Upper Cylinder Lubricant (UCL) mitigate corrosion?

Joined
Mar 15, 2026
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In addition to a fuel stabilizer (eg Stabil), does anyone think that also adding Lucas UCL or Amsoil UCL to the fuel could be beneficial to corrosion mitigation for infrequently run small engines? Probably overkill, but could it help?
 
Most small engines are aluminum bore. Some have liners. Would be more beneficial to just make sure both valves are closed if it sets for a while.

Throwing it under marginal cover and changing the oil every now and then will make it last longer than you care to use it so anything more is overkill.
 
I use Sta-bil for storage of my motorcycle and OPE engines. Mainly for the bike to prevent tank rust in the Winter storage. The OPE because I have it and dose the gas can before I fill it. The OPE have plastic tanks and finish them each season with non-ethanol fuel before I put them away for the winter. So probably overkill in one of two ways.
 
You may not need Stabil with the Lucas as I use it on my OPE too and I use it in my oil heating system etc.




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What I have found that seems to work good to keep out corrosion in the fuel system is to use the engineered 2-stroke fuel. The 2 stroke lube helps keep things a bit lubed and prevents bowl deposits and stuff. Has worked very well for a couple of small engines that have seen very infrequent use.
 
I have posted in detail before but YES a upper cylinder lube oil in the gas is a MUST for me!

Starting about 27 years ago I damaged a carb and petcock ( gas turn-off O-rings with racing gas ) on my then almost new 1997 Harley Heritage motorcycle, I call it dry gas for lack of a better word but my gas turn off ( petcock ) stuck, 1/2 way between on and off.

My old school Harley mechanic suggested dump that bad gas refill with normal gas and then if needed mix in some Marvel Mystery Oil ( It was still stuck so I added in some MMO with the gas, that gas turn off not only became unstuck but became slick like butter!That Marvel is the ONLY thing I have ever put in gas that I could actually "Feel" with my left hand every time a parked the bike at night when turning the bike off for the evening. The Petcock now had a slick feel when turning on and off much better than when it was new and before I used bad gas!

I became dependent on how that turn off felt and even years later ( I still have that 29 year old bike ) IF I don't add Marvel with my gas the turn off will not stick but it becomes less slick and smooth so that tells me that MMO lube MUST be great for rubber O-Rings in the carb too I assume? 27+ years now and no carb rebuild!

Well a few years after deciding Marvel would now go in most every tank of gas I had worry about winter storage so I reached out to Marvel and I reached out to Sta-bil and both told me should be no problem mixing both products.

So 27 years ago I started mixing both to the amounts the bottles suggest one use and I do this with each gas fill. ( always ethanol free gas ) and I fill it to the tip top of the tank and my three decade old bikes gas tank still looks shinny and new when I look with a flashlight! Filling to the top IMO is important for tank rust and I live at the beach with salt air.

But the funny thing is, my old Harley fely like it ran better, stronger, smoother with my mix of MMO and Sta-bil in every tank so thats what I did and now continue to do, EVERY tank gets my MMO, Sta-bil mix...

And then I buy a new Harley in 2023 and I think this is a modern bike so what do I do or not do with gas, storage etc?
My exhaust has no cat so can't hurt anything and I notice as soon as I add my MMO/ Sta-bil mix to my gas tank my fuel pumps volume is cut more than half, so IF Im traveling I may or may not be able to find ethanol free but I have a E00 93 octane pure gas pump close to the house so she gets the same treatment when in town, always no ethanol when in winter storage, mu my mix is in the tank on my new bike for local Sunday rides etc.


As far as lawn mowers 27+/- years ago it was simply easer to put ALL my small engines on my same Marvel/ Stabil / ethanol free mix so thats whats in my lawn mowers all the time and all are 25+ years old with no carb rebuilds.
The only thing I notice is the Red Marvel will turn the white on the spark plugs pink.

My cars and trucks with a cat don't get my gas mix but I own 3 Harley bikes and a old riding Snapper mower and Honda engine powered old push mower and my mix goes in every tank!
 
