Using 100ll av fuel in a 2-stroke outboard

[ole man of the river]

Will this fuel harm my 2000 9.9 johnson outboard when properly mixed with two cycle oil? I have been using av fuel for years in my standby wisconsin generator without any problems. I have had issues with ethenol in stored fuel that I got from the local gas station. The only reason I am considering it for my outboard is shelf life. Getting tired of discarding the outboard fuel after sitting for a year. Even ruined a good stihl chainsaw once with old fuel even though it was treated with sta-bil.

So whada ya think?

 

[steelespike]

Re: Using 100ll av fuel in a 2-stroke outboard

We are in the north east.
I don't know the difference in the aviation fuel.I have a 10 year old poulan chain saw that is
used about 30 min a year with the only special treatment is fresh 87 octane fuel in the spring maybe I'm on borrowed time.Allways starts easily and idles smoothly.
Lawn tractor and snowblower gets the same treatment with an oil change and gear lube thrown in.If the aviation is 100 octane I would think it may effect performance.Not likely to cause problems for a long time if you seldom use the motor.
I'd be inclined to stick with 87 and stabil and just use the suspect fuel in a car or lawn tractor/snow blower.If you mix 1/2 tank or 3 gal at a time thats less to have to use or discard.A 9.9 will run over 3 hours on 3 gal. at wot.
At present our 87 gas is 10%.
Purchased a boat well known to me with a 65 Merc 500 a few years ago that had sat
over 7 years treated with stabil it started and ran fine on the old fuel that I soon added fresh to.I do suspect that if it has cork floats its probably on borrowed time.
Not sure what my point is but wonder how long your fuel sits and if it may be poor quality or exposed to extreme temps.

 

[Faztbullet]

Re: Using 100ll av fuel in a 2-stroke outboard

If your going to run "avgas" up the main jet in carb .002 over stock, the reason is "avgas" has additives and oxygenators that causes engine to run lean. That why when people put it in their vechiles they note the exhaust outlet is cleaner as it actually running lean.

 

[pecheux]

Re: Using 100ll av fuel in a 2-stroke outboard

I often use 97 octane with my 1981 Johnson 9.9 and I have not noticed any difference in performance.

 

[steelespike]

Re: Using 100ll av fuel in a 2-stroke outboard

Running 97 is pretty much a waste of your money.Higher octane fuels are actually harder to ignight.It certainly won't improve performance but you would have to have pretty sofisticated
measurements to tell any difference plus or minus.

 

[Dhadley]

Re: Using 100ll av fuel in a 2-stroke outboard

The LL av gas will not harm the motor but it also has a short shelf life. If you think it'll stay good for a year at a time, it won't.

 

[pecheux]

Re: Using 100ll av fuel in a 2-stroke outboard

I am actualy hoping there would be no ethanol in higher grade gasoline ... but I am not sure about this.

 

[Dhadley]

Re: Using 100ll av fuel in a 2-stroke outboard

Ethanol or no ethanol has little to do with shelf life of the fuel. Any fuel without some sort of stabalizer won't retain octane and will gum up rather quickly these days.

 

[ole man of the river]

Re: Using 100ll av fuel in a 2-stroke outboard

No ethanol is found in av gas. Ethanol is not good in gasoline. Besides it attracts moisture and is hard on rubber parts in the carbs. We are at 10% ethanol in my area on all grades at gas station pumps. The EPA is pushing for 15% in the very near future.
The stand-by generator I use has had the same untreated av gas in the fuel tank for 3 years, so I know it has a long shelf life. Av fuel is not the fuel to use under all circumstances but it is the best choice for engines that sit idle for longer periods.
And you dont want to run av gas in any engine with a catalytic converter.

 

[pecheux]

Re: Using 100ll av fuel in a 2-stroke outboard

I read that when using E10 or E15 fuel a higher grade gasoline is recommended. Ex: vehicule needing minimum 91 should use 93 if ethanol is added. Any opinion on that ?

 

[ole man of the river]

Re: Using 100ll av fuel in a 2-stroke outboard

I am actualy hoping there would be no ethanol in higher grade gasoline ... but I am not sure about this.

A couple years ago in my area only the lower octane gasolines contained ethanol. Now it's in all octane grades at the gas stations. I bought an ethanol tester a few years ago. Very simple to use, just fill with water to the water index mark, the fill with gasoline to the upper mark. Screw the cap on shake it a bit then let it settle for 5 min.
The back side of the glass vail has a scale for the amout of ethanol in the fuel being tested.

