much of anything
about the float chambers, which is where most of my problems have been.
Take the top off each float chamber and empty the chamber any way you can
(I sometimes use a turkey baster or other big eye dropper)
There may be gunk in the bottom, especially in the little rectangular box
that leads to the jet connection. Clean that out with Q-tips or whatever
way seems best. Dirt in the jet will NOT help!
Take out the float and the float valve and blow through them to make
sure there is no gunk there. Be sure the valve is screwed back in the
chamber lid good and tight. (I've had them vibrate loose and flood)
Put the float back in and check the float level - should be 1/8" to 3/16"
from the top of the float to the bottom of the lid. Mine do better closer
to 3/16". Put it back together and hook the fuel lines back up.
--
George Downs, The "original" Walrus3, Bartlesville, Oklahoma

Remove air cleaners. Remove choke cables from both carbs. Working on one carb at a time, so there's no possibility of swapping parts, undo the three screws that hold the dome to the carb body. Reach through the throat of the carb and hold the piston so it lifts out with the dome -- lift dome straight up, being very careful not to dink the needle in the piston. Keep the piston in the dome for now.

On a workbench, unscrew the cap at the top of the dome and pull out the plunger that comes with it. Pour out any old oil or whatever is left in there. Now remove the piston and spring that's behind it.

Clean everything with carb cleaner, paper towel, toothbrushes, Q-tips, etc. Do NOT attempt to polish anything with steel wool or use any abrasives at all.

Clean up what you can get to on the carb body in a similar way, and reassemble except for the cap/plunger. Make sure the piston is free to go up and down easily and that the needle does not rub inside the jet.

Repeat for the other carb.

Pour a small amount of motor oil in the hole at the top of the dome, install the cap/plunger, and lift the piston all the way up. Some oil should come out the vent hole in the cap -- if not, add a bit more oil and repeat until it does (have a rag handy). That is the correct fill level for the oil. The piston should now give up a fair amount of resistance pushing up, and it should drop right back down all the way with an audible thud.

Repeat for the other carb.

Hook choke cables back up.

How to synchronize and tune SU carbs