Postby Workshop Help » 17 Dec 2014 12:29
While we sympathize with your desire to start castrating components off the car, the actual cause of your plight isn't being addressed.
Let's address it first before you drag out the meat cleaver. Your problem originates in the carburetors.
Please start your investigations by perusing my article in The Workshop Manual on removing the float bowls on your Z-S carburetors. You will not have to remove the entire carburetor from the engine, only the float bowls. After reading the article, read it again.
There, now with knowledge poured into your head, proceed to order two, (2), float needle valves and two, (2), float bowl gaskets from your favorite parts vendor. Once the parts arrive, then and only then should you venture forth to the garage to begin the repair process.
Okay, the parts are here. Start by removing the air cleaner assembly. As it is summer in your neck of the woods, have a strong fan blowing over you and the work area to ventilate the errant fuel vapors. Unplug the brown electrical wire to the alternator to minimize a fire ignition hazard, and/or disconnect the positive battery cable.
With the carburetors exposed, observe the mouth of each unit for evidence of fuel. If one is 'wet', start by removing that float bowl as noted in the articles text and photos.
With the bowl gently removed, is the fuel in the bowl very near filling the bowl? If so, either the float needle valve is deteriorated, or clogged with debris preventing the needle from fully seating, or the float level is improperly set. Also, is there a load of debris in the bottom of the float bowl? A 'Yes' answer to any of these queries will mean you've found the cause of your problem.
Next, using a 6" ruler, measure the float level distance from the bottom of the float to the edge of the body flange. The official workshop manual dictates 5/8". I use about 11/16" just to keep the fuel level a bit lower in the bowl to reduce bowl seepage.
With the float level set, remove the float and pin to access the float needle valve. After it's removal, rotate the valve several times to see if you can make the needle stick, either in the up or down position. Given the mileage and age of our cars along the inability to service the valve components, replacing the valve is the wiser option. Be sure to manipulate the new valves needle to verify it's motion is free. Install the new needle valve and recheck the float level, correcting for any variation.
Clean the float bowl and using a sheet of super fine sand paper on a piece of glass, gently grind the mounting flange of the bowl to achieve an even mounting surface. The effects of prior over torquing the six screws and heat can warp the sealing surface of the flange. Clean the bowl again to remove the sanding dust.
With the new bowl gasket, reinstall the bowl on the carburetor. Now, wasn't that fun? Let's prolong our joy by repeating the procedure on the other carburetor.
Some will say to always replace the bowl plug O-ring. Others will say, 'If it ain't leaking, leave it alone!' I will leave this issue up to your discretion.
Reconnect the brown alternator and/or the battery cable.
Finally, we inquire as to your type of fuel pump. Is it the mechanical item or is it an electric pump? If the pump is an electric one, be sure to have a fuel pressure regulator installed and the pressure setting at no more than 1-1/2 PSI. I run mine at 1 PSI. Also, at least one fuel filter needs to be placed in line between the pump and the carburetors.
I use two filters on my car. One filter is on the line twixt the gas tank and the electric fuel pump with the other before the fuel pressure regulator. I intend to keep my float bowls as free of debris as possible.
Fire up your engine! Is it leaking still? If not, sew the air cleaner assembly back in place and chug on down the yellow brick road for a prolonged test drive to seek out your next adventure of Life.
Mildred Hargis