 

[DJ]

Re: Using 100ll av fuel in a 2-stroke outboard

100LL is INCREDIBLE overkill.

Octane is a function of the fuels ability to avoid "knock". That is very important in aviation AIR COOLED engines.

It doesn't apply to outboards.

Higher octane fuels run cooler and tend to leave deposits in engines not requiring the high octane. Those deposits are DEATH to a two stroke outboard.

Use 87 octane and dose it with alcohol fighting additives. I use Sea Foam in everything.

 

[Greg Mrozinski]

Re: Using 100ll av fuel in a 2-stroke outboard

I read that when using E10 or E15 fuel a higher grade gasoline is recommended. Ex: vehicule needing minimum 91 should use 93 if ethanol is added. Any opinion on that ?

Pech,

Octane rating deals with a fuel's ability to reduce knock or burn in a controlled manner. Higher the octane rating the better it burns. Where octane is raised by blending in ethanol the resultant mix has a lower output of energy per volume or less "bang" for your buck. So using a slighly higher octane fuel can help this but probably won't be noticable. However, for boats, moisture in the fuel dramatically reduces the octane rating because the water bonds with the ethanol, causing the whole mix more difficullt to burn. This is why you should treat all fuel in your boat to help prevent this from happening.

 

[jay_merrill]

Re: Using 100ll av fuel in a 2-stroke outboard

"100LL" avgas is NOT low lead by any other standard, It is low lead compared to previous aviation gasolines. I wouldn't run the stuff in anything else but a piston engine aircraft engine, or maybe an old carbureted muscle car.



???

 

[Jerry_NJ]

Re: Using 100ll av fuel in a 2-stroke outboard

I"ll "jump" in here rather than start a new thread... I think I am more-or-less on topic. That is gasoline, but not avgas.

I have read that ethanol (even 10%) will bring an early death to my 1997 9.9 HP Evenrude - then yesterday a neighbor said I should put some type of stabilizer in the gas to counter the ethanol. Does this make any sense? I can ask him again, but for now I recall him talking about two "colors" of stabilizer and that both are available at places like HomeDepot, he recommended only one of the colors. My concern here is can I add something to the current crop of service station (New Jersey) that will make it more acceptable for use in my outboard motor?
Thanks.

 

[Silvertip]

Re: Using 100ll av fuel in a 2-stroke outboard

If you use the forumn "search" feature and key in the word "ethanol" you will have enough information to make your eyes bleed. This topic has been discussed to death including your exact question. I have used E10 in everything with an engine since 1997 and have experienced no issues whatsoever. If you treat the fuel with Stabil or Seafoam your engine will live a long life. If it is an older engine, replace the fuel lines with ethanol tolerant lines and go boating.

 

[Greg Mrozinski]

Re: Using 100ll av fuel in a 2-stroke outboard

^^^^agree

 

[metriccrescentwrench]

Re: Using 100ll av fuel in a 2-stroke outboard

I have read that ethanol (even 10%) will bring an early death to my 1997 9.9 HP Evenrude

That's totally incorrect. Outboard manufacturers have been building their engines with ethanol compatible components for a lot longer than that. My 1990 engine's manual states that it's designed to accept 10% ethanol.

The EPA is pushing for 15% in the very near future.

Also not correct. It's Archer-Daniels-Midland and a group of other companies that profit from ethanol production that are pushing for E15. They petitioned EPA to certify that 15 doesn't harm newer vehicles, EPA did the required testing and stated that E15 is acceptable to use in newer vehicles. It'll be up to the petroleum companies to determine if they can make money selling E10 (which is still needed for older vehicles) AND E15.

 

[planeman]

Re: Using 100ll av fuel in a 2-stroke outboard

The LL av gas will not harm the motor but it also has a short shelf life. If you think it'll stay good for a year at a time, it won't.

Not correct...

AV gas has a near inefinate shelf life. People don't fly their planes everyday, or every month for that matter. AV gas is a good storage fuel to use.

On another note, octane rating is the fuels resistance to burning and pre-ignition. That's why drag racers use this so they can Jack ignition timing to the moon and also run high compression ratios. With marine engines being lower compression, you will probably notice a power loss on take off. There is NO reason in running an octane rating higher that what's recommended for your particular engine. Its actually not as efficient.