1981 Holley 1850-3 Questions

[Creedmoor]

Getting ready to do a full rebuild on my old (1981) Holley 1850-3, which I think is essentially the same as a 4160. I have a few questions so far:

First, how much “wiggle” is OK on the secondary shaft? I assume if it is excessive, it constitutes a vacuum leak. I’m guessing to fix it one would need to replace the little white Teflon sleeves/bushings in the shaft bores. The butterfly’s are screwed on the shaft and “staked”. Is there a preferred procedure to get the shaft out and back in successfully?

Second, the electric choke housing has an externally threaded “pipe” coming off the lower rear area (see pic). What is the purpose of this? What would be screwed onto it? Some sort of cap? Carb has been running fine for over a decade like this but it just seems odd/not correct.

Appreciate any guidance or wisdom you all would care to provide. Thanks.

 

[TT5.9mag]

The pipe connection is for an old school choke stove inlet. You have an electric choke so it’s not used.

The staked butterfly screws I have had success grinding flush with the throttle shaft and removing them, when reinstalling I use red loctite and I stake them with a sharp punch.

You are absolutely correct about the excessive play in the throttle shaft. It becomes a problem when air passes past the shafts and you can’t get the engine to idle down. Replacing the bushings is the fix. Holley sells them by themselves but also has a part number for a throttle shaft service kit that’s about $50 and comes with everything you’d need.