Tell Me Your Zenith Carburetor Secrets Please!

I had some stuck and soaking them in 50/50 ATF and acetone loosened some of them. Had to drill some out though. Like the idea of a piloted drill.

Steve
 
Like Kurt I use a screwdriver ground for a perfect fit, and if that doesn't get it, then I also I use a propane torch and heat the cast iron next to the well until it's a dull red then run cold water over it. Sometimes it takes a sceond heat and quenching, but so far it's worked by the second heating and quenching.
 
Heat it up and hold a candle on it, the wax will melt and wick into the threads, you may have to give it a few cycles.
 
Hi Vince, Sounds like you have tried just about every method both commonly and uncommonly used. I have not done that many Zeniths and never had your problem, but I have done threaded brass hardware removal in cast iron and zinc die castings, etc. and I prefer to first use one of the easy-out taps followed by a left-handed drill bit to the minor diameter of the threaded bore if the easy-out does not do the job.
There is a new product out there which is a combination of the left handed drill and easy out wedded together, but to date I have not used one of these. There is also EDM (electrical discharge machining) which is commonly used to remove broken taps from castings and machinings,etc. but here you are talking about an expense I am sure no one would consider for a humble Zenith carb. Let us know what you find works best for you.
 
Perhaps a left handed tap to thread the inside, remove tap and insert the matching LH bolt to turn. Drop in ball bearing(s) or piece of rod below bolt so it grounds against that rather than trying to advance beyond end of threads. Using tap or EZ out to turn sounds to me like the start of an even worse day.
 
I use a little heat and then I try to tighten the well first. Sometimes, the tightening movement is all you need to free a stuck well or GAV seat.
If that doesn't work and I kill the slot, I will then drill out the well close to the thread size and use a tap to clean the rest of the brass away. Be careful drilling as a drill will bite quickly into the brass and could cause damage.
 
Truth first. I've buggered a lot of brass in my relatively short time as a Model A "restorer."
More truth: My last carb "restoration" resulted in a beeeutiful Zenith II with an Easy Out snapped off in what's left of the cap jet. (I had chased the threads and was screwing in a pdg jet in when it broke, starting the disaster).
My fellow RESTORER, who has earned the capital letters, has rescued me in the past with HEAT. Like Tom W said, above, John also says to heat the cast iron to dull red. Then let 'er cool. Then use your favorite penetratant. Then, if you need to, heat 'er some more. Take your time and apply plenty of propane! It will come out.
Caveat: Busted off steel easy outs are a much thornier problem.
 
One of the neat tricks (and I think that this was Paul Moller's) is to put the top onto a jar and hook up a gas line. You can actually SEE the gas level in the bowl, and it's less work to change washers to adjust it, because you don't have the whole thing assembled and installed.

Steve
 
McMaster-Carr---

#2584A15 left-hand plug tap. (Also available in taper and bottoming.)
Don't see any left-hand shoulder bolts there. You could roll your own from a 2" Grade 8 LH 1/4-20 bolt #90211A230 and a spacer tube maybe 1-1/2" long.

Joe
 
Someone mentioned a hollow ground screwdriver. I got a set of gunsmith's screwdrivers and they have solved a lot of problems for me.
 
Modeleh makes a good point. At work we use bee's wax on exhaust flange bolts as a last resort. (1800 plus degrees) It is amazing how well this method works...
 
Chris in CT said:
There is a new product out there which is a combination of the left handed drill and easy out wedded together.
Click to expand...

They have been out for years. I used to sell them 15 years ago.

ALD6207P.jpg
 
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