Fuel treatment/additives

[Astro180]

We had a big debate at work today about fuel treatment, additives and ethanol fuel. So I just wanted some input from you guys, do you add anything to your straight gas, do you run ethanol gas, and if so do you use any type of additives or stabilizer? I would rather run pure gas, but my merc prefers 93 over 87 and locally all the 93 has ethanol, so I have been using the Lucas ethanol treatment myself.

[rusty50576]

“Straight gas (cash) homie “ - randy moss haha

[SteveHTN]

My old Mariner Super Magnum EFI called for premium, and Merc’s advice was pure gas. The times I’d use E-blend, she wouldn’t run as well. But now I’ve got a Johnson Venom, with the carbs, and honestly I’ve just been running regular ole unleaded E-blend, and she’s doing fine. I just make sure to put some StarTron in. YMMV

[Astro180]

I'm going to try and find some straight 93 and see if it makes a difference. 

[Mountainman]

So.....all 2 stroke manufacturers currently advise pure gasoline & 87 octane(regular). Reason is 87 burns at a hotter rate, leaving less carbon deposits. Some of the older & racing 2.5 liter Mercs require mid (89) or high grade fuel(93) BUT state they would advise lower grade of pure gasoline over higher grade ethanol blend. Main factor to remember with ethanol fuel blends: be absolutely certain your fuel lines are the most up to date, ethanol resistant rated lines available. Otherwise, you will get line separation & have fuel system gunk problems. 4strokers are a different animal in that most (Yamaha, Honda, Suzuki) suggest mid grade (89) fuel. The engine will not produce the rated HP with lower than mid grade fuel. It will run fine, just won't produce as many horses. As for additives, Merc fuel system is a must on a black motor......Quickare, Quickleen & Quickstor(sub Stabil here) as a cocktail is the hands down, unbeatable blend. For 4 bangers, Yanaha's Ring Free plus Stabil makes a great blend. Also remember that gasoline starts to lose it's volatility after 30 days. If it's ethanol blend, at this point, it will start to draw moisture.

[31Airborne]

^^What Andy said.

Every Merc tech I've known says blue Sta-bil is the additive of choice if you have to  run ethanol fuel.  To a person they say run pure gas if you have the option.  I go out of my way to get pure gas for my sled.

[rusty50576]

Forgot to add mine is 50 hp 4 stroke 

[SteveHTN]

+1 what Andy said about the fuel lines. Morristown Marine saved my engine years ago, because I had an older gray fuel line, and the inside of it was eaten out by the ethanol and clogged the fuel filter. No doubt some gets by the filter. 

[Astro180]

13 hours ago, Mountainman said:

So.....all 2 stroke manufacturers currently advise pure gasoline & 87 octane(regular). Reason is 87 burns at a hotter rate, leaving less carbon deposits. Some of the older & racing 2.5 liter Mercs require mid (89) or high grade fuel(93) BUT state they would advise lower grade of pure gasoline over higher grade ethanol blend. Main factor to remember with ethanol fuel blends: be absolutely certain your fuel lines are the most up to date, ethanol resistant rated lines available. Otherwise, you will get line separation & have fuel system gunk problems. 4strokers are a different animal in that most (Yamaha, Honda, Suzuki) suggest mid grade (89) fuel. The engine will not produce the rated HP with lower than mid grade fuel. It will run fine, just won't produce as many horses. As for additives, Merc fuel system is a must on a black motor......Quickare, Quickleen & Quickstor(sub Stabil here) as a cocktail is the hands down, unbeatable blend. For 4 bangers, Yanaha's Ring Free plus Stabil makes a great blend. Also remember that gasoline starts to lose it's volatility after 30 days. If it's ethanol blend, at this point, it will start to draw moisture.

When you say older, what years would that be? Mine is a 96 merc 115, at this point in time would that count as an "older" motor? Also, in regards to fuel lines, i had them replaced last winter with some that are supposed to be able to tolerate the ethanol.

