Tillotson X Drain Plug Repair?

[jchochole]

Hey guys, I bought a Tillotson X carb and my drain plug is stripped out. Before I give up on it, has anyone developed a solution on a repair? The darned carb is rebuilt and nice except for this one issue.

Thanks,
Jim

[wbedwards]

can you drill it and tap it for a slightly larger plug?

[jchochole]

I wasn't sure if I could get a larger plug- is the Tillotson style plug a universally available item?

Jim

[Brian T]

There is not enough wall thickness to go for a larger plug, using a longer plug will block off the passage from the GAV, who ever rebuilt the carb forgot to inspect all the threads, the first thing to do before attempting a rebuild.

[abachman3]

Can you just chase the threads with a re-threader?

[jchochole]

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I may try that but I don't think there are many solid threads left; I ended up hand-turning it in as tightly as it goes and used Permatex gas sealant.

I think I'll sell it off for someone on a budget because the entire carb has been fully rebuilt and even as heli-coils for the mounting screws- just has this one issue with the drain.

Anyone need one for a back-up?

Jim

[ModelAMike1930]

Why not try laser bond, Its the plastic cement activated by UV light.

[Big hammer]

Tilly carb is aluminum yes? How about tig welding the hole and re tapping !

[katy]

Tilly carb is aluminum yes?

I thought they are zinc?

[Brian T]

Jim,
Do you suppose the rebuilder will take it back? There's no telling what else is wrong with it if you sell it at least disclose what you know.

[Tom Wesenberg]

If you clean and tin the brass plug that might be enough to make it hold tight.

Use good electrical solder, and not the no lead hard to bond junk.

[johnbuckley]

Hmm, maybe I'm a worrier but it is just above the exhaust, I've got a feeling there is just about enough metal to go one size larger- you may need to look at metric sizes, I seem to recall doing it once....but.... ??? price of new carb vs insurance for replacement car?? Like Brian T suggests it ain't mechandisable quailty unless you bought it knowing that fault.

[Tom Endy]

I am not familiar with the Tillotson drain plug, but I have repaired a number of Zenith carburetors that had the drain plug stripped.

What I did was salvage a filter plug and unsolder the screen from it. The plug itself has a 5\8" hex, but is shaped like the drain plug with a dished out center, only it is larger.

I drilled out the stripped drain plug and tapped it with a bottoming tap to fit the threads of the filter plug. You have to be careful not to drill into the seat for the main jet.

The result is that instead of a 1\2" hex, you have a 5\8" hex.

Tom Endy

[SeaSlugs]

Well, how often does one need to drain the carb? JB weld does wonders... Might even be able to fill in the threads and retap them and MAYBE get some extra grip.

[jchochole]

Does JB Weld hold up against Ethanol?

[Jeff/Illinois]

Looks like the mounting flange is pretty warped. Common issue on these carbs.

Can be filed down no need to toss the carb out.

I stripped this same drain plug once on our '29 Tudor. Got too heavy handed on it. A friend that had antique cars carefully tapped it, put a slightly bigger brass plug in it, shellacked the whole thing and told me 'Never take this out again' and I never did.

That was 1974 and I'm still going strong with this same carb!

[SeaSlugs]

Originally Posted by jchochole

Does JB Weld hold up against Ethanol?

Yea, they make stuff specifically for sealing holes in gas tanks - kinda silly putty/modeling clay in consistency. Any auto parts store has a whole section of various goops and adhesives for repairing everything.

JB is currently sealing the tailshaft casting of the trans of my "modern" car and the drain plug (previous goober tightened the drain plug way too tight and cracked the housing) No leaks in 9 years 20-30K miles...

[jchochole]

Okay, gotcha- I didn't remember that stuff. I am sure that'll hold just fine.

Thanks,
Jim

[Jeff/Illinois]

Do they still make or sell 'gorilla snot?' Some guys used to use that don't recall the actual brand name.

[MikeK]

Originally Posted by jchochole

Does JB Weld hold up against Ethanol?

Absolutely Not! You may end up plugging the leak, but despite the package claims the epoxy itself will degrade and dissolve in E10. After it is washed out of the fuel contact surface you are left with only a plug of the ground silica and other fillers.

Why: There are at least five different epoxy chemistries. The bisphenol A, B, and Aliphatic blend types are cheap to produce but have poor resistance to alcohols. The JB gas tank sealer is based on bisphenol-A chemistry. You can see for yourself in their MSDS. LINK This stuff may hold up for a year or even two, but it no long term solution for an E10 fuel tank.

Epoxy/ filler blends based on Novolac chemistry are highly resistant to E10, but the uninformed auto parts store customer will not pay $12 for a fix when something else labeled 'gas tank repair' for $6 hangs on a pin next to the good stuff.

There are fuel tank sealers sold that are based on novolac catalyzed epoxy chem that would make an excellent tank hole patch if used with glass cloth but the smallest quantities available are 1 pint kits, about $45.

[dPokie]

What about a Heli coil. I had to do that on my tilly when I cross threaded the fuel inlet.

[Bill Cal.]

I had a friend with a metal lathe make me a new brass plug. He thought it was a fun little project. Works great!