Outdoor Power Equipment (Lawn Mowers, Snow Blowers, Chain Saws and more) Discussions

Happy holidays every one! ... bought the toro 1028 OXE back in October, right after the very first early snow storm. Was not able to try it in snow... I added the startron stabilizer And filled up the tank with 93 octane. I tested the new baby, showed off without spinning augers... But now it's a long time unused. My question is: is it okay for the fuel to sit in the carb for such a long time? Thanks!

Well, I own probably 40 pieces of equipment from OPE, to outboard motors, to ATVs, to snowmobiles, to motorcycles, to cars and trucks.  Never an issue with stale fuel. 

However, I do proper maintenance and drain fuel from equipment that will be stored for long durations.  Nonetheless, I still keep fuel in plastic five gallon containers at my camp for six to eight months and it works just as fine as fresh fuel.  So, the stories about fuel going bad in one month sound a bit contrary to my experience. 

I would wager that the stale fuel your customers experience is much more than 30 days old and likely much older.   I would also wager that it was kept in a fuel tank that was left less than 1/4 full.  Under those conditions, it has room to evaporate and deteriorate.  If their tanks were kept either right empty or completely full before storage, and they ran their carbs dry, they probably would not have had a problem.

And I stopped using stabilizers ten or fifteen years ago.  Haven't regretted it yet.

And for all the 40 engines you use regular 87 octane?

For example just last week i had a 2008 ariens come in NO START the lady says she started it a couple of months ago to move it in the garage... went to start last week and it wont start.. this is a tecumseh 6hp ohv...anyways all i did was drian the old fuel out and put new in and it started first pull.. and this could of been pervented if she used stabilizer..of course she had no idea what stabilizer even is.. and thats a good example of a snowblower that started only a couple months of ago.. of course lm not saying that will happen to every snowblower but is it worth the risk for a couple of dollaurs for stabilizer??

And for the customer sake its just makes things easier then they dont half to remember "should i leave fuel in it" "half or full" "how long is fuel good for" all these questions are gone if they just use stabilizer, then they have no worries at least in regards to storage and fuel..

most new briggs mowers are coming with stabilizer (replacable cartiridge) built in the fuel caps...because they've had so many problems with stale fuel causing no starts... it just makes sense.. thats my opinion.

JoelKlein wrote:

 

The octane rating of gasoline tells you how much the fuel can be compressed before it spontaneously ignites. When gas ignites by compression rather than because of the spark from the spark plug, it causes knocking in the engine. Knocking can damage an engine, so it is not something you want to have happening. Lower-octane gas (like "regular" 87-octane gasoline) can handle the least amount of compression before igniting.

The compression ratio of your engine determines the octane rating of the gas you must use. One way to increase the horsepower of an engine of a given displacement is to increase its compression ratio. So a "high-performance engine" has a higher compression ratio and requires higher-octane fuel. The advantage of a high compression ratio is that it gives your engine a higher horsepower rating for a given engine weight -- that is what makes the engine "high performance." The disadvantage is that the gasoline for your engine costs more.

In a low compression engine(8:1), it is sufficient to burn low (87) octane fuel because the heat of compression is not high enough to ignite it spontaneously. However, as compression is raised, higher octane ratings are necessary to prevent this auto-ignition. Since higher octane gasoline burns at about the same temperature as low octane, it generates the same amount of power. The reason a high compression, high octane engine develops more power is because the higher compression raises the BMEP--Base Mean Effective Pressure: More pressure = more horsepower. Timing is usually advanced a bit also for a better power curve and the engines are usually adjusted to injest more air/fuel mixture. They also usually produce this power at a higher RPM than a low compression engine. THUS: There is NO advantage to using high octane fuel in an engine that requires low octane, and at best, it is a waste of money. Indeed, some high octane fuels can contain compounds that could be harmful to low compression engines.

However, using low octane rated fuel in a high compression engine is harmful. Because the gasoline auto-ignites at a different point than the sparkplug and usually earlier, there are two flame fronts burning. When the flame fronts collide, excess temperature and pressure are generated. We may hear it as a knocking noise also known as "detonation." This melts the aluminum of the piston while at the same time hammering it. Total destruction is the result.

Conclusion: Use fuel with the octane rating recommended by the manufacturer.

Lean running conditions are a separate scenario not related to octane rating. Lean fuel mixtures also auto-ignite more easily and burn hotter than proper mixtures of gasoline and air regardless of octane rating. The result, however is the same: Total destruction of the piston.

Okay, I fully understand why we cant use 87 octane in a high performance engine without damaging it. . But you still didn't explain why we can't use 93 octane In a low Compression engine! You wrote that it may Contain some elements, what are those elemants? To worst it can happen is $$$$ in trash! But damage???? Or make it perform worse?!