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I have posted in detail before but YES a upper cylinder lube oil in the gas is a MUST for me!

Starting about 27 years ago I damaged a carb and petcock ( gas turn-off O-rings with racing gas ) on my then almost new 1997 Harley Heritage motorcycle, I call it dry gas for lack of a better word but my gas turn off ( petcock ) stuck, 1/2 way between on and off.

My old school Harley mechanic suggested dump that bad gas refill with normal gas and then if needed mix in some Marvel Mystery Oil ( It was still stuck so I added in some MMO with the gas, that gas turn off not only became unstuck but became slick like butter!That Marvel is the ONLY thing I have ever put in gas that I could actually "Feel" with my left hand every time a parked the bike at night when turning the bike off for the evening. The Petcock now had a slick feel when turning on and off much better than when it was new and before I used bad gas!

I became dependent on how that turn off felt and even years later ( I still have that 29 year old bike ) IF I don't add Marvel with my gas the turn off will not stick but it becomes less slick and smooth so that tells me that MMO lube MUST be great for rubber O-Rings in the carb too I assume? 27+ years now and no carb rebuild!

Well a few years after deciding Marvel would now go in most every tank of gas I had worry about winter storage so I reached out to Marvel and I reached out to Sta-bil and both told me should be no problem mixing both products.

So 27 years ago I started mixing both to the amounts the bottles suggest one use and I do this with each gas fill. ( always ethanol free gas ) and I fill it to the tip top of the tank and my three decade old bikes gas tank still looks shinny and new when I look with a flashlight! Filling to the top IMO is important for tank rust and I live at the beach with salt air.

But the funny thing is, my old Harley fely like it ran better, stronger, smoother with my mix of MMO and Sta-bil in every tank so thats what I did and now continue to do, EVERY tank gets my MMO, Sta-bil mix...

And then I buy a new Harley in 2023 and I think this is a modern bike so what do I do or not do with gas, storage etc?
My exhaust has no cat so can't hurt anything and I notice as soon as I add my MMO/ Sta-bil mix to my gas tank my fuel pumps volume is cut more than half, so IF Im traveling I may or may not be able to find ethanol free but I have a E00 93 octane pure gas pump close to the house so she gets the same treatment when in town, always no ethanol when in winter storage, mu my mix is in the tank on my new bike for local Sunday rides etc.


As far as lawn mowers 27+/- years ago it was simply easer to put ALL my small engines on my same Marvel/ Stabil / ethanol free mix so thats whats in my lawn mowers all the time and all are 25+ years old with no carb rebuilds.
The only thing I notice is the Red Marvel will turn the white on the spark plugs pink.

My cars and trucks with a cat don't get my gas mix but I own 3 Harley bikes and a old riding Snapper mower and Honda engine powered old push mower and my mix goes in every tank!
I have customers ask me what is the best way to store their fueled equipment. I reply by asking what they are doing now. Invariably, I hear a litany of elixers and procedures. My second question to them is "are you having problems?" Usually the ones who ask are not having issues so I tell them to not mess with success and to carry on. It's the customers who come in with stink fuel from the last century and/or half a tank of water who get the E0 lecture. I've just brought in some Kinetix full synthetic FD rated two stroke oil with a fuel stabilizer included that should help. I'm going to try it in my equipment first before recommending it to anyone.
 
I live in an EPA nonattainment area, and we've had RFG since the 1990s. My lawn mower is 34 years old, my garden tractor is 26 as is the snow thrower, I have a 30 year old car and one that's 26 and I've never used a stabilizer nor a UCL in any of them. I do not always empty our the seasonal gasoline in my OPE and yet everything is running fine. What is different here that I don't see all these terrible problems I'm supposed to see with E10?
 
