It's strange how often I hear about this. I'll share my experience for what it's worth. In all my years (I'll be 65 in a couple months) I can only remember one time when I had gasoline go bad and even then it didn't require any repair.
One fall just before winter I pulled out my gasoline powered ice auger and attempted to fire it up as I always do. It wouldn't start, which was unusual. I opened the fuel tank to check for gas and found that it smelled like diesel fuel. I poured it out into a metal tray and tried to light it with a match. It would not burn. I discarded it and poured new mixed fuel into the tank on the auger, pressed the primer button about 5 times and it started in two pulls and ran just fine. About 5 years ago I decided to add Stabil fuel stabilizer every spring before storing it. No particular reason but It's become a habit.
As far as other gasoline powered machines that I use I use 87 octane with 10% ethanol in all of these. Of all of these I only use fuel stabilizers in the ice auger as mentioned above, my boat outboard motor, and my grain truck.
- I have a Stihl 028 chainsaw I bought in 1985 when I was logging professionally. I used it in that capacity for about 5 years. Since then, I only use it once or twice a year. The gasoline that I have for it is kept in an old antifreeze bottle in my shed. I kid you not, the gasoline that is in that bottle has been 2 to 3 years old at times and still worked fine. I used that saw just a couple weeks ago in fact.
- I have an old Montgomery Wards (original company) garden tiller that I use only once or twice in the fall. I've had it for over 30 years and it was used when I got it. I currently store it outside by my garden. Last week I wanted to give the garden a once over before winter. I set the throttle to full, pulled the choke, and pulled the recoil rope twice and it was running. As a side note, I have never replaced the spark plug so it too is probably the original.
- My push lawn mower is one that I got from my mother back in around 1995. I do not know how long she had it. I maybe use that mower once or twice a year to cut grass around a door by our pole shed or cut the peonies in the fall. It always starts and runs within just a couple pulls after priming it about 3 times. As a side note, I have never replace the spark plug on this either so it too could easily be the original.
- My 2012 Cub Cadet riding mower is my primary mower so I do use that regularly during the summer months. I store it in a 3-sided lean-to shed with the opening on the south side. It starts and runs very well.
- I have a 2008 Kawasaki ATV that I keep in the lean-to next to my riding lawn mower. I do use that somewhat regularly year round. It too always starts and runs flawlessly.
- My boat is powered by a 2012 90hp Evinrude E-TEC outboard. It is stored in a lean-to on the side of one of my outbuildings. This one I do put fuel conditioner in prior to winter storage. I really don't know why. I started doing that to protect the 5-year warranty and have continued ever since. So far, I have been very satisfied and impressed by that motor's performance.
- My 1947 Farmall M tractor is used somewhat regularly year around. Summer for planting seed and baling hay. Winter for blowing snow. It is very reliable and a good runner, although right now I need to put new points and condenser kit in.
- My 1968 Chevy C10 grain truck with its 427 and a Holley 4-bbl carb is used to make about 1/2 dozen trips per year to deliver my farm crops to market. When I got that truck, it had been in a storage shed unused for about 12 years. I did have to have the carburetor cleaned in a sonic bath along with new fuel lines that were decomposing, a new battery, and some brake work. Aside from that is has been working just fine. I do try to start it at least once every couple months throughout the year and let it run up to running temp to use the battery and lubricants.
Note: The chainsaw, garden tiller, push lawn mower, M Farmall, and grain truck were all manufactured before we went to unleaded and ethanol blended gasolines. I remember when leaded gas was eliminated and how the rumor mill was that engines would suffer. While there may have been a handful of incidents, that never happened to any degree. Same thing when ethanol was added. The scare was that carburetors would have to be rebuilt. Except for some snowmobiles and other machines with the various diaphragms in the carbs that required changing, that too never became a problem.
When I first got my M Farmall I was wondering about using 87 octane unleaded ethanol blended fuel. I decided to use a lead substitute until one day I happened to read the ingredients on the bottle. It didn't say "petroleum distillates" as I was expecting. In fact, there was only one word listed as ingredients....kerosene. I couldn't believe it! I was paying $5.00 per quart back in 1994 when I could buy kerosene for $1.35 a gallon at my local service station. What a rip off!! Needless to say, I discontinued using a lead substitute.
So, bottom line is, except for one incident, I have never had any issues using 87 octane unleaded ethanol blended fuel.
