Author Topic: Weird crap in my carb...  (Read 553 times)

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Yellow Truck

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Weird crap in my carb...
« on: July 17, 2026, 06:13:45 PM »
The carb is a Quickfuel SS 830 on a 445. I haven't driven the truck much the last few years and this has happened twice. It clogs the idle circuits and the engine won't hold idle.

The stuff looks like a gel with a grit mixed in, after a couple of minutes the gas evaporates and what is left is a white powder with a bit of grit.

I'm running two fuel filters including a quick fuel 30-7007 100 micron. It is worth noting that we have been forced to start using fuel with ethanol - the Chevron 94 is now 7 to 8% ethanol. I rebuilt and cleaned the carb in an ultrasonic cleaner last fall and have not driven the truck more than 10 miles.

Any experience with this? It is kind of a drag to have to rebuild the carb when I want to drive it!
1969 F100 4WD (It ain't yellow anymore)
445 with BBM heads, Prison Break stroker kit, hydrualic roller cam, T&D rockers, Street Dominator Intake with QFT SS 830.

Paul.

TJ

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Re: Weird crap in my carb...
« Reply #1 on: July 17, 2026, 06:46:31 PM »
Everything I have with a carburetor gets an ounce per gallon of seafoam if it’s going to sit a few weeks for the reason in your picture.  Fuel injected gets the same if sitting for the winter.  Probably other stabilizers that work as well.

Yellow Truck

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Re: Weird crap in my carb...
« Reply #2 on: July 17, 2026, 07:30:01 PM »
Interesting - I have used Seafoam as a cleaning treatment, never considered it for stabilizing fuel. I have used Sta-bil for years, but one of my neighbours who has quite a collection told me to try Starbrite because it addressed the ethanol and prevented it from eating vulnerable rubber.

It was fuel with the Starbrite that went like this the first time, so I went back to Sta-bil and had the same result.
1969 F100 4WD (It ain't yellow anymore)
445 with BBM heads, Prison Break stroker kit, hydrualic roller cam, T&D rockers, Street Dominator Intake with QFT SS 830.

Paul.

TJ

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Re: Weird crap in my carb...
« Reply #3 on: July 18, 2026, 05:30:42 AM »
I’ve never investigated to see if seafoam stabilizes fuel or cleans out the crap that forms…might be a little of both.  Started using it over 15 years ago when I found bowls on my ‘65 and bowl on a riding mower full of jello after being stored all winter.  Now every carbed motor I have idles and revs nice after storage…push mowers, riding mowers, roto-tiller, 4wheeler, mini-generator, and the ‘65.

If you have a mess in the fuel tank, might take a bit to work that out.

allrightmike

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Re: Weird crap in my carb...
« Reply #4 on: July 18, 2026, 07:52:15 AM »
      Gasoline containing ethanol is like Kryptonite is to Superman in any vehicle not made for it at the factory. Here in Michigan ethanol free gasoline called "recreational gas" is generally available at 91 octane. I use it in everything I own with an internal combustion engine that wasn't made to use ethanol, including the lawn mower! You will never find that crap inside your carburetor with this fuel. I am aware ethanol free fuel is not available everywhere in the country and will not pretend to have an answer for that.
'60 Starliner 427 4speed.

1964Fastback

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Re: Weird crap in my carb...
« Reply #5 on: July 18, 2026, 07:57:58 AM »
I try to use non-ethanol in my Galaxie as well.  This site helps:

https://www.pure-gas.org/

Pat
1964 Galaxie 500 2 dr Fastback, 390, 4 speed, Indianapolis Indiana

Joe-JDC

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Re: Weird crap in my carb...
« Reply #6 on: July 18, 2026, 09:44:45 AM »
I put Stabil in one of my Mustang GTs gas tank because I knew it would be sitting for a couple of months.  When I went to start the car to move it, it would not start.  I opened the gas fill cap and the gas tube was rusted all the way to the tank.  The fuel was a gel, and the fuel pump had to be replaced.  Never again!  No Stabil for me.  Joe-JDC
Joe-JDC '70GT-500

hbstang

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Re: Weird crap in my carb...
« Reply #7 on: July 18, 2026, 10:41:32 AM »
same thing with stabil and pump gas,left a green slime in bottom of fuel tank.also was using some octane boost with the stabil but wont use it again.now i just drain front and rear bowls on carbs after i run them.pain in the ass for sure.

Yellow Truck

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Re: Weird crap in my carb...
« Reply #8 on: July 18, 2026, 02:51:21 PM »
I looked at the Seafoam website and they do recommend it as a fuel preservative just as TJ suggested. They don't mention if it is effective against ethanol contamination.

We used to get pure gasoline here in a few products, Chevron 94 was one. Government misguided environmental regs a year ago mandated ethanol in everything. I've got ethanol resistant fuel system parts in most locations, but I've been hearing from my fellow Canadian hot rod and antique car enthusiasts is the thing I'm seeing is water absorption and separation by the alcohol. This is made worse as I live by the sea in a fairly humid environment.

It turns to gel and settles in the bottom of the tank as well as in any place it can separate out of solution. I may have to drain my fuel tank as it accumulates.
1969 F100 4WD (It ain't yellow anymore)
445 with BBM heads, Prison Break stroker kit, hydrualic roller cam, T&D rockers, Street Dominator Intake with QFT SS 830.

Paul.