I have customers ask me what is the best way to store their fueled equipment. I reply by asking what they are doing now. Invariably, I hear a litany of elixers and procedures. My second question to them is "are you having problems?" Usually the ones who ask are not having issues so I tell them to not mess with success and to carry on. It's the customers who come in with stink fuel from the last century and/or half a tank of water who get the E0 lecture. I've just brought in some Kinetix full synthetic FD rated two stroke oil with a fuel stabilizer included that should help. I'm going to try it in my equipment first before recommending it to anyone.
I have a buddy who purchased a Vulcan around the same time I purchased my Harley ( 1997 ish ) his tank rusted out years ago, my tank looks new. My buddy tires were flat and sold his bike for junk on Craigslist when he sold his house and had to move the bike. This was after I moved away or heck if I had seen his bike begging for help and in need of rescue I would have helped without being asked... I assume he just parked it one day with a almost empty tank and things got so bad he didn't ride it again. He is the kinda guy who would have no idea what Sta-bil is and once the bike got too bad to drive to a dealer to be fixed he was sol.

My guess is if a bike owner is even somewhat aware that time, moisture, air, ethanol, a empty tank, old gas could be a problem, 1/2 the battle is won.

As someone who goes to great lengths to store gas and prevent damage some may say I overkill but sometimes I do wonder whats the minimum one needs to do? or what actually is the risk of say a 1/4 full Harley tank over the winter and how long could ethanol sit in a Harley metal tank without an issue?

I have a friend who is a boat mechanic and he a few years back told me horror ethanol stories but I don't her much about ethanol storage damage anymore? Is everyone treating ? using E00? wonder?

Even someone like me thats obsessive with my Harley gas storage can be caught off guard, one example mom health unexpected took a turn and then as time passed she could never drive again but her car sat with ethanol in the tank 2 years but it fired right up and is now back on the road with no issues.

My buddy lost his gas tank then his bike from sitting, moms car was fine ... What does one do?
 
I use MMO in fuel only for all of our vehicles with metal fuel tanks as well as OPE.

Many years ago, when I had an MG the local sage British car guru recommended MMO to protect the tank ullage area from corrosion. He felt that a healthy but safe dose of MMO leaves an oilier more protective film that fuel alone. MG's and Tr's are very susceptible to tank corrosion at the 'water line' for some reason and I have not had a problem with any cars that did not have it before I got them, so I stick with what works.
 
I live in an EPA nonattainment area, and we've had RFG since the 1990s. My lawn mower is 34 years old, my garden tractor is 26 as is the snow thrower, I have a 30 year old car and one that's 26 and I've never used a stabilizer nor a UCL in any of them. I do not always empty our the seasonal gasoline in my OPE and yet everything is running fine. What is different here that I don't see all these terrible problems I'm supposed to see with E10?
Categorize me as envious:
f carb deposit 17.webp
 
I live in an EPA nonattainment area, and we've had RFG since the 1990s. My lawn mower is 34 years old, my garden tractor is 26 as is the snow thrower, I have a 30 year old car and one that's 26 and I've never used a stabilizer nor a UCL in any of them. I do not always empty our the seasonal gasoline in my OPE and yet everything is running fine. What is different here that I don't see all these terrible problems I'm supposed to see with E10?
I've always believed the way and length of time that the fuel is stored is the key.
Ethanol isn't a problem until it absorbs water. Am I right?
 
I keep 15-20 gallons on hand. E-0. I swap it out every 6 months and burn it in the cars.
I keep my generator tank full to the brim to keep moisture laden air out of the tank.
I do use tcw3 as a winter additive in my mowers.

I use e-10 in my zero turn, but e-0 for the last few mows of the season and winter storage.
 
I use marine Stabil 360 and TCW-3 2-cycle oil.

Mix in the Stabil as directed on the label.
Mix in the TCW-3 2-cycle oil at a rate of 1oz to 5 gallons of gas.

I put both in the 5 gal gas container, then fill it at the local pump with regular 87. I haven't had an issue with the E-10 fuel in my lawn mower nor generators. I also use this mix to winterize my boat and motorcycle.

The TCW-3 oil (intended for marine use) has corrosion inhibitors and also leaves a thin film of oil after draining the tank and running the carb dry. It's also rather inexpensive and readily available. I used up some old Poulan and Stil 2-cycle weed whipper oil in this manner as well. It seemed to work fine.
 
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