Can you add Octain Booster to fuel on a outboard motor

[Mo.CrappieFisherman]

I have been told to add octain booster to my fuel as well as premium gas. I thought you could and a couple people i fish with say they do, but I was not sure it is safe. What do you all think?

 

[Paul Moir]

Re: Can you add Octain Booster to fuel on a outboard motor

For your '82 Evinrude V-6?? Run regular (87 octane) gas and don't listen to whoever buddy is. Both premium gas and octane booster are bad ideas.

 

[ZmOz]

Re: Can you add Octain Booster to fuel on a outboard motor

Yeah, you need to run the lowest octane your motor was designed for - that's 87 for most outboards. The crap in the tiny little bottle that says octane booster at most parts stores is completely worthless in anything. You need to add GALLONS of liquid to bring up the octane any noticeable amount. When the bottle says it raise the octane 5 points they mean from 87.0 to 87.5. That does alot of good...

 

[Paul Moir]

Re: Can you add Octain Booster to fuel on a outboard motor

Pardon a quick hijack Mo.CrappieFisherman, but I wanted to ask ZmOz what he ran in his I-6. I've heard they work better with mid-grade or maybe premium. Is this the case? Or is it a set years thing?

 

[Mo.CrappieFisherman]

Re: Can you add Octain Booster to fuel on a outboard motor

Yes i have an Evinrude V-6 150hp. So it is best to run 87 octane? It seemed to run better when i used premium though. More power out of the hole, and a lot smoother at idle it purred like a cat. I just did not know if octane booster would help or make things worse. Let me know what you think. Thanks for you input so far.

 

[trog100]

Re: Can you add Octain Booster to fuel on a outboard motor

running a higher octane fuel in an engine than it needs wont do it any harm.. it wont make it run better either..<br /><br />if your engine knocks or pings under load u need a higher octane fuel.. if it dosnt u dont..<br /><br />folks that run a higher octane fuel than is recommended are just playing safe.. it wont do any harm.. however running too low an octane fuel will soon wreck your engine.. <br /><br />putting premium grade fuel in am engine that dosnt need it is just wasting money.. it wont do it any harm thow.. and in some ways it is playing "safe"..<br /><br />trog<br /><br />ps.. and folks that think running a premium grade fuel in an engine that dosnt need it makes it put out more power or go better are kidding themselves.. its all about a fuels anti-knock properties nothing else.. its quite a common belief thow..

 

[Mo.CrappieFisherman]

Re: Can you add Octain Booster to fuel on a outboard motor

so trog100 do you think i needed the premium then because it ran better at idle at gave me better out of the hole power?

 

[Pony]

Re: Can you add Octain Booster to fuel on a outboard motor

I think i need to disagree with trog100.....<br /><br />The higher Octane probably will do harm to your motor, and most certainly wont do any good. Its not in my opinion playing it safe by any means. I think (experts correct me) that higher ocatanes can cause a lot of predetonation problems. Higher octane can and will coke up your rings and would probably cause ring failure at some point down the line, could very easily mean rebuild. Save your money, more importantly save your engine, and just run 87 octane at 50:1<br /><br />The only things that I would ever add to my gasoline is seafoam and stabil....beyond that its probably only doing a lot more harm then good.

 

[QC]

Re: Can you add Octain Booster to fuel on a outboard motor

Originally posted by Pony.:<br /> I think (experts correct me) that higher ocatanes can cause a lot of predetonation problems.

Exactly the opposite. Trog is correct. Octane is a measure of RESISTANCE to knock which is also related to pre-ignition, but not necessarily the same thing. Anyway, if your engine knocks or pings at all, you MAY need higher octane fuel. It may also be a timing issue or a host of other things. But if your engine that is in decent shape and tune, does not knock or ping, then higher octane fuel is a waste of money.<br /><br />I don't know why it would run and idle better on higher otctne fuel. All I know is that my cars seem a little faster when they are clean . . .