GerryP

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Re: Weird crap in my carb...
« Reply #9 on: July 19, 2026, 09:31:17 AM »
The active ingredient in Stabil is butylated hydroxytoluene (BHT).  BHT is a petrochemical preservative and is also used in the food industry as a preservative and by the health supplements markets as a dietary supplement.  You can buy crystalized BHT fairly cheap.  One teaspoon treats 10 gallons of gasoline.  Here's a site for it:  https://www.accessoryz.com/us/products/butylated-hydroxytoluene-c15h24o-99-usp-grade-crystals-6-oz-in-a-bottle-usa-90a9caf5e3d937cef8abf6c292128aa11bd80b89?v_id=variant_01KWPW86J2H99PA1N8M92VX1KH  You can find it on Amazon but you have to make sure you're looking at crystalized product, not capsules.  Here's a link:  https://www.amazon.com/Butylated-Hydroxytoluene-C15H24O-Crystals-Space-Saver/dp/B014H17CLW/ref=sr_1_4?crid=3OWHRCMV5ES1U&dib=eyJ2IjoiMSJ9.chM832AjHoWZUuXI8sBVvSvcxZRuUudd3uNWlAeWD51S6e5bOyVuN7lVh4P6L_r2QeSe2wUS-TiG-B_GBhiDo_Mlrpe2cu0WoNePtCpas_FmqNzu0EF7mZuPKBxGm3HoKxQEpbObjlLTDxLK0TwdackPZKbAUnwMeL1zi0K-L_LKR-ihC-8Kh5M9-EzrWeYG.KPehatPwYTFcWLOS-n7C_zoWucixECuWNC7GRFYa5VY&dib_tag=se&keywords=butylated+hydroxytoluene+crystals&qid=1784471235&sprefix=butylated+hydroxytoluene+crystals%2Caps%2C161&sr=8-4

chilly460

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Re: Weird crap in my carb...
« Reply #10 on: July 20, 2026, 09:54:50 AM »
I've had the same issues, and only marginally better with the available "stabilizers".  I try to run Ethanol free but the only place local to me has only 89oct.  There are YT videos where guys review the readily available stabilizers, all are a stopgap, but the ethanol free gas showed to be very stable. 

I'm not sure how you have your fuel pump setup or if it's electric, I set mine up with a manual switch so I can shut them off and run the fuel bowls dry before long storage.  This has seemed to help quite a bit. 

cjshaker

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Re: Weird crap in my carb...
« Reply #11 on: July 20, 2026, 04:43:52 PM »
I'm not sure how you have your fuel pump setup or if it's electric, I set mine up with a manual switch so I can shut them off and run the fuel bowls dry before long storage.  This has seemed to help quite a bit.

Absolutely the best way to do it....drain the fuel. I was a campus mechanic at a university and had over 120 pieces of gas and diesel equipment to deal with. Everything from weed eaters to fleet cars to tractors. Winter storage for the summer equipment got to be a headache come springtime when it was time to use them again (and vice versa), especially on small equipment that has extremely small orifices. I tried Stabil, Seafoam and a few others...and nothing worked good enough to stop the issues. It only stopped when I would drain all the summer stuff and make sure there wasn't any fuel left in them. It was a PITA, but saved me major headaches come spring. Since alot of small equipment has fuel shutoffs, that was easy to do on them; shut the fuel off and run until they died. Others had to be physically drained, then ran until they died. On a Holley with a mechanical pump, just remove a bottom bowl screw and drain each bowl.

The only stable fuel I've found is aviation or race gas. I mix it 50/50 in my Mach and I have yet to have a problem after sitting over the winter. It's a 110LL, so the lead probably helps in that matter. The several times I've removed a bowl for checking, they are always clean.
Doug Smith


'69 R-code Mach 1, 427 MR, 2x4, Jerico, 4.30 Locker
'70 F-350 390
'55 Ford Customline 2dr
'37 Ford Coupe

oldiron.fe

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Re: Weird crap in my carb...
« Reply #12 on: July 21, 2026, 02:15:06 PM »
   alcohol left in any fuel will be a problem after 3/4 weeks  I worked at a mil. esc (equip. storage site) with around 5000 pcs. of equip. also watch what alcohol cars do at a track to run -!!!                                 what works 1. to store/sit awhile  leave only alcohol free or min. amount alcohol added gas top off with non-alcohol-marine fuel-yes a few more bucks but better than junk in carbs. 2.I live in MN.                  and can have power losses and family/friends all have some back-up power-fuel does get stored for a time often longer time --again what works for standby power all installers around here use                  2.for standby power schaeffers neutra stabilizer/treatment only recomened stablizer in my area--schaeffers is a specialty manufact. co. stuff wrks--3. also add a correct amount of ashless oil it will keep anything from sticking I use marvel mystry oil --both available at any napa store  ---- unleaded fuel (no alcohol) starts to break down in 45/60 days--50/60s leaded fuel would start/run for                 years--- leaded race fuel will store in metal almost two years sealed well--not any unleaded pump gas today --no alcohol car leaves fuel in system for a time--stabil/schaeffers 2-cycle oil at any napa remember alcohol draws water to it (think heet for us in cold weather to keep fuel from iceing up) 
66' Fairlanes 427 (08/26/67- present)
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Stangman1

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Re: Weird crap in my carb...
« Reply #13 on: July 21, 2026, 10:50:25 PM »
With the ethanol in the fuel these days if you leave it sit for a while like over the winter it definetly will clog up orifices in carb. While I was doing motor a few years back got everything back together and could get it to run right. Took line off regulator and pumped it into a jug and it was like turpentine. That was only a year your saying 3 years that’s a lot. Doug’s right run the carbs dry if it’s gonna sit for 4 months or so.

RustyCrankshaft

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Re: Weird crap in my carb...
« Reply #14 on: July 21, 2026, 11:15:08 PM »
Running the carbs dry works well. I run non-ethanol gas as much as I can, but the last tank of the fall for sure. Don't run dry or any additives, just filled the tank, drive it home and walk away. But any ethanol gas is suspect, especially since a lot of states are under use waivers that allow considerably more than the % listed on the pump sticker.