To all wondering about what type of gas

kev_79

Petty Officer 1st Class
Joined
Aug 5, 2001
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355
Believe it or not, my major in college was chemistry for about 4 semester's. That gave me about enough knowledge to know exactly what octane is for. For those of you who don't know, Octane is not an additive to make gas burn cleaner, nor do you rarely get better gas milage. It doesn't put out more power per pound compared to 87 octane, and this I promise you....You will never pay less for 93 vs. 87. Octane is the agent in gasoline that keeps if from igniting under heat and pressure. If you know how a diesel works, they use a low octane gas, so it will ignite under pressure. Especially on 4 strokes, if you hear a pinging noise, sometimes called a labor knock in the engine, while under load, you probably need a higher octane fuel, try 89 next. If you do experience this, you will most likely get better performance from higher octane fuel. On two strokes, the fuel isn't in the chamber long enough to matter, because the spark plug fires every stroke. Some of the high end FI, DI engines recommend 93 octane, if so then use it. This is because of the design of the engines and the way fuel is inducted. This makes them more powerful and fuel efficient. To all others not hearing a knocking sound, or one's running carburated 2 stokes, stick with the cheap stuff. If you wanna **** your money away, **** it down the race track! Good luck all, and keep the hammer down! :D :D :D
 

12Footer

Fleet Admiral
Joined
Mar 25, 2001
Messages
8,217
Re: To all wondering about what type of gas

Kevin is right on about octane. Stick with what is recommended. Octane is not an additive, however, the octane can be raised by adding stuff to fuel. Sta-Bil, Seafoam,<br />104Octane booster will all raise the octane.<br />The pinging or pre-detonation is the fuel igniting before it should.<br />Long story short, use the lowest octane number your builder recommends. If it pings,go up to the next higher octane number.
 

ODDD1

Lieutenant Junior Grade
Joined
Jan 23, 2001
Messages
1,054
Re: To all wondering about what type of gas

Kev..I agree with everything you have stated, if you assume FRESH fuel....Premix it an let it sit in an above ground [warm/cold daily cycle] fuel tank for 3 weeks an all your assumptions are out the window.....Everyone i have ever spoken with agrees on one thing...the chemistry changes with time/heat/oxydation....
 

kev_79

Petty Officer 1st Class
Joined
Aug 5, 2001
Messages
355
Re: To all wondering about what type of gas

Well, odd1, It may save you about a day or two, if you run 93 instead of 87. The real key is, run that puppy outta gas every day or so, do you agree? :D
 

dtro

Seaman Apprentice
Joined
Jul 9, 2001
Messages
43
Re: To all wondering about what type of gas

So I fish a lot of small lakes near my home, and don't use the outboard a whole lot. Are you saying I should only fill up the 6 gal a half? a quarter? It's a lot easier for premix to not fill it up each time, and not worrying about buying gas each trip. <br />How does ethanol fit in to this equation?
 

crazyray2

Seaman Apprentice
Joined
Jul 27, 2001
Messages
49
Re: To all wondering about what type of gas

I would feel comfortable keeping fuel 10-14 days in tank with no negative effects.....depends on weather......just close vent when not in use......additives are another matter.....some are not good for all the rubber and plastic parts of your fuel system.......be careful here
 

kev_79

Petty Officer 1st Class
Joined
Aug 5, 2001
Messages
355
Re: To all wondering about what type of gas

dtro,<br /> Since it is easier, I think to fill up with 6 gal, and put a pint of (Wal-Mart's tech 2000 if your smart) to get a 50:1 ratio, I would do that. If you don't use it a lot, then add a fuel stabilizer. What odd1 is referring to is the break down of hydrocarbon bonds. If the chains break down due to heat, time, etc. So your C8H18 will become C6H14, and you will no longer have octane, you will have hextane, and that isn't good. That should be enough chem jargon to keep you thinking for a while. <br /><br />So if you don't use it much, put some stabilizer in to to hold the chains together for approximately 3 months, so they state. Personally I have ran 6 month old gas before, and it didn't run like a bat outta hell, but it ran fine. Anymore questions, please feel free to ask. :D
 

ODDD1

Lieutenant Junior Grade
Joined
Jan 23, 2001
Messages
1,054
Re: To all wondering about what type of gas

Yes Kev, my boat gets filled up on the way to the lake...the closer to empty it is when i put it on the trailer, the better.....
 

kev_79

Petty Officer 1st Class
Joined
Aug 5, 2001
Messages
355
Re: To all wondering about what type of gas

oddd1 has the key, run her out every time you can! :D :D :D
 
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