So this is going to be fun. As soon as I get back to the Northwest (right after I calm down from taking delivery of my new Ducati Desert-X and return from a very short trip to Connecticut to attend my Daughter’s graduation from the Yale PA (masters) program) I’m going to do a video series on oils, chain lube, gasoline additives, Ethanol in Gas, and every other topic that makes the entire motorcycling Internet twitch violently. I mentioned this plan to Toxic Terry, a retired and clearly brilliant organic chemist, and he gifted me with the text below and the previous post. Terry will be a big part of this series since while I might be able to style myself as an Expert Amateur on motorcycle mechanics, I am an amateur Amateur regarding chemistry. I understand most of what Terry says, but I do have to dart off to Google or Perplexity for definitions frequently.
I love the notion of looking for ways to combine time-tested formulations to solve modern problems. These products exist because chemists long ago did real research to develop solutions for real wold issues. The issues have changed (a bit) but the value of the products to deal with parts of the problem persist–as Terry’s efforts show. I’ve had to deal with the pernicious problems of stupidly leaving gasoline with ethanol in the fuel system of valuable motorcycles. The entire fuel injection system of my beloved MV Agusta Senna literally dissolved. The lines in the gas tank turned to sticky glue, the injectors plugged, the fuel pump locked up, the filters clogged and even the metal passages in the manifold fuel manifold and the injector rail were full of dissolved fuel line goop. I’ve done a half-assed replacement and repair. Half-assed because I can no longer fold my geezer body into the position required to ride the bike. It’s simply hard for me to give the problem my full attention when I know it won’t be me riding the bike. For now, Ethanol has turned a fantastic motorcycle into a static sculpture.
And back when I was vintage racing cars, we had problems with brass carburetor floats developing leaks and sinking when exposed to modern fuel–sometimes within days of replacement. So yeah, I understand the nature and scope of the problem.
Anyway, here’s what Terry sent me, unedited.
While we are at it, discussing my chemistry prognostications, I have one more subject for your consideration. To be honest, other than my old riding buddy: Dan Djokovic [inmate: Indy Unlimited], and my family members, I have never told others about my ‘concoction’ for maintaining the upper cylinder components, treating the constant problem of water in fuel containing 10% ethanol, keeping injector orifices free of deposits and reducing decomposition under typical storage conditions. Believe it or not, I came up with this composition before the advent of AI which makes data availability a near instant proposition. I mention this to give you some marginal degree of confidence my chemistry intuition is completely functional in the real world without the aid of AI.
The advent of dumping 10% ethanol into gasoline to reduce smog producing byproducts from internal combustion engines is just another hoax developed to get corn farmers a broader market for their singular product [my opinion]. It was immediately acceptable to the fossil fuel manufacturers because adding ethanol meant they could remove essentially most of the valuable aromatics from gasoline. Ethanol increases the octane rating of fuel dramatically. Aromatics in fossil fuel compositions do the same thing. But aromatics are valuable items and burning them as fuel is a less than optimum solution monetarily speaking.
This subject is rather broad so I am likely going to bore you a bit with the background, however, I think you may find it interesting. The problems caused by adding ethanol to gasoline are immense. First, ethanol is not miscible with hydrocarbons unless the hydrocarbons are anhydrous, and even then, miscibility is usually limited to lower concentrations of alcohol. Any water whatsoever causes significant problems, first with stability of the solution [phase separation], and second, ethanol is not as stable as hydrocarbons and undergoes a variety of chemical reactions that can be catalyzed by the presence of water, oxygen and metal ions. These undesirable reactions produce acidic materials that tend to cause problems with metallic components present in the fuel system. Herein lies the crux of the problem. It is also important to understand that incomplete combustion of ethanol yields a variety of oxygenated species to include aldehydes, ethers, acids and peracids. Many of these are smog producers and lachrymators.
