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I got the car running and broke in, so now it's time to tweak the carb. I know that I need to begin with the float adjustment followed by idle mixture adjustment. No where have I found a good article detailing the float adjustment process. As a matter of fact, many times have they contradicted themselves and sometimes contradictions within the same article.

Apparently there is a difference in side hung floats and center hung floats. First of all, how do you tell what you have? Secondly, the method of float level adjustment varies based upon whith float type. One level increases with clockwise turns and the other increases with counter clockwise turns on the adjusting nut.

First, here's some specs on my car:

Stock 302 w/ a "little hotter" cam (unknown specs), performer 289 intake, hooker headers,

Holley 4160 600CFM vacuum secondary (80457-2 0291)

The carb was purchased at a swap meet and was supposed to be a factory bench test model. It was in good shape and appeared to be hardly used.

I bolted it on and the engine and it runs, but seems to be VERY rich and idles like it has a monster cam in it.

Here's what I have don'e so far:

With the engine off, I Opened the sight plugs on both bowls and fuel gushed out, obviously indicating that the floats need to be adjusted down. I loosened the retension screw and fuel sprayed out temporarily then stopped. It looked like the adjustment nut was all the way screwed in, so I began turning it counter clockwise. I noticed that when doing this, it wasn't screwing out of it's hole, but instead, it tightened back up on the retension screw. Apparently, this nut isn't threaded into the body of the bowl.

So, now to my question: Simply put, how do I adjust this darn thing.

1. How do I determine which bowl type I have?
2. Which way do I turn the nut to lower the fuel level in the bowl?
3. Is there a factory starting setting I can put it back to, as I didn't monitor how many turns I gave it initially?
4. What is the adjusment nut turn to bowl level ratio (how many turns to move level per inch?


Any help would be appreciated.

Thanks,
Glenn
 

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On the fuel level adjustment.

I don't know that all 4160's are the same...but mine has sight plugs on the passenger side of the carb. The correct fuel level is just even with the bottom of the plug hole (when removed). You can buy a set of clear sight plugs to replace the solid ones for about $5.00 that make it much easier to check your fuel level. I just shine a light at the clear plug and give the car a little bump with my hip or thigh. As the car rocks you can see where the fuel level is through the sight plug.

Phil
 

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I have the same carb as you. It's a side hung float carb. To tell the difference by looking, a side hung float has the adjustment screw on the side of the top of the bowl...a center hung has the adjustment screw in the center of the top of the bowl.

Just use a big screwdriver and a wrench on the nut. Hold the wrench on the nut, and losen the screw. Take off the side plug on the bowl. Turn the nut until the fuel level just barely starts to trickle out of the side hole. Tighten the screw on top of the nut. Put the side plug back in. Thats it!
 

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http://www.holley.com/HiOctn/TechServ/TechInfo/pic4.gif

HTH
 
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