octane????

just curious but what is everyone's recommendation on fuel octane??? goods bads just everything.

 

Regular, unless your running a Turbo Seca, then you need Premium. No need for higher octane, it says so in the manual.

 

My wifes family own and operate a non-ethanol gas station, and they say 99% of bikers buy premium. This is my first bike and its not on road yet so that was a question of mine also. I'm probably going with manbot's advice but never ethanol.

 

So the next question, do to the ethonol in fuel is it wise to use a ethonol removing addative if only ethonol fuel is available? ???

 

Octane can be confusing. If you have a high compression motor (over 9.5:1) you need to run higher octane because it will slow and stabilize the burn. That is why so many high output motors run high octane, the higher compression will cause a lower octane fuel to pre-detonate because (believe it or not) lower octane means the fuel will ignite more easily, burn hotter, and less uniformly.

If you are riding your XJ at typical elevation, say less than 5000 feet, then 87, 89, or 91 is fine. I usually run either 89 or 91 mostly because the bike seems to like it better than 87 (get's better mpg & starts easier). If you are riding above 5000 feet you need to run 87, or lower if possible.

Do stay away from EtOH. It doesn't provide the same amount of energy (ie worse MPG), it gums up your fuel system, can screw up rubber, and should never be allowed to sit for more than a week in your tank/carbs etc. Yes I would use an ethanol remedy if you don't have a EtOH free station near you.

 

To my knowledge the only need of octane is to prevent compression ignition. The Maxim's are not high compression and therefor 91 + octane has no benefit. On the other hand it seems most available non-ethonal fuel is the high octane and is just fine. I can only find non-ethonal 87 octane on the coast where it is used in marine outboards. I pick some up when I can as it's less expensive.

Ethonal fuel .... use it but don't let it sit. Run it through and clear it with non-ethonal and you should be okay.

 

http://www.telegraph.co.uk/motoring/cla ... bikes.html

I cant remember how to add a link, but the site above does some explaining of the woes of ethanol. In short, it destroys brass, copper, rubber and plastic. If you must use it, probably should find a station with lowest e content as some states are using 15 % instead of 10% and newer vehicles are being rated for as high as %20. Not good for us and our old bikes. Well, that's my 2 cents for what its worth.

 

Just to add about the evil corn+gas BS

Just got through making a 2700 mile round trip to the East coast in a rental. It was a new Chevy Impala that was 'flex-fuel' capable-meaning it can run on E-85 which is 85% EtOH and 15% Gas. It's cheaper than unleaded so after finally finding an E85 station we filled up with it. NOT A GOOD IDEA. Gas mileage dropped by almost 20%, and since the E85 was only 10% cheaper than unleaded we dropped our MP(dollar) by 10%!!

As an aside the Impala was a surprisingly good car. It was a pretty big car with a 'direct injection' V6 and we averaged 32mpg (hwy w/unleaded ). If we had been driving 65mph instead of 75mph it would have been closer to 38mpg. Pretty impressive for a full size sedan with all the bells & whistles.

Back to XJ's and octane. Keep in mind that it all depends on your compression ratio & atmospheric burn conditions. At sea level, most XJ's compression numbers put the 'ideal' octane rating at 89.5, but you can use any octane that is within 2.5% of that number without any issues. So unless your riding the highest compression XJ (stock but not turbo) at sea level, you can run 87. It seems like 89 is a better fit though for most.

 

I feel I must weigh in...

My SECA 750 asks for 91 on the side cover, but my old maxim 650 funnily enough asked for 87 (and I'd run 87 in it). If i had my time back I would never have run 87 and stuck with 91+ from day one.

My mixture screws had to be way out (4+ turns) to get a hint of brown with 87 and i'd always wonder why there was some fouling when i filled up with the good stuff... With my seca (and the same carb bodies i might add), i'm getting nice brown plugs with 91 octane, at the prescribed ~2.25 turns on the idle... With the ethanol BS going on just spend the few extra cents a liter/gallon and never go back to regular pump gas

 

My 700 says 91 octane leaded. I usually try to put ethanol free in or i go premium

 

Here in Wyoming "regular" is typically 85 octane and "midgrade" is 87. I found going from regular to mid jumped my mileage from 38 to 41 mpg. Next fill up I think I will try one of the two places in town that are ethanol free and see how the bike likes that stuff.

 

Also, when looking at Octane ratings, realize that there are different ways in which it is measured. There's RON and MON which can have as much as an 8-10 point difference. Much of the world (including Japan) uses RON, while America, Canada, and some others use AKI which is an average between RON and MON, (R+M)/2 that you see on pumps. So your manual or side cover could have a higher "number" but check your units...

 

i run whatever i can get with no ethanol in it. around here it's 91 octane

 

The only gas I run is Shell 91 V-Power. Only for the fact there's no corn in it.

*** Finding pure-gas.org yields the following:

Ontario: Shell V-Power 91; Costco 91; Canadian Tire 91; Esso 91; Ultramar 91 are all pure.

Good to know it's not just shell, but I like the additives in Shell gas.

 

i get premium for all street bikes (91-93 non ethanol), also tell all my customers to just spring for premium it aint much more compared to the millage your getting opposed to a truck (or whatever you drive) no shell though, had bad gas from them twice

 

For those who are worries about their bikes being lean(not me personally) would you recommend its best for them to run a higher octane?

 

Hate to bring this back after a month but I'm at sea level and I have a XJ700 Maxim X which has a 11.2:1 compression ratio, is 91 octane going to even be enough? Will I have to run octane boosters?

 

There should be info on the required octane on the inside of the left side- panel. Also be aware that the number listed won't match what is listed on the pump. The US standard changed in the late 80's (IIRC). http://en.wikipedia.org/wiki/Octane_rating The ratings on motorcycles sold in the US used to be given in MON prior to the change to AKI.

You probably won't even need 91.

 

i have run regular 87 oct. with ethanol mostly, has taken me from wisconsin to the cali coast and back, and i dont think its the end of the world to run ethanol as long as you're going to burn through it quick.

i obviously fill up with ethanol free gas as much as i can, but sometimes its just not pratcical/possible.

I will though make sure to put in ethanol free(preminum if need be) when i know i wont be getting too many miles on it for a longer period of time, especially winter with also adding stabil.

 

Actually, isn't ethanol something like 110-120 octane. I always assumed that premium gas was diluted with that "Up to 10%" ethanol in order to boost it from 87 to 93. At least, thats how I'd do it if I was a fuel company.

Also keep in mind that higher octane has less joules of energy per gallon than lower octane fuel. If I remember correctly, diesel fuel is something like 35 octane but contains twice the energy per gallon as regular gasoline.

Oh and as stated