oops ,, idle hands cause much trouble

[BadaBing]

In order to have some "projects" and to not be cold while doing them, I brought my carburetor and distributor home to the work bench to spiffy up for spring.
The distributor clean up went very well so I turned my attention today to the carb. Thanks to a previous thread about poor idle performance I learned that I had an idle port above the throttle plate, which we nicely clogged. a little work with a bit of monel sizing wire fixed that. Then I turned my attention to the floats, needle valve and jets. Floats were very our of wack, with the closed measurement being 1 3/8" vs 1 5/32. Most other passages and jets were clean and seemed fine, until I came to the idle jet.

The idle jet was badls stuck in its threaded hole, after working at it a while I managed to turn is about 1/2 turn out before the soft brass or bronze gave up and I lost the ability to use a screwdriver. Using a small reverse drill I drilled out the center of the jet in prep for an easy out removal. BUT even the easy out will not budge it. Im considering retaping the hole in preparation for a new idle jet. Does anyone know the tape size and pitch required?

Great, I just checked the online catalog and it seems that an "idle jet" alone is not available, anyone have a spare lying about?


Thanks

[hanleyclifford]

Bill - I have one I could send you. I'm concerned about the necessity of re tapping that hole. Seems to be an 8-32 tap.

[BadaBing]

Hanely
Thanks very much.
I did manage to find a tractor company that "claims" to have these jets in stock for under $9 each. I was worried, when I saw they are not listed on the MM online catalog, that they just are not available anywhere.

I'm confident there is enough there to retail as I did not drill it so much to reveal the threads themselves. I thought the easy out would work but what is left of the old jet is stuck fast in the body.

Do you still have my address? I'll dig your up from our last exchange and mail you a contribution.

Thanks

[hanleyclifford]

Just an Idea

Bill - In the olden days when aluminum case transmissions were still being rebuilt in the dealerships we had a nasty lye bath that we used to clean and strip housings. I wonder if that approach might help separate the brass remaining in the housing? There isn't much room for error seating an 8-32 (if indeed I am correct about the tap size.).

[Dave Neptune]

Bill, when I get back to work I will dig up my contact on Zenith parts. I have not used them for a while however I think they're still around. I just can't remember their name. They are in the SF area of Cal.

Dave Neptune

[BadaBing]

Thanks .

It would seem a shame to trash the carb over one little little jet. Then again, the main reason I pulled it apart was because I.was not satisfied with how it idled.
Couldn't make her idle under about 1000 rpm under load and it often would die if I pushed her from partial or higher throttle to idle to quickly, like when pulling up to a dock.

[JOHN COOKSON]

Bill
Have you ever had water in your gas that made it's way into the carb and caused the brass to corrode to the aluminum?
If so did you get the watered gas under control? If you have watered gas that is the root problem and it needs to be corrected.

TRUE GRIT

[romantic comedy]

What would be the chance of filling in the jet/hole with something and drilling it out to the appropriate size?

Is it just a jet, or does it have the holes horizontal?b (emulsion tube?)

Could it be filled with solder or JB weld? Something else maybe?

[BadaBing]

John
I had quite a battle with water and gas a few seasons back. It's why I tend to be outspoken 're flushing a gas tank. I solved the source, eventually. It took replacing the fill cap. Since then I have not seen any sign of the water problem. But that could be the regional value of th I frozen in place jet. Thank.

RC. I was thinking the same thought, if it comes to that. But I think I can probably chase the threads out once we determine the appropriate tap. According to the exploded view it is just a jet so I probably haven't killed it.

[Al Schober]

Bada,
I think I bought some Zenith carb parts (including the idle jet) from a place selling parts for Gravely tractors. As I recall (CRS kicking in) their prices were quite reasonable.

[JOHN COOKSON]

If all else fails and it looks like write off try heat + torque + impact to remove the idle jet. Something like heat the area up toasty warm and then tap on the easy out while you twist it with a wrench.

TRUE GRIT

[hanleyclifford]

Before attempting to remove that idle jet (or any jet for that matter), it really, really pays to take the time on a bench grinder to modify a screw driver to make a perfect fit in the jet. Also, it is not necessary to crank the jet into it's seat - just a light twist to seat is all that is required; trust me, the jet will not fall out.

[JOHN COOKSON]

A Couple More Thoughts

If the jet comes loose but is still tight twist counter clockwise and clockwise as you remove it. This will help loosen it. This sounds counter intuitive but it does work.
After you get the jet out I hope there is enough aluminum left to tap. Aluminum is the sacrificial metal with brass. It may be necessary to fix the new jet in by some other means. Maybe epoxy? I don't know if epoxy is fuel poof or not.

TRUE GRIT

[BadaBing]

All great advise. But. Even though it was a correct screw driver size and I thought I was careful I still managed to twist off the top portion of the jet. So I drilled it out to almost the threads.
N e x t step is to chase the threads

[hanleyclifford]

Bill - I need to know which type you have (from the picture). BTW, thread seems to me more like 8-32, which I do not have.