Ethanol in gas for mowers- is it really bad?

[rigoletto]

Issue of using 87 octane is unresolved? Maybe not for you but it is for me.

Fine- your choice/decision. A few posts swearing by 93 is not evidence for me. The true power of knowledge is knowing that you dont know.

 

[Ric]

Fine- your choice/decision. A few posts swearing by 93 is not evidence for me. The true power of knowledge is knowing that you dont know.

Yeah it's my choice to run 93. What I do know and the evidence to me is that in the eight years of running my business and equipment daily it has never been in the shop to have anything done and I never had to have a carb cleaned or repaired, only things done are the normal maintenance like plugs and air filters and I do those myself.

All I own is Stihl equipment except for my Echo Bed definer so I couldn't run 87 octane in any of my Stihls if I wanted to because the manuals says to use mid-grade unleaded gasoline with a minimum rating of 89 (R+M2) and if it's not available to use premium unleaded fuel. It also says Fuel with a lower octane rating may increase engine temperatures. This in turn can increase the risk of piston seizures and damage to the engine. I guess the true power of knowledge would be to read the manual. :wink:

 

[PVHIII]

Nothing but 93 octane non ethanol fuel and Royal Purple 10W-30 in my Fast Trak SD...no problems whatsoever.

 

[bertsmobile1]

Thanks. But this "top tier" thing- hate to say it, but Im very suspicious about top tier concept. All gas in a specified octane is the same(except for the added ethanol), comes from the same pipeline from Texas, ends up in southeast, and one way up in NJ somewhare. All trucks fill up at the terminals, and then they "brand" it.

Still, my manual says use 87 octane, so why should I use 93? Like using 93 octane in a car that specifies 87. Roads are full of people puting in 93 octane "high test" , when they are doing nothing "better" to their cars even though their cars specify 87.

all posts appreciated, as the more the better.

Much like oil, "Fuel" WHICH IS NOT PETROL all start out the same.
So the refinery pumps out "base gas".
The tankers then fill up with "base gas" to which they add an addative package as a concentrate which mixes up with the base mix so by the time they dump it into the undrground tanks it is fairly well mixed.
Each brand has their own secret formula which will vary with the seasons & altitude that the fuel will be sold from.
It is a lot more complicated than it looks.
So while you might see 5 different fuel brands comming out of the same gate they will all be different.
Down here we only had 1 refinery in each state except NSW so rather than truck fuel 2000km each refinery used to do all the brews, much like those old Amoco stations that had the mixing pumps.
So no conspiracy just some mutual co-operation in order to maximise profit.

 

[bertsmobile1]

Would you explain " burns hotter " .

Every flame has a unique flame temperature
Usually the higher the octane the higher this temperature is
This is assuming a full burn in a balanced air fuel ratio.
Thus 93 will burn hotter than 87
However 97 also burns slower than 87
Much the same as butane ( lighter fluid ) burns slower than propane ( BBQ Gas ).

Thus a motor running lean on 93 will run a lot hotter ( exhaust gas temperature ) than the same engine running lean on 83, provided all the fuel is actually burned, which it seldom is which is why we fit an after burner , commonly called a catalytic converter to disguise its real purpose, to our car engines.

However it gets more complicated because the amount of heat is dependant on a lot more than just the temperature of the flame.
The flame on your stove is the same temperature no matter how far you turn it up or down but the amount of heat available to boil the water for you cuppa will vary.
The same applies to your engine, so burning a hotter fuel might not necessarily make the engine run hotter but it will make the exhaust hotter which will not make the exhaust valve & seat very happy.

While ethanol does not actually "Pull water out of the air" it does concentrate the water that condenses inside the fuel tank and the ethanol / water mix then drops out of solution in the "fuel" ( called incorectly phase seperation ) and sits on the bottom of your float bowl / tank. This mix unfortunately supports bacteria which is the fluffy white goop you get in your carby bowl. The resaidue from the bacteria ( urine if you like ) is quite acidic which is why it rips the zinc coating off your float bowl which not only rusts but also supports sulphate reducing bacteria which is the mid yellow / brown sticky stuff further clogging up the carb.
This is analogous with the old problem of alge growing in deisel tanks.

So while ethanol fuel mix wil not hurt your engine while it is fresh and running, it is when you let it sit for long periods that it becomes a problem except for the few diaphragm carbs still running the original synthetic neoprene over silk diaphragms , polyester or unstabilized brass ( jets) componants which have not been in production for around 20 years now so should all have been replaced.

 

[loco-diablo]

There are no ethanol free gas stations in my area at all. I've been using the 87 octane, 10% E blend w/ a splash of seafoam for years in ALL my equipment, Zero issues.
As long as you keep it fresh. I poor what's left in the can into my truck every 2/3 weeks and refill the can.\
The most important thing is getting it ALL out of the machine when storing.

 

[Smith97454]

Arent the fuel filters on these mowers filtering out some of the water in the fuel? Also wouldn't running some carb/fuel injector cleaner in the fuel occasionaly help prevent any sludge or gum deposits?

Also on the 93 vs 87 Debate. Some of the brands of 93 out there have some added detergents in the higher tier fuel. Not sure if it matters much but I know shell is supposed to have some cleaning agents in their 93 octane which is like running injector cleaner in the tank. I can't specify on a small engine if it matters much though.

 

[Ric]

Arent the fuel filters on these mowers filtering out some of the water in the fuel? Also wouldn't running some carb/fuel injector cleaner in the fuel occasionally help prevent any sludge or gum deposits?

Also on the 93 vs 87 Debate. Some of the brands of 93 out there have some added detergents in the higher tier fuel. Not sure if it matters much but I know shell is supposed to have some cleaning agents in their 93 octane which is like running injector cleaner in the tank. I can't specify on a small engine if it matters much though.

The Fuel Filters you'll find on mowers are not going to filter out water. there basically nothing more than rock catchers as we used to call them. They do make filters that will separate water from gas but there super expensive and I don't really think they make them for a lawn mower engine. If you use a good quality fuel like the Shell gas you should have to worry about water.

 

[Bod]

The Fuel Filters you'll find on mowers are not going to filter out water. there basically nothing more than rock catchers as we used to call them. They do make filters that will separate water from gas but there super expensive and I don't really think they make them for a lawn mower engine. If you use a good quality fuel like the Shell gas you should have to worry about water.

Agreed, a 40 mic filter will stop water for around $8. But then that causes more probs unless you change/ empty the filter often. Normally if an engine is used often the water prob takes care of it's self simply cause the fuel that you have in your can is fresher.

 

[Ric]

Agreed, a 40 mic filter will stop water for around $8. But then that causes more probs unless you change/ empty the filter often. Normally if an engine is used often the water prob takes care of it's self simply cause the fuel that you have in your can is fresher.

The problem you would have is the filter size. It would have to be as large as the spin on oil filter you run on your mower, enough to hold gas and water separately and filter elements which separate the water as well as remove any contamination. My guess is that it wouldn't be cost effective on a mower, that's why the manufacturer doesn't install them.