 

Thanks for the input everyone, I greatly appreciate it!

[31Airborne]

I believe the change to new, ethanol-resistant material took place in 2007-2008.  Anything before that would be considered 'old'.  Would be worth the time and effort to check out your fuel lines, filters.

[Astro180]

1 minute ago, 31Airborne said:

I believe the change to new, ethanol-resistant material took place in 2007-2008.  Anything before that would be considered 'old'.  Would be worth the time and effort to check out your fuel lines, filters.

I replaced both lines and filter last January.

[basskicker]

100 % gas only in my motor and I still put Marine Stabil  in every tank. You never know what you're getting out of the pump.  Right after I bought my boat it started acting like it was running out of gas and it ended up being bad fuel lines from where the original owner used ethanol gas. Ended up having to change all the lines , even some inside the motor. Luckily it didn't go boom when it happened. I was turning 6000 rpms and balls to the wall when it just about shut down. Scared me to death because there was no way I could afford  a new motor.

[Mountainman]

9 hours ago, Astro180 said:

When you say older, what years would that be? Mine is a 96 merc 115, at this point in time would that count as an "older" motor? Also, in regards to fuel lines, i had them replaced last winter with some that are supposed to be able to tolerate the ethanol.

 

Thanks for the input everyone, I greatly appreciate it!

You're asking about octane rating, correct? "Older", in this sense, is anything below about 2005-ish. Check with the manufacturer about recommended fuel octane rating. When in doubt, run regular (87). As I said, the higher the octane, the cooler it burns allowing for more carbon build up. Carbon build up is worse than a poor running engine or predetonation knock, although neither is good. Check with Merc on your serial number for recommendations on fuel grade. I read on BBC once, in order of importance:

1. High traffic, high volume stations

2. Correct fuel octane rating

3. Ethanol content(NOT to exceed 10%.....DO NOT USE E15 or higher!!!)

[MOONlite]

i've never blown an engine in 30+ years and i didn't have new stuff.

all i had were blown engines with melted pistons that i rebuilt.

i've always run 93 octane with seafoam or some carbon cutter every 3 or 4 tanks.

i sold 1 of these engines after running it for a while and the guy melted a piston with 87 octane.

while i was at watson's, all melted pistons i saw were running 87 octane.

gas these days goes bad very quickly so fresh is most important.

87 octane would be fine but you don't always get 87.

93 gives a safeguard and i bet most of it tests closer to 87.

the new 4 strokes should eliminate most of the melted piston problems typical of 2 strokes.

[SteveHTN]

I certainly don’t have a PhD in chemistry, nor am I an ethanol salesman, and from a practical standpoint I hate the stuff (takes more energy to make, at least in the USA with corn base, than you actually get out of it), but I don’t think it’s the big deal it once was. I think the fuel companies now have these blends down pat, and far more important is proper octane, and use of a fuel stabilizer for long term storage, since alcohol is obviously hydroscopic. As for octane itself, again I think it was much more of an issue years ago than now. I believe now those numbers are pretty daggum accurate. If anything, oil companies err on the side of caution now with octane ratings, as several scientific studies have shown- hence the YouTube videos, and online articles, about being able to run regular in cars that otherwise recommend premium. Yes, part of that is car technology, but part too is gasoline, and other fuel, is much more precisely refined nowadays. Now, let me clarify, I don’t see ethanol as a big deal from engine life standpoint nowadays, but performance wise, it obviously doesn’t have the same energy as pure gas. My .02 anyways 

Edited December 15, 2018 by SteveHTN

[softbaitmaker]