Simple 93 octane burns hotter, in a car this isn't much of an issue but in a small engine it could be. Also elevation affects engines and you need less octane or something bad happens.

The safest thing you can do is run the right gas. In my Toro 1028 I run 87 octane from the local station. This works. If you already have 93 octane I guess run it until it you run out then

buy 87 octane. Save your money. I can't imagine it doing any damage in the short term.

Yes.  I use the least expensive pump gas I can find in all of my engines.  Never had a problem. 

Don't forget what the fuel prices are like in this country.  Right now, at some places regular 87 octane gas  is $1.30 a liter.  That works out to about $4.90 a U.S. gallon.

Using higher octane than recommended by the manufacturer will not damage your engine. There are no advantages to using higher octane than recommended by the manufacturer. The only difference between higher octane and lower octane is the ignition temperature. Use whatever octane fuel you wish to use as long as it meets the minimum octane requirements of the engine manufacturer. The one change you will see when using higher than recommended octane fuel is a lighter wallet. Regarding where to buy fuel, there are very few low volume gas stations anymore. The sale of gasoline is a low margin business. That is why it is sold mostly at stores with multiple sources of revenue, i.e. convenience store, restaurant, car wash, souvenir shop. It is very rare to get old gasoline out of the pump. The majority of gasoline is at most a few days old. All the gasoline within a fixed area comes from the same refinery. The refinery formulates the various octane grades of gasoline then adds the additive package of the particular company when filling the tanker truck. You will see tanker trucks from every gasoline company pulling in and out of your local refinery. So picking one gasoline company over another means you are picking one additive package over another but the basic gasoline is all the same within a given geographic area.

JoelKlein wrote:
Due to its design high octane fuel is designed to to ignite at higher compression levels as to not detonate or auto-ignite in a high compression engine.  It also has a slower burn rate and a slower moving flame front.   This will cause a loss of power in a lower compression engine as the fuel will start to burn later and will be burning slower, still burning after the piston reaches BDC, effectively reducing the amount of power extracted out of the fuel. You could advance the ignition timing to help solve this problem but you still wont get any more power out of the engine. The net result will be wasted unburnt fuel, loss of power, and even carbon buildup on the exhaust valve that after a while will lower compression even more due to the valve not being able to seal the combustion chamber.

I suggest you run what ever octane you like in your engine, however, running 93 octane in an engine designed for 87 is not only a waste of money is will surely cause a stock low compression engine to loose power and even carbon up.  Did you ever hear the saying  use the right tool for the  job.  87 octane is the right tool for a low compression engines period.

Higher compression engines require higher octane to prevent Pre-ignition/detonation.

I have been running 87 octane fuel in my small engines for over 30 years with no problems.

If you want real high octane (short of buying racing fuel) gas get some 100LL (available at small local airports) it even still has tetraethyllead in it.

I run Avgas  (100 LL) in my 11.8 compression 434 cubic inch 69 camaro which makes over 625hp at the rear wheels.  It has a very sweet smell  when burned and is blue in color

This is my technique for the past two years.  I don't use any fuel stabilizers on 87 octane fuel.  I try to fill up with enough gas per snowblower session, and run the carb dry if possible by shutting off the fuel valve.  If any of the gas in the external tanks is older than 30 days, I put the in the wife's car, then get fresh fuel.

So far so good.  I don't feel like spending money on fuel additives or higher octane fuel if I don't have to.  If it works for me, I will keep doing this until I see any problems.

Also, like Borat has mentioned before, if you must store fuel in the tanks for extended amount of time, fill it up to the top as much as possible reduce air volume in the tank, keep the cap tight.  This is the recommended method for metal gas tanks or cans, to prevent rusting.

Anyways, if you feel like spending more for additives or octanes gives you the warm and fuzzy feeling, that's fine with me.  This sometimes can create a "stimulus package" to the economy, a monetary policy, which has indirect benefits.  Sometimes people spend money on intangible, immeasureable, or neglible "benefits".  Everybody's perception is different so if you "perceive" the benefits, by all means do it.  I used to spend $1000 on speaker cables, I can't say I appreciate or notice the difference these days, but back then, it was worth it to me.  :)  Not that the $1000 speaker cables sounded even at least 2 times better than a $100 speaker cables, that was never the case.  Mankind can only do so much to create the perfect copper crystalline structure.  :)  And you'll be amazed how a glass of red wine improves the sound quality of any system.

Still waiting for snow here too.  There hasn't been significant snowfall to even break out a shovel.   The weather has been like early April, lots of rain.