MTFCA Forum

Good evenings my Model T brothers, I hope this all finds you well.

My carburetor gas leak has returned, probably right at where the right turn valve is threaded into the carburetor. It drips onto the flat cap of the bowl. See picture. I don't know what to do about this, I suspect the threads are loose on the carburetor. I am open to suggestions.

I noticed when I ran it to church today and kept it running to check the carburetor that the front spark plug has oil bubbling up around it see picture. I think I have been running it with this for years. It seems to run ok. I checked the obvious that the plug is tight and it is. Should I be concerned?

Thank you for the help and wisdom.

Be sure your oil level is not too high. Some plugs seal better than others, and after 100 years, some threads are worn in cylinder heads. If the front cylinder misses intermittently, it may accumulate excess oil that would otherwise be burned off.

The spark plug threads can be sealed with Teflon tape or with some other method such as pipe thread dope. Some even use aluminum foil as a sealant.
I I used to think more oil is better. That was a mistake. The number 1 and/or 2 spark plug would get very oily and I wonder why. It was caused by excessively high oil level in the crankcase.

Art Mirtes

The bubbling is a common thing. Caused by malformed threads on the spark plug. Do as Art suggests to seal it. Otherwise, it's not a big deal. Just messy.

I have been successful with aluminum foil around the spark plug threads. I agree that oil too high could cause excessive oil in front especially if you go downhill. The oil can run to the front, however when you go uphill it tends to run toward the back, so you need to keep no higher than the top petcock, and if oil runs out the bottom petcock don't add oil. Be sure however the petcocks are not clogged up. If you open a petcock and no oil runs out, insert a wire with the petcock open. If oil runs out then it was clogged and you don't need to add any oil.
With the carburetor, it is a bit harder to fix, because sometimes the elbow is not tight when it is in the right position, but one more turn might crack the casting of the carburetor and ruin it. So you need some type of sealer which is not affected by gasoline or alcohol. They do make a teflon tape for that purpose. Just be careful to use an amount which will not actually go past the threads on the elbow so that it doesn't interfere with the operation of the needle valve.
Good luck. Glad the weather is letting you drive the T.
Norm

Anti-sieze on the spark plug threads will stop the oil bubbles. The plugs will also come out easier next time you need to remove them too. Same thing used on aircraft engine plugs.

Hummm....for the 50 years we have had the 1922 Ford, it had bubbled and leaked. And now at 100 years after manufacture, it still bubbles and leaks.

My car bubbled at the front plug and would smoke if idled for more than a short time. It has a high flow Texas T auxilliary oiler on it. I reduced the flow rate of the oiler and it no longer smokes or bubbles any oil. I keep the oil level halfway between the upper and lower cock. I use 5W30 or 10W30 full synthetic oil. No water pump.

If your car runs well on all cylinders and does not use excess oil or blow oil out the oil filler cap, it's probably OK. Spark plugs should not foul.

Can we really say that in the Model T era and into the late 1930’s that there were Model T’s being driven daily that didn’t leak gas, oil, or grease? I’m not poking fun at this thread but I guess we want our T’s to good as can be. I know I do!
The slow drip or leak around the carburetor elbow usually can be stopped with gas specific Teflon tape that has been mentioned and hopefully the carburetor elbow inlet area hasn’t been cracked from years of over tightening. It can happen pretty easy when trying to get the elbow to tighten just one more round to try to stop a leak.

After 50 years plus ownership, the bubbles and leaks must be caused by the water pump.

When members of the public ignore the Experts and combine water pumps with Marvel Mystery Oil, waterless coolant, and teflon tape, the result is an existiential threat to every living thing on this planet!

I have had good luck with permatex #2 on pipe threads. Pretty much use it on all threaded pipe. It is does have a near magic ability to get on your hands, tools and everywhere else but can be cleaned up with rubbing alcohol (not much else will remove it). Been around about as long as Model T's. Never liked the look of teflon tape.

Permatex would probably work on T spark plugs to although it wouldn't be the first choice. Never-seize is great as well have been able to remove nuts on exhaust manifolds and such when the nuts have rusted down to the next smaller size (winter salt is tough on cars in the heart of the rust belt - Michigan). Have used never-seize on VW spark plugs many years yet to strip out a plug very common with their aluminum heads.

Gee Wizz Pat, ..... Who are the Experts. ??? I thought we post here in the forum to ask for owners experience and help that we use to fix our cars ourselves. ..... And a little comedy along the way doesn't hurt.

It is not for us to question the Experts, let alone question who they are....

Aviation Fuel Lube on the carb fitting will stop the leak.

Aviation Fuel Lube is great stuff BUT won't fix any cracked inlet which is easy to do as referenced above ! That type of accessory shut-off isn't known for reliability in the "no -leak" dept.

Permatex #2 is worth a try. I've found that aviation lube (I have a lifetime supply with the tube I have) in my experience doesn't hold up for long with gasoline.

I use Gasoila on fuel line fittings (they also make a version for ethanol blended fuels) and spray copper coat (for head gaskets) on the spark plug threads.

BUSHMIKE wrote: ↑

Mon Feb 27, 2023 7:11 pm

Aviation Fuel Lube on the carb fitting will stop the leak.

Good idea, I have used it for years.

Hi Ignacio,
Finding leaks is a pain. One solution I have found for locating leaks is to clean & dry the carb with brake clean or carb clean. Spray the
carb with aerosol foot powder. This will cover the carb with a soft white coating. Turn on the gas the leak should show up as it soaks up
the powder. GASOILA red is a hardening thread sealant that does not have a lot of lubricating quality that can promote over torqueing
that can crack the carb body.
One probably unpopular solution to spark plug leakage is to install modern plug adapters with some kind of sealant like Loctite 660 so the
leak is stopped and plug sealing is done with the plug gasket. There is a plethora of objections to this, one being they don't look original.
For that I take a handful of discarded model T plugs ( I prefer the later crimp style ) Machine off the crimp, bore the body out big enough
for the modern plug, drill & tap for the 14mm plugs. Install with Loctite 660 in the head. You have a adapter that looks just like a 1/2"
plug. Just install your favorite long reach 14mm plug.
Craig.

Alright! The Gasoila fixed the fuel leak problem and the Permatex fixed the up through the ground came a bubbling crude problem! Now when I go to church there isn't a puddle of gasoline under the car when I come out. You can just see a bit of Gasoila excess on the fuel line and the carburetor in the picture. Thanks to all for the suggestions.