Tech: A Dummys guide to Discovering and Rebuilding a Holley 94 6x2 setup For some this is Tech / How to, for some it will be a snooze! I am no carb expert, in fact carbs drive me crazy, but I am a firm believer in the more the merrier! Id appreciate some feedback on this, as its a rebuild at home over thanksgiving weekend (and then some) by me with limited tools and enough knowledge to be dangerous! I generally think of myself as the dummy when it comes to knowledge on the hamb. So if I have not done something I should have or vice-versa fire away (I have my flame retardant undies on!) Each image is a link to a fullsize image. When my car was really coming together I looked at the carbs, decided they were ok (I was just to eager to be able to drive it) and then fire in the hole, whoa, wait no really, I had fire coming out of the center passenger side carb. Hmmm, so I did a quickie rebuild of the 2 center carbs and tried again. I could get it to run only if I kept pumping the pedal. It wouldnt idle, had fuel leaks from the throttle shafts and other random places, backfired once loud enough to make my ears ring and vision go funky (at that stage I quickly shut the garage door and called it a night!). So I looked into them a bit more and realized that I cannot rush into driving the car and given that everything else is rebuilt or new, skimping on maybe the most complicated parts would not be wise. Here is what I started with - oddly enough it looks almost the same as what I finished with ! So lets rebuild them. What I knew going into it I have 6 matched Holley 94s (2100s) on a Weiand Dragstar manifold. I knew my accelerator pumps in the middle 2 are suspect (search my posts). It is a progressive setup, running the center 2 as primaries and the outside 4 as secondary (the outside 4 have a straight linkage). I dont like the linkage for the middle carbs and will redo it - basically I dont trust it not to stick open. I had fuel leaking out of 3 of the throttle shafts and they are all a little sloppy. I have one secondary carb that just pours fuel down its throat. I have one primary that doesnt appear to do much at all now. I dont know what is in the carbs (jet sizes, power valve sizes all unknown). I am not going to change anything that I dont know enough about at this stage. I can do that once I get things running and learn some more I will go through one primary and one secondary. In prep I had purchased six rebuild kits, six new .003 oversize throttle shafts, two 2x2 progress linkage kits (to modify my existing primary to secondary linkages) and a bunch of return springs. First I removed all the carbs and laid them out in order. For working on each carb, I divide them up into the 3 main parts top, middle and bottom PRIMARY CARB Take the top and base apart so you have the three main components. For my carbs that is removing the connecting rod from the throttle shaft plate to the accelerator pump rod and undoing the screws on the top and the 3 screws for the base (2 on top and one underneath) The TOP: Teardown: First thing I notice after taking the top off this carb is that the fuel bowl was bone dry. The shut off needle is stuck and when I free it it tends to stick closed. Take the float off it just has a needle holding it in place. Then unscrew the shut off valve. Assembly: While it is bare I run air down through it. I also give it a light sanding my truing device (a piece of sand paper taped to a flat table). Then I lay it ontop of the middle when the middle is completely apart and has also been lightly sanded. (When I am happy that the top and middle do not have to much air gap I put them back together.) I replaced the fuel shutoff with the one in the kit. The one I removed is a metal needle, whereas the one in the kit is a metal rod that pushes a rubber seal. Then I set the float level to 1.25 inches. Dont let your brain fool you, the gauge in the kit has 32s of an inch and the 4 on the gauge is actually 1.125 inches. I say this cause I did this on the first carb and had to take it apart again when I did the second one and had a doh realization. ** Notice my carbs do not have any chokes on them. They have been replaced with a bolt. The MIDDLE: Teardown: A bit more complicated than the top. First I removed the accelerator pump and rod. Then took the clip and spring off. For this accelerator pump I replaced the cup with the blue synthetic one in the kit. Next the underside. This is where the power valve screws in. Notice mine has a plug. Still remove it so we can clean things up and put a new washer under it. If you had power valves you would replace them. Power valves is something I am unsure of, I may need to put them in the Primary carbs not sure yet. Then I removed the plugs on the outside of the fuel bowl area so I could get at and remove the main jets. My main jets are both 51s. Check to make sure they are both the same size. Then you can remove the nozzle bar / accelerator discharge nozzle clamps. Remove each nozzle bar and unscrew the jet from each one. Then remove the discharge nozzle and there should be a needle valve in the tube under that nozzle (tip the section upside down and it should fall out). Oh one thing I did not mention or do is remove the ball bearing that lives at the bottom of the accelerator pump well. If you look down there you should see a retaining clip and a ball bearing underneath the clip. (I probably should have removed them?). Assembly: Alright at this stage I put all the parts to be cleaned in my basic but semi effective cleaning device (yep its a pot and a tin can with holes in the bottom), shake it about, leave it overnight whatever floats your boat! Now I do the truing on the top and bottom of the middle section. After that is done I wash the middle section, blow air through all the holes and put it back together. Nothing really special here, just replace all gaskets/washers with new ones. I put some oil onto the plunger and the plunger arm when putting them back in. (see pictures below. I have showed both types of accelerator pumps - the longer and correct one with the synthetic cup and the shorter leather cupped one that comes in the generic rebuild kits. The leather cupped one gets soaked in oil and push out the edges with a screw driver when soaking so it fits more snugly (search my previous posts - thanks Bruce!) I run compressed air through all the jets before reinstalling them and through all holes in all the nozzles (basically if its a hole it gets air blown through it). I also used a babies bottle nipple cleaner (I had to qualify that one!) to clean down into the accelerator needle area and give it a visual with a light to make sure it doesnt have anything stuck down there that could get under the needle. I also put the nozzle clamps into the vice and straighten them out (edited: Dont do this! I found out when I put it all back together that one nozzle was loose and wasnt squirting properly. You should leave the bend in them and the bend goes down towards the nozzle - so install them like a u and not a n!) The BASE: Teardown: I am replacing the throttle shafts, but I didnt give much thought to the throttle plates. They seem to shut and seal ok visually, but they may get replaced. Anyway remove the idle screws and springs. Then remove the screws from the throttle plates they are bent over on one side and you would not expect to reuse these. Then push out the throttle plates and slide out the throttle shaft. Remove the plate on the end of the throttle shaft that connects the shaft to the accelerator arm (that then attaches the accelerator pump). Make sure you keep the washer that is underneath this plate. Now I ran the base unit over my truing device until I was happy with the fit of it to the middle section and also happy that the base was nice and straight for a good seal the inlet manifold.