I went through all of this with a Yamaha Rep at the Yamaha factory when I got my 130 Yamaha on my 1998 Skeeter. The man was very polite and spent about 35 to 40 minutes with me on the phone. My first question to him was is my 1998 Yamaha ethanol safe and he said let me pull up your motor and he pulled it up so he could be sure to answer my questions. His answer was yes, your 1998 130 Yamaha is ethanol approved and it has all the ethanol approved fuel lines. My next question to him was what octane is recomended for my motor and he said I would get the best performance if I ran the 87 octane fuel as that onboard computer is sent to run 87 octane and running anything higher would not hurt the motor but I would be actually wasting money paying for the higher octane because I would not get as good a performance because the motor was programed for 87. I have been running 87 since 1998 and I also use Blue Sta-bil with every tank of fuel and I have not had any issues at all fuel related and the Skeeter is now 20 years old with a 20 year old motor. Before we put it up for Winter this year we took it out and ran it till we could fill the tank with fresh 87 fuel and the blue Sta-bil. Took it back the lake, ran it about 10 minutes till the Sta-bil and new fuel would be in the entire fuel system and put her up for the winter.

I have been doing that same routine for the last 15+ years and when I bring her out in Spring I put muffs on her and start her here at the house and it will turn over about 8 to 10 times and fire right up and go on high idle like normal. I will say this. I knock on wood every Spring before I turn the key the first time.................

[Astro180]

5 minutes ago, softbaitmaker said:

I went through all of this with a Yamaha Rep at the Yamaha factory when I got my 130 Yamaha on my 1998 Skeeter. The man was very polite and spent about 35 to 40 minutes with me on the phone. My first question to him was is my 1998 Yamaha ethanol safe and he said let me pull up your motor and he pulled it up so he could be sure to answer my questions. His answer was yes, your 1998 130 Yamaha is ethanol approved and it has all the ethanol approved fuel lines. My next question to him was what octane is recomended for my motor and he said I would get the best performance if I ran the 87 octane fuel as that onboard computer is sent to run 87 octane and running anything higher would not hurt the motor but I would be actually wasting money paying for the higher octane because I would not get as good a performance because the motor was programed for 87. I have been running 87 since 1998 and I also use Blue Sta-bil with every tank of fuel and I have not had any issues at all fuel related and the Skeeter is now 20 years old with a 20 year old motor. Before we put it up for Winter this year we took it out and ran it till we could fill the tank with fresh 87 fuel and the blue Sta-bil. Took it back the lake, ran it about 10 minutes till the Sta-bil and new fuel would be in the entire fuel system and put her up for the winter.

I have been doing that same routine for the last 15+ years and when I bring her out in Spring I put muffs on her and start her here at the house and it will turn over about 8 to 10 times and fire right up and go on high idle like normal. I will say this. I knock on wood every Spring before I turn the key the first time.................

Thanks for the input....I am starting to eliminate all these things a piece at a time. As i stated earlier, i replaced the filter and lines last January. I took the boat out tuesday and ran out what fuel i had and filled her up with fresh PURE gas and some stay-bil for the winter.....OR until i cant stand not fishing anymore which is probably more accurate!😁😂

[Hoss]

I have been running 87 in my boat for 4 years with Quickleen and Quickare. Not a single problem. Avoid Seafoam as it contains alcohol and will attract water. The damage some from the older dual lines can't be seen because it deteriorates from the inside out. There are plenty of people who run nothing extra and never have a problem. To each their own but I would rather be safe than sorry. Carbon buildup can be expensive.

[Astro180]

On 1/12/2019 at 12:55 PM, Hoss said:

I have been running 87 in my boat for 4 years with Quickleen and Quickare. Not a single problem. Avoid Seafoam as it contains alcohol and will attract water. The damage some from the older dual lines can't be seen because it deteriorates from the inside out. There are plenty of people who run nothing extra and never have a problem. To each their own but I would rather be safe than sorry. Carbon buildup can be expensive.

That is one SWEET looking boat you've got there.

[Hoss]

On 1/18/2019 at 9:04 AM, Astro180 said:

That is one SWEET looking boat you've got there.

Thanks....