[NeighborsComplaint]

My '71 GTO has never left me high and dry (hence to old faithful moniker) until today. Ran over to the grocery store with her and when I came out, she would fire but not start. It sounded flooded but holding the old foot on the floor did nothing. I'm a believer that it is always the simplest thing and I remembered I had secured the manual choke linkage open with a nylon zip-tie. I pulled the air cleaner lid and sure enough, the choke flap was shut but the zip tie was lying in the valley pan along with about 2" of gas. Ruh roh, a closed choke plate doesn't do that.

I snapped the choke flap back open (it locks open with a pretty positive detent) and cranked it for a moment watching the old faithful geysers of fuel coming out of the primary and secondary vent tubes. Yikes.

I got an Uber home and threw spare needles and seats, a spare carb, a sponge and some hand tools in a bag and Ubered back to the car. I swapped the needles and got the same result so I swapped carbs in the lot and sponge-mopped up the fuel. Twisted the key and it ran like a clock again, didn't even have to adjust curb idle as it was right were I'd left it.

The culprit? Both brass floats were full of fuel and weighted down. Car ran great with that carb when I put it away last fall and when I pulled it out of storage a couple days ago. Carb was dry over the winter and it probably just took a couple days of fuel in the float bowls to enter some pinholes in the solder and fill the floats to the point they couldn't function.

It's really odd that both brass floats would fail simultaneously but I'm blaming it on lead leaching due to high zinc content brass in the floats. The lead migrated into the copper and the soldered seam failed.

You guys with old (late 60's- early 70's) Holleys ever had this happen?

[turbo69bird]

Huh typically on holleys that’s a dirty needle and seat hung open. It is odd that both floats sank at the same time. Did you test these floats in a can of fuel? Just wondering how you’re sure it’s the floats filled .

[NeighborsComplaint]

Float is full of fuel. You can shake it and hear the fuel slosh inside. Sinks like stone.

[steve25]

I think the issue is how fast they make these brass floats.
Decades ago when they first started making them for a Q-jet I used one in a Carb I had rebuilt and just 5 months later it failed .
A seam just split open in a spot for a lenght of a bout 1/4".

The key to having these last when your repairing one is to preheat the float with a propane torch ( of course once all the fuel is out) and then solder up everything all while keeping the float hot with the torch.
After the soldering is complete back the torch away slow,y so the brass does not shrink fast and you will never have a problem again.

[OCMDGTO]

Good job getting back on the road!

[Formulas]

sounds most likely the floats secumbed to expansion and contraction breaking a seam due to temperature swings

less likely to happen to a black nitro floats

[mgarblik]

Had a somewhat similar situation happen a few weeks ago on my engine with 2 AFB's. Was on a 90 mile round trip and about 50 miles in the engine had just a slight rough idle and seemed to be loading up just a little at prolonged idle. Continued heading home and on the interstate I noticed if I backed out of the throttle, it felt like it was loading up and wanting to stall. I clutched it and dropped to 3rd gear and under load it was OK. Got to the I75-I70 interchange clutched it to slow down and it stalled. Rolled off into a safe area on the right and tried to restart, crank only. I had been heading home and was going to stop at a gas station to get some 0 alcohol fuel. Gauge said 1/8 to just under 1/4 tank. But you know how those old gauges are. Could not look in carbs because I had acorn nuts on air cleaners not wings. (for hood clearance). Had wife bring me 5 gallons of gas. Still no start. Let it sit about 1/2 hour to cool. Held the throttle about 1/2 open and did an extended crank and it started and ran super rough with black smoke, so I knew it was rich. Limped it home on surface streets keeping it under load and it ran rough but didn't stall. Once home and cooled off, I pulled the front carb airhorn. . One float was held mechanically way down and the other down some! Inspection revealed the seats had vibrated and unscrewed themselves. One was out almost 2 turns, the other about 3/4 turn. Floats were OK. Tightened the seats back in and it's been fine so far. Rear carb seats were snug. I tightened them slightly. So my advice is check the seats as well as the floats for leaks. First time I have been left stranded by one of my Pontiacs in 30+ years. Last time was an MSD that just died out of nowhere on the way to Norwalk Pontiac Nationals on I71 near Lexington, OH in the pouring down rain. Had to install my spare points distributor I carry in the trunk. Weird things do happen from time to time.

[Half-Inch Stud]

Good fixins! Hope you get fresh fuel in the GTO tank soon. Glad you had a spare known-carb.

Repaired a Brass mover float with Weller Gun to resolder, key to emptying the fuel was to let it pee out the leak hole awhile, then sealed the deal. Still good.

[61-63]

The best way to check floats is to fill a clear glass 3/4 full with water and put it in the microwave for 35 seconds, then stick the floats down in the water one after the other. If there is a leak in a float you will see bubbles instantly. No bubbles no leak.

[Greg Reid]

You just made me realize that it's a good idea to hold on to the identically set up second carb that I have on the shelf. Just have to make sure it's boxed or bagged. Pesky dirt daubers will plug up any hole they find.

[Skidmark]

Way to take care of business. No drama, just got her back up and running. Nice.

[RocktimusPryme]

That awesome, had to be a good feeling on the way home. Makes me regret selling my known good carb I had on the shelf.

The Firebird has been much the same but bit me once. Came out from work and it wouldn't start. And this was when I was working for the Dept of Defense so I was on a base. Would have been a nightmare to try and get a tow truck.

On a whim I decided to try it in neutral and it fired right up. Turns out that the little microswitch that served for neutral safety in my ratchet shifter had come loose and disengaged in Park. Got home and readjusted it with some triple duece for good measure.

[kingbuzzo]

glad it worked out...uber to the rescue

mental note: I really need that fire extinguisher

[NeighborsComplaint]

Thanks all!

After it initially tried to start and run, I walked around the back of the car and there was a 15' plume of wet gas on the floor from the passenger side tailpipe (assumed the high side of the dual plane caught the fuel and flooded the passenger side cylinders).

I had my extinguisher alongside the front wheel with the pin pulled at the ready the entire time.

[carbking]

All you guys talking about spare carbs, I just happen to know a source

Jon

[Cliff R]

The failure rate for brass floats here is 100 percent.

Yes, every single carb I sent out with one came back with the float sunk to the bottom of the bowl. Some only lasted a few days, some weeks and a couple over a year, but they still eventually filled up with fuel and sank. This prompted me to source out closed cell notrophyl floats and have had ZERO issues in over 20 years now.

This was back when we were rebuilding and restoring other types of carbs besides Q-jets, mostly 2JET and 4JET units. I've been cleaning up the shop in the past few months and found some of the brass floats from way back then and they are offshore production........

[geeteeohguy]

You ought to pull the dipstick and smell and check for gas in the oil. If there is, change it and the filter.

[NeighborsComplaint]

Originally Posted by geeteeohguy

You ought to pull the dipstick and smell and check for gas in the oil. If there is, change it and the filter.

Yeah, it was gassy so I drove it home watching the oil pressure the whole way. It was about 40 lbs as I was loping along just above idle so no harm done. Ran it over to the quick lube a couple blocks away the following morning.