 

[stevens]

Re: Can you add Octain Booster to fuel on a outboard motor

The way I've understood it, a higher octane fuel needs higher compression to ignite. In other words, less risk of predetonation (but no point if your engine doesn't need it).<br /><br />The guys who think their engines ran better on higher octane fuel may be right, but not necessarily due to the higher octane in itself. The fuel they ran could also have contained a better additive package, or be fresher or cleaner in some way. Also, their engines may have been newer, cleaner or better tuned at the time.

 

[Dunaruna]

Re: Can you add Octain Booster to fuel on a outboard motor

BINGO @ stevens!<br /><br />To confuse the subject even further, octane ratings are NOT universal, some countries use RON, some use MON and some use DON. The US of A use DON, which is an average of the RON & MON reading. 87 octane (DON) in the U.S is about 92 (RON) octane in Australia & Europe.<br /><br />Aldo

 

[trog100]

Re: Can you add Octain Booster to fuel on a outboard motor

the fuel/air mixture is compressed under an engines "compression" stroke before its ignited by the spark from the plug.. <br /><br />the more the fuel mixture is compressed.. the more power is obtained on the power stroke.. however compress it too much and it will detonate or go off on its own without the spark.. this is how diesels work.. detonation is bad news.. instead of a progressive slow burn the fuel literally explodes.. this is what pinging is and its what will damage your engine..<br /><br />the higher the engines compression ratio the more power it will develope but the higher octane rating fuel will be needed to prevent such detonation..<br /><br />so called premium fuel has the highest octane rating and will be the least likely to detonate under any circumstances period.. thats why some consider it a safe option.. <br /><br />just for interest.. i am old enough to have used leaded fuel.. my I/O 3.0L merc engine is supposed to run on regular 95 RON unleaded gas..<br /><br />but.. back in the days when similar cast iron headed overhead valve engines were common in cars.. with over a 9 to 1 compression ratio such an engine would have been considered to be pushing the limit compression ratio wise and would have been run on 100 octane fuel or at least 98 mimimum..<br /><br />if 98 RON fuel was available today i would use it in my boat.. okay modern cars are designed to run on todays lower octane rating fuel so might "modern" boat engines be (is there such a thing) but my 1960s design GM cast iron high compression boat engine wasnt.. it would have been run on the highest octane rating fuel available back then..<br /><br />the bottom line is if your engine pinks.. knocks under load or runs on when u switch it off it will benefit from a higher octane fuel.. if it dosnt do any of these things it wont..<br /><br />they do still make decent 100 octane rating fuel.. its for airplanes and it still has lead in it..<br /><br />of course whatever weird stuff they put in fuel now in an attempt to keep the octane rating vaguely high enough to be useable is completely unknown to me.. i think its pretty evil stuff thow which is the only logical reason i can see for todays lower octane fuel.. so there might be a good reason for not useing any more of it than u have too.. he he..<br /><br />trog

 

[QC]

Re: Can you add Octain Booster to fuel on a outboard motor

Originally posted by trog100:<br /> however compress it too much and it will detonate or go off on its own without the spark.. this is how diesels work..

Sort of. It is important to remember there is no fuel in the air prior to ignition with a diesel. They can't pre-ignite as there is no fuel in the engine until you want it . . .<br /><br />

Originally posted by trog100:<br /> detonation is bad news.. instead of a progressive slow burn the fuel literally explodes.. this is what pinging is and its what will damage your engine..<br />

Exactly, perfect, yes. A little clarification though. Pre-ignition is detonation before you want any burn, but detonation usually happens when the spark starts it, which is not technically pre-ignition. It is just plain detonation and still bad.

 

[Dhadley]

Re: Can you add Octain Booster to fuel on a outboard motor

We're talking about stock recreational motors. This means we're assuming the compression ratio has not been altered. <br /><br />Todays high octane pump gas in the US burns hotter than 87. Opposite of what it used to be with leaded or low lead fuel. In a carb'd 2 stroke outboard that means coking will occour quicker. That can lead to scuffed pistons and/or broken rings. Especially if the motor will only turn 5400 now. In a 4 stroke I/O the hotter burn is really hard on the valves. We see it all the time on the dyno and on boats with EGT gauges.

 

[JB]

Re: Can you add Octain Booster to fuel on a outboard motor

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