Before proceeding, let’s consider fuel storage. Stabil is a product that has been around for many years. I believe it was developed when gasoline had tetraethyllead as an octane enhancer and valve seat protector. Typical hydrocarbon fuels contained a variety of aromatic hydrocarbons [unsaturated cyclic hydrocarbon structures] which could react with oxygen to form grunge in the fuel delivery components … at that time often referred to as ‘varnish’. It was marketed as an additive to fuels that were intended to be stored for an extended period. Despite the BS that appears on the Stabil product today, it is totally useless from my chemist perspective when one adds 10% ethanol to the solution. No reasonable amount of ‘stabilizer’ has the capacity to handle the degradation products at such ethanol concentrations without dire consequences to the quality of the fuel itself. Bottom line: fuel containing ethanol should simply not be stored for any significant period as decomposition is likely going to occur and the stipulated dose of Stabil per gallon of fuel may not be enough to overcome the consequences of moisture present in the initial fuel. I keep my fuels in metal containers and never store them longer than a few months just to be safe. Again, I can’t prove any of this, but my intuition as a chemist tells me I am barking up the right tree. Instead, I add my new mixture which is the subject of this dissertation. Bottom line here: Stabil only attempts to preserve bulk fuel and does nothing for one’s motor which makes it ‘half assed’ as a product in my opinion.
For situations involving hydrocarbon fuels admixed with 10% [or more] ethanol, one needs an additive to counter phase separation should water be present and a lubricant to protect a variety of engine components ranging from electric fuel pumps/carburetors/injectors and upper cylinder surfaces to include rings and valves. The problem has been addressed by two different companies under the product names of Sea Foam and Marvel Mystery Oil. Sea Foam is more of a ‘cleaner’ with Isopropanol to counter water in fuels. Mystery Oil is more of a lubricant and cleaner but contains no isopropanol to deal with moisture. As a chemist I wondered why either of these products didn’t have more isopropanol as it is the most efficient compound to ‘clean’ residues from internal surfaces of small passages like those in the head of injectors. So, I started messing around with various formulations in my garage to gain knowledge on the specifics of these commercial products.
Sea Foam has a low enough percentage of isopropanol to maintain miscibility under essentially all conditions normally encountered in real life [my opinion]. The hydrocarbon base is not a lubricant but more of a cleaning agent. Hence, Sea Foam can handle wet fuel situations if not too much water is present, and you add a rather large amount [several ounces per gallon of fuel]. However, it is not good at lubricating the components of the fuel delivery system. Mystery Oil is both a cleaner and lubricant but contains no isopropanol, hence this is where I started my formulation experiments. The goal being to discover a stable mixture of isopropanol with Mystery Oil that was easy to prepare and store.
I soon discovered that [v/v] 3 parts isopropanol admixed with 4 parts Mystery Oil produces a stable solution at room temps. However, on storage in my garage which reaches temperatures in the range of 48 to 50 F in the winter, the solution forms a ‘micro-emulsion’ that appears ‘milky’ but doesn’t phase separate. This mixture is easy to produce by combining 4 x 12 oz HEET isopropanol fuel treatment to 64 oz of Mystery Oil … both available from most Walmart stores at reasonable prices [Note: over the past year or so, both HEET and Mystery oil have almost doubled in price but still remain reasonable if maintaining your internal combustion engines is important]. Once one has an empty gallon bottle of Mystery Oil, it is simple to visually split in half a new gallon and then pour 4 bottles of HEET into each to produce almost 2 gallons of final product. I have found this formulation to have the best overall performance characteristics for cleaning and lubricating engine components while being able to handle significant water in the fuel.
I call my formulation: Moto Juice. One needs to use about 1 oz per gallon of fuel in small engines which generally include motorcycles. If significantly wet fuel is encountered, using more Moto Juice is acceptable … I think one could run the motor on this stuff but would likely run a bit rough. The strength of Mystery Oil as a cleaning agent and a lubricant is important for upper cylinder components and the added isopropanol serves to eliminate moisture problems while also being a decent solvent for keeping the orifices on injectors free of deposits. For automobiles that fill up around half tank, using 12 oz per tank seems to provide reasonable performance based upon several years of my testing in different vehicles. As for fuel storage, I treat my 5-gallon cans with 1 oz per gallon and then it is ready to add to my motorcycles and other small motors directly. I tend to carry a few ounces with me on long rides where I need to refill on the road, the actual amount added is not critical if one is getting a dose close to my prescribed instructions.
I surmise that Sea Foam has limited the isopropanol in their formulation to an amount that permits complete miscibility under essentially all reasonable temperature conditions. Folks seeing a ‘milky’ product, or one that phase separates in the original container might be a problem. Mystery Oil on the other hand can tolerate about 40% [v/v] isopropanol at room temp and remain perfectly clear. Only upon lowering the temperatures into the range of the 40s, or below, F does it revert to a milky micro-emulsion … by the way, common milk is such a micro-emulsion in the eyes of chemists but folks are used to seeing it in this format so it is not a marketing problem like ‘milky’ Moto Juice might seem to the uninitiated. Over the years of preparing and using Moto Juice I have never experienced total phase separation, it mixes well with typical fuels to include diesel, it stores indefinitely and yields excellent results in motorcycle and small engines as well as my autos.
