does higher octane gas help?

302w

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Aug 3, 2003
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i was wondering if running a higher octane gas gives you better performance?
 

lonewolf5347

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Jun 11, 2001
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Re: does higher octane gas help?

Today egines will run on 87 octane my manual on my 2003 yamaha say min. octane to be used is 87,I myself use 89 octane.I did notice when I had my force 120hp outboard 89 octane there was better performance than using 87 octane.
 

302w

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Re: does higher octane gas help?

i have allways ran my 89 150 yammy on 93 octane. just wondering if it was worth it.
 

Navigator

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Re: does higher octane gas help?

302W,<br /><br />There was a HUGE discussion on this very topic about 9 months ago, give or take. Use the search tool and search on "Octane".<br /><br /> Basically, in summation, you only need to use higher octane in your engine, if the mfgr requires it. Higher octane fuel is not "Better" than lower octane fuel, It's simply a different mixture. 93 octane has a higher flash point than 87. It primarily was designed for high RPM, High compression engines who needed a higher flash point than 87 gave. Running 87 in an engine designed for 93 would ignite prematurely due to its lower flash point. In cars, this is called "Engine Knock". 2 Strokes dont use valves so this isn't an issue. There is a possibility that an older engine may experience preignition in which case boosting the octane up will help that scenerio. (I too had an old Force which I had to run 89 in to get it to work right) But this is only a remedy to cure a specific problem. <br /><br />You are not boosting your performance of your engine by running 89 or 93 if your engine is designed to run on 87. You are simply paying more, thats all. (its not hurting anything either) If your engine was designed to run with 87 octane, then the best thing you could do is give it FRESH 87 octane fuel with a good quality oil. (Save the few pennies and use it to take the wife out to eat :D ) <br /><br />Ans stay away from the methanol type fuel mixtures. They'll harm the engine.<br /><br />If you want to know the specifics, search for the old thread. It got into chemical compositions and combustion principles along with the US oil industry and everything in between.<br /><br />Hope this helps,<br />Nav :cool:
 

302w

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Aug 3, 2003
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Re: does higher octane gas help?

Whats your opinion on fuel additives that say they clen your engine?
 

Miss Rita

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Nov 4, 2002
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Re: does higher octane gas help?

I didn't know my engine was dirty! It seems that most major oil companies have their own version of a detergent additive that keeps the engine clean already. If it ain't dirty, don't clean it!<br /><br />I'll admit that I had good luck using BG44k gas additive in a Porsche 911 SC that had been stored all winter without a gasoline stabilizer.
 

Navigator

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Feb 6, 2001
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Re: does higher octane gas help?

302w,<br /><br />I'm against most fuel additives that are designed to "clean" the engine. These additives contain chemicals to dissolve gunk deposits in the engine. Since these gunk deposits are basically oil and dirt mixtures, these additives are designed to break down the oil to free up the dirt. <br /><br />Since 2 strokes mix the oil and gas, you are basically breaking down the lubricating properties of the oil with the additives therefore drastically shortening the life of your engine. If you notice, all outboard 2 stroke oil is TCW-3 and contains "No Detergents".<br /><br />The only additive I use for my 2 stroke gasoline is fuel stabilizer.<br /><br />Nav :cool:
 

302w

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Aug 3, 2003
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Re: does higher octane gas help?

what brand of 2-stroke oil do u recommend? i have a 150 yammy 89
 
D

DJ

Guest
Re: does higher octane gas help?

302,<br /><br />In a nutshell, running higher than recommended octane fuels tends to lead to combustion chamber deposits. That is the kiss of death in a 2-stroke.<br /><br />As far as engine cleaners go, the only true way to clean the 2-stroke engine is to "decarb" it. Do a search on decarb.<br /><br />Any premium TCW-3 rated 2-cycle oil will be fine.
 

Navigator

Chief Petty Officer
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Feb 6, 2001
Messages
517
Re: does higher octane gas help?

Like Djohns19 said,<br /><br />Any premium TCW-3 oil is fine. I personally use Quicksilver, but only because I have a nice Mercury dealer about a mile away.<br /><br />Nav :cool:
 
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