So you just bought a used Holley at the swapmeet or from eBay, what do you do now? You don’t want to just bolt it on
and fire that beast up! Even if it looks to be in good condition you don’t know if it’s all varnished up on the inside from
old gas. You certainly don’t want to run the risk of the gaskets being dried up and the carb acting like a lawn sprinkler
under your hood. Should you send it out to have it refurbished or just go through it with a rebuild kit?
The use of the carb and overall condition will dictate which path you take; if it’s used, it needs to be gone through. If the
carb is for that “show stopper” Z/28 you’ve been working on then you’re going to want to send it out for reconditioning.
When you get it back it will look and work like brand new. I have a couple of recommendations that will do a fantastic
job, they are the Holley Custom Speed Shop at 888 465-5395 and Woodruff Carbs at
330 799-9479. Another reason to send that carb out is if major parts are worn or missing. Ok, so you determine
that used carb isn’t too worn and has no major parts missing and the finish is acceptable for your weekend warrior. Most
of us fall into this category, as even when our cars are on display the air cleaner doesn’t usually come off. Clear off the
workbench and roll up your sleeves, it’s project time!
If you have never gone through a carb before, the thought of doing the rebuild yourself may sound intimidating. It doesn’t have
to be though; all you are really doing is taking it apart, cleaning parts, replacing some and then reassembling it. It just takes
a little planning and some research before you get started. Find the list number stamped into the choke horn of your carb,
mine is “LIST-4346” and can easily be seen. Download Holley’s published reference “Carb List” from
http://www.holley.com/TechService/Library.asp
(acrobat reader is needed to view it). Look up your list number and reference what model and size your carb is, there’s
a ton of good information there, use this as a guide to insure the guy at the parts counter gets you the correct rebuild kit. My
favorite speed shop sells a kit from a local company here that includes the blue (reusable) gaskets and Holley hard parts. No
matter what brand kit you select, make sure all the hard parts are made by Holley. I’ve seen less expensive needle & seat and
power valves installed in carbs that left them very hard to tune… Here's a list that will get you started assuming you have some
common hand tools.
Proper rebuild kit
4 – 3/8” bolts, 2 ½”–3” long with 2 nuts on each.
Compressed air (an aerosol can of air used for electronics will work if you don’t have a compressor)
Carb cleaner (a large aerosol spray can is fine)
1 throw away aluminum roasting pan
A few pot pie size aluminum tins
A toothbrush size wire brush
Clean shop rags
Eye protection and rubber gloves
A large clear spot on your work bench
If you are laughing after reading this list because you have a compressor and a parts washer and buy carb cleaner in 5 gal cans
you shouldn't be needing this tech article!! Stop reading right now and start putting your own articles together and submit them
to me for publishing... The rebuild kit will come with instructions, go over them before you start and keep them handy. Thread
a nut onto each of the 4 bolts so that enough of the threads are exposed enough to go through the carbs base plate and allow
you to put another nut on the bolt. Use one bolt on each of the 4 corners of the carb; insert the bolt through from the bottom and
place a nut on the bolt. This is a very cheap but effective carb stand, adjust and tighten the bolts by hand so the carb sits level. At
this point I’m not going to walk you bolt by bolt and screw by screw through this as I’m sure I’ll miss something or your carb isn’t
exactly like mine and things will get real confising. You want to start disassembling the carb now but be somewhat systematic
and pay attention to how things come apart. Set up your workbench so you have the big aluminum pan in front of you. Use it
when disassembling the carb in case there is any fuel in the float bowls. Open up the rebuild kit and lay out the parts and gaskets
on one side of the pan. Put clean shop rags down on the other side of the pan so you can set the parts out on them as you take
them off the carb. As you are tearing down the carb pay attention to the old gaskets & parts (look at the exploded view
drawing provided with the kit so you know what to expect) and how they fit so you can identify the proper new ones as the kit
may have several to select from.
Clean each piece as you take it off the carb, if the gaskets are stuck use a pot pie tin to soak the part in carb cleaner. Don’t
soak any rubber or soft pieces you plan to reuse. Use the wire brush lightly after using a small flat blade screwdriver as a
scraper remembering carb parts are rather soft and can be damaged easily. You can spray out all the passages with carb
cleaner using the straw that came with aerosol can, use caution as the exit passage may be pointing back at you. Wear
eye protection for obvious reasons! Follow up with compressed air and move on to the next part. Take your time and pay
attention, you’ll be successfully putting your carb back together before you know it. The accelerator pump is the one thing
I always mess up on, which way did that thing go when I took it apart?. As you start the assembly, don’t get carried away
and over torque things, if a part has more than one fastener snug each and then go back and tighten each. Refer to the
factory setting in the rebuild kit instructions, the Holley tech web site
http://www.holley.com/TechService/Library.asp or find a copy of the “Holley Model 4150 & 4160 Carburetor
Handbook” By Mike Urich or any of the other great Holley reference books available. I also touched on some general settings
in my previous writings. Getting Back to the Basics refer to it also for initial
firing of your carb once you have it back together.