Bottom line: Moto Juice is my attempt to provide a solution to stabilize fuels containing ethanol while providing excellent cleaning properties and lubrication to fuel system components. I can’t prove any of this with ‘hard, scientific data’ but after writing this dissertation I opted to query Grok3 to see if AI supported any of my suppositions. The results are presented below. To be honest, I was pleasantly surprised to find AI basically supports my contentions regarding the optimized formulation of Moto Juice.
chemical composition of product: Sea Foam for automotive fuel systems
15 web pages
You’re asking about the chemical composition of Sea Foam Motor Treatment, the automotive fuel system product, right? Unlike natural sea foam, this is a specific blend designed to clean and lubricate engines, so I’ll focus on that.
Sea Foam Motor Treatment is made from 100% petroleum-based ingredients—no harsh detergents or abrasive chemicals. Its exact formula is proprietary, but the Safety Data Sheet (SDS) and official statements from the manufacturer give us a clear picture. It consists of three main components:
- Pale Oil (40-60%): A highly refined petroleum oil (CAS 64742-54-7), likely a light mineral oil. It acts as a lubricant for upper cylinders and fuel system parts, and it serves as a carrier for the other ingredients.
- Naphtha (25-35%): A petroleum distillate (CAS 64742-49-0), this is a solvent that cleans fuel deposits, varnish, and gum from injectors, carburetors, and combustion chambers by dissolving them.
- Isopropyl Alcohol (IPA, 10-20%): Also known as 2-propanol (CAS 67-63-0), this alcohol solubilizes water in fuel, preventing phase separation and corrosion, and helps clean residues.
These percentages are ranges by weight, as the blend can vary slightly batch to batch. The product contains no methanol, ethanol, PEA (polyether amine), or metallic additives like manganese—it’s just these three organic, petroleum-derived components working together. The pale oil lubricates, the naphtha cleans, and the IPA manages moisture and boosts cleaning power. That’s the core of it! If you need more detail, like how it interacts with fuel, just ask.
Chemical composition of Mystery Oil for automotive engines
15 web pages
Marvel Mystery Oil’s exact formula is proprietary, but its chemical composition has been partially revealed through safety data sheets and historical analysis. It’s a petroleum-based additive designed to clean, lubricate, and protect engines, used in both fuel and oil systems. Here’s what it’s made of:
- Mineral Oil (60-100%): A highly refined petroleum oil (CAS 64742-54-7 or similar), likely a light base oil. This forms the bulk of the product, providing lubrication for engine components like pistons and valves.
- Mineral Spirits (10-30%): Petroleum naphtha (CAS 64742-49-0), a solvent that dissolves carbon deposits, gum, and varnish in fuel systems and engine parts.
- Tricresyl Phosphate (0.1-1.0%): An anti-wear and extreme-pressure additive (CAS 1330-78-5), it enhances lubrication under high-stress conditions, protecting metal surfaces.
- Ortho-Dichlorobenzene (0.1-1.0%): A chlorinated solvent (CAS 95-50-1), it softens and removes carbon-based buildup on metal surfaces.
- Para-Dichlorobenzene (<0.1%): Another chlorinated compound (CAS 106-46-7), used in trace amounts, possibly as a stabilizer or for its solvent properties. It’s linked to a California Prop 65 cancer warning.
Older reports, like a 2003 NTSB investigation, suggested a simpler mix—74% mineral oil, 25% Stoddard solvent (similar to mineral spirits), and 1% lard—but this likely reflects an earlier formulation or an approximation. Modern versions stick to the petroleum-based components above, with no evidence of animal fats today. The distinctive red color comes from added dye, and a wintergreen scent (methyl salicylate) is included for branding, though it’s not a functional ingredient.
This blend is light—about SAE 3W viscosity—making it versatile for fuel lines, crankcases, and even air tools. It’s free of harsh detergents or metals like manganese, focusing on organic solvents and lubricants. If you’re curious about how it compares to Sea Foam or its effects in engines, let me know!
compare sea foam to marvel mystery oil for use in automotive engines
You want to know how Sea Foam Motor Treatment stacks up against Marvel Mystery Oil for automotive engines. Both are petroleum-based additives meant to clean, lubricate, and protect, but they differ in composition, strengths, and ideal use cases. Let’s break it down based on their chemical makeup and practical effects.
