Holley 4bbl rebuild

[cazsper]

How long can a carb sit before it needs a rebuild? When I bought my '73 Mach-1 in 2011, the car hadn't run in about two years. I tinkered with it on and off for a year before it was driveable (rewire the engine compartment, new fuel tank,, fuel pump, new fuel lines). This past week I just changed the plugs, wires, coil, cap and rotor. It certainly runs smoother than it was but I think it still needs new points.

Anyways, I was looking at the carb. It looks ok, but I know it has sat for a long time without running. When I did first get it running, the gas was really bad (old gas and a rusty tank). I assume all that garbage would affect the carb, right?

Also, the guy I got the car from removed the choke and choke plate.

I am just wondering if I should have the carb rebuilt. If so, is that something I can do myself? Is it very involved?

 

[oh dam]

i think itll be a safe bet to rebuild it. Because youl just be trying to fix whats broke and it wouldnt run right if its all worn out and such..and after time sitting with gas in it the gaskets(if it has any) will definitely dry out

 

[cazsper]

That's what I was thinking. Have you ever rebuilt one?

 

[Jeff73Mach1]

I've done several Holleys and a Carter AFB (Edelbrock basically), though truly what I and many others do isn't a rebuild, just a disassemble, clean, replace gaskets, reassemble.

I would remove the fuel lines and then the float bowls and look for any signs of rust/dirt/contamination/varnish. Check the floats for leaks and make sure they are adjusted properly. If the bowls are clean, spraying the inside with carb cleaner and reassembling with fresh (Holley brand only) gaskets may be all you need.

Changing jetting, accelerator pump cams, squirters and other bits and pieces is a much more complicated explanation and beyond my ability to explain here (or perhaps anywhere)

Some Carbs with high mileage will have wear to the throttle shafts which require bushing the holes and unless there is a reason to keep a particular carburetor, I think those are best replaced with a different one.

 

[droptop73]

If a Holley gets "dried out" a rebuild is in order. A Holley is one of the simplest carbs to refresh. If you have access to an ultrasonic cleaner take advantage of it.

 

[oh dam]

That's what I was thinking. Have you ever rebuilt one?

nope not that skilled yet lol

 

[cazsper]

Some of the shops I asked, a rebuild can be almost as much as a brand new carb.

 

[mustang7173]

Cazsper,

I have rebuilt many of the Holley carburetors with modest success in adjusting and running well. One has to wonder that with the internal chambers and vacuum ports in the main body, it would leak due to the constant heat and cold that eventually cracks internally. Thus, there is no way to fix that problem. So, I have pretty much chucked all of my older Holley's in favor of new out of the box carburetors.

I have some colleagues who have, hold on, I know, a Chevy Nova with a hot 350 engine. They went from a Holley to the Professional Products projection fuel injection system and Man!, What a difference in made in sound and general running of the engine.

Professional Products website:

http://www.professional-products.com/

We all do have budgets! So, this is just FYI.

mustang7173

 

[wwhite72]

You didnt mention if it is the original carb?

 

[Manu Mach1]

Hi,

I opened my carb, Holley 4V double pump, was afraid about, but at least was very easy, not too much parts in it. The most difficult part was to clean it correctly, gaskets were difficull to remove. Keep an eye on the kit you need for your carb, there are several ones and you need the correct kit with correct gaskets.

Then to tune it, on Holley's site everything is there to make it working. Just not agree to open some screws to adjust the fuel level in the bowls while engine is running.