Jets Corroded In About 7 Months From Ethanol Blended Fuel

[63 Sprint]

This is what ethanol fuel did to the primary jets on the Holley 390 carb in about 7 months.

I wanted to post this earlier, but, I wanted to make sure that I had the facts correct before posting.

It’s pitiful that we have to go through this.



These jets were nice and shiny when installed. If you look closely, it looks like the brass is corroded.

I never seen this happen on ethanol free fuel.

I’m stopping complete use of ethanol fuels in everything that is carbureted. This is downright ridiculous. Jets should last for years.

Just wanted to give everyone a heads up on what to expect when using ethanol fuels.

 

[PSIG]

They are fine, just discolored. The issue with ethanol blends is phase separation, which typically takes around 2 weeks if the car sits, and water separates-out and sinks. It's the separated water that encourages corrosion.

I'd suggest using an ethanol stabilizer. My son's imported scooter with carb recommends ethanol stabilizer in every fill-up right in the factory manual, for example. Most of us don't have issues with ethanol blends if operated regularly to either consume before phase separation or to "shake-up" the moisture and consume it. Using modern R9-rated fuel hose will substantially increase their lifespan. Carb float needles should be plain, NBR (Viton) or FKM/FPM (Buna-N).

Modern cars have fewer problems as they are somewhat more resistant with these materials, but also their EFI fuel systems stir-up the fuel on every run, so the water is mixed and consumed and it doesn't collect as much or in the same areas. Likewise, our carbs and fuel tanks are uncontrolled and directly vented, constantly 'breathing' with temperature changes, allowing the hygroscopic ethanol to collect more water vapor. Hope that helps.

 

[63 Sprint]

Looking closely under a friend’s microscope, the jets looked like they were etched and pitted slightly. The truck is started up every day and driven a half mile to the shop. It’s not used as much since I got the motorcycle in late July.

The fuel system is designed to constantly circulate fuel back to the fuel tank from the pressure regulator. The fuel line is about a foot long from the regulator to the carburetor. This also prevents vapor lock in extremely hot weather.

From what I understand and experienced. Today’s ethanol fuels in my area have a higher percentage than 10%. Newer fuel injected vehicles can tolerate higher ethanol content than carb’d engines.

You would think carburetor manufacturers would look into stainless jets in carburetors.

I read that in aluminum boat manufacturing, Stainless and aluminum would have a reduced rate of corrosion than aluminum and brass. And it’s highly recommended to use aluminum or stainless fasteners on aluminum hull boats.

I replaced too many carb’s on power equipment for others. I never had a problem since I never run ethanol based fuels in any of my carb’d equipment. Same carb’s for over 20 years. And they were never apart.

Ethanol is evil, and does horrible things to carb’s on power equipment. And I see that it looks like the same is true for carb’d vehicles. The corrosion just happens to effect small engines on power equipment much faster because jets an emulsion tube holes are much smaller than ones used in larger engines.

Fuel stabilizer does help, but it’s not the cure. I recommend it to some of my customers. But I still tell them to run their power equipment dry at the end of the season and drain the carburetor bowl if they’re able.

 

[Frank]

Ethanol is evil, and does horrible things to carb’s on power equipment.

C2-H5-OH . . does horrible things to people too.

 

[frozenrabbit]

Not practical for a car, but I've been separating ethanol from pump gas at home to run in my 2-stroke '78 Yamaha.

About a quart of water, with some food coloring added to 4 gallons of gas, mixed and let to set for 24 hours. Then I drain the water off the bottom. The ethanol attaches to the water. What I get out seems like more than 10-15%.

I let ethanol fuel sit in the carb over the winter a couple of years ago, 'bloom' corroded the whole inside of the aluminum float bowl, clogged jets and passages.

Here is a photo of the separation layer, there is a ton of garbage in our gas........ Water and contaminates on the bottom, ethanol free fuel on top. Contaminates are not from my set up, I get a layer that looks like this from every batch.

 

[63 Sprint]

C2-H5-OH . . does horrible things to people too.

But, C2-H5-OH sure helped bringing some beautiful babies into this world.

 

[PSIG]

You would think carburetor manufacturers would look into stainless jets in carburetors.

I asked about that some years ago, and the response was that SS jets would corrode the threads in the carb body through galvanic corrosion. Plus higher cost. They effectively opted to sacrifice jets than the body threads under those conditions. Makes sense.

 

[Bronctopia]

Monel would be maybe worth a try.
A CuproNickel alloy. Usually marine use, but they do make nice brake line tubing from it.

I asked about that some years ago, and the response was that SS jets would corrode the threads in the carb body through galvanic corrosion. Plus higher cost. They effectively opted to sacrifice jets than the body threads under those conditions. Makes sense.

 

[sixtseventwo4d]

I asked about that some years ago, and the response was that SS jets would corrode the threads in the carb body through galvanic corrosion. Plus higher cost. They effectively opted to sacrifice jets than the body threads under those conditions. Makes sense.

Very true in many instances, stainless and aluminum don't typically go well together. something, something_in-law effect.

You would think carburetor manufacturers would look into stainless jets in carburetors.

cost-prohibitive mostly. The cost to drill stainless on a manufacturing level would be greatly increased over that done in brass.

 

[63 Sprint]

Monel would be maybe worth a try.
A CuproNickel alloy. Usually marine use, but they do make nice brake line tubing from it.

Years ago, when I modified my transom on my 14 ft bass boat. Pressure treated plywood treated with copper solution was frowned upon. I seen pictures of aluminum transoms eaten through in a few years. G3 boats had a recall on some of their boats because the transoms were starting to leak. Many pictures were on line of the damage.
Today’s marine grade plywood can be purchased without copper solution.

I see that Monel has a high copper content.
The way it looks, it’s best to stay with brass jets and let them be the sacrificial anode to possibly protect the carburetor body and other components inside. It’s simpler and cheaper to replace jet’s every couple years than replacing a carburetor.

 

[wsa111]

I would like to see the flow test on the brass jets after several years of use?

 

[Bronctopia]

Years ago, when I modified my transom on my 14 ft bass boat. Pressure treated plywood treated with copper solution was frowned upon. I seen pictures of aluminum transoms eaten through in a few years. G3 boats had a recall on some of their boats because the transoms were starting to leak. Many pictures were on line of the damage.
Today’s marine grade plywood can be purchased without copper solution.

I see that Monel has a high copper content.
The way it looks, it’s best to stay with brass jets and let them be the sacrificial anode to possibly protect the carburetor body and other components inside. It’s simpler and cheaper to replace jet’s every couple years than replacing a carburetor.

Monel corrodes aluminum less than stainless 300 series.
Monel rivets were used on the original Aluminum Hobie catamaran spars and rigging for that reason. Now mostly those parts are composite.
The copper and chromium (and formerly arsenic) in treated wood are already oxidized, and in the form of cuprate and chromate SALTs. Which are far worse from a corrosion standpoint.