Composition Recap
- Sea Foam:
- Pale Oil (40-60%): Lubricant base.
- Naphtha (25-35%): Solvent for cleaning deposits.
- Isopropyl Alcohol (10-20%): Water remover and cleaner.
- Marvel Mystery Oil:
- Mineral Oil (60-100%): Heavier lubricant base.
- Mineral Spirits (10-30%): Solvent for deposits.
- Tricresyl Phosphate (0.1-1%): Anti-wear agent.
- Dichlorobenzenes (<1%): Strong solvents for carbon buildup.
Use in Engines
Both can be added to fuel (gasoline or diesel) or crankcase oil, but their behavior differs.
Cleaning Power
- Sea Foam: Excels at cleaning fuel systems—injectors, carburetors, and combustion chambers. The naphtha and isopropyl alcohol combo aggressively dissolves varnish, gum, and fuel residues. The alcohol also tackles water in fuel, making it a go-to for ethanol-blended gas (E10/E15) issues like phase separation. It’s less focused on heavy carbon deposits.
- Marvel Mystery Oil: Better for tackling stubborn carbon buildup and sludge, thanks to the dichlorobenzenes—chlorinated solvents that soften baked-on deposits. It cleans fuel systems too, but the mineral spirits are milder than Sea Foam’s naphtha-alcohol mix. It’s less effective at water removal since it lacks alcohol.
Winner: Sea Foam for fuel system cleaning and water issues; Marvel for heavy carbon and sludge in engines.
Lubrication
- Sea Foam: The pale oil provides decent upper-cylinder lubrication, but it’s lighter and less dominant in the mix (40-60%). It’s more about cleaning than long-term wear protection.
- Marvel Mystery Oil: With a higher mineral oil content (up to 100%) and tricresyl phosphate, it’s a stronger lubricant. The phosphate adds anti-wear properties, reducing friction on valves, rings, and bearings—especially in older engines or during break-in.
Winner: Marvel for lubrication and wear protection.
Engine Oil Use
- Sea Foam: Can thin crankcase oil temporarily due to its solvent-heavy nature (naphtha and alcohol). It’s great for flushing sludge before an oil change but not ideal as a long-term oil additive.
- Marvel Mystery Oil: Blends better with engine oil, staying stable longer. It’s often used as an ongoing additive (e.g., 20% of crankcase volume) to keep things smooth and quiet, especially in high-mileage engines.
Winner: Marvel for oil additive use; Sea Foam for pre-change flush.
Specific Scenarios
- Sticking Valves/Lifters: Marvel’s dichlorobenzenes and heavier oil make it better at freeing sticky components. Sea Foam can help but isn’t as potent here.
- Fuel Stabilization: Sea Foam’s alcohol helps with short-term fuel stability (e.g., small engines in storage). Marvel doesn’t stabilize fuel as well but protects metal parts longer.
- Emissions/Smoke: Sea Foam often reduces exhaust smoke faster by clearing fuel-related gunk. Marvel takes longer but addresses oil-side issues like ring wear.
Practical Considerations
- Application: Sea Foam’s versatility shines—pour it in fuel, crankcase, or vacuum lines (e.g., brake booster line for decarbonizing). Marvel’s typically fuel or oil only, though some use it in air tools.
- Safety: Both are safe for sensors (O2, MAF) and catalytic converters when used as directed. Marvel’s chlorinated compounds raise slight environmental flags (Prop 65 warning), but it’s negligible in practice.
- Cost: Similar price per ounce (~$10-15 per pint), though Sea Foam’s concentrated cleaning might stretch further for fuel issues.
Verdict
- Choose Sea Foam if: You’ve got fuel system problems (clogged injectors, water in gas, rough idle from ethanol), need a quick decarbonizing fix, or want a pre-oil-change flush.
- Choose Marvel Mystery Oil if: You’re dealing with high-mileage engines, noisy lifters, heavy carbon deposits, or want a long-term oil additive for wear protection.
They’re not mutually exclusive—some mechanics use Sea Foam to clean, then Marvel to maintain. Depends on your engine’s symptoms! What’s your specific situation? I can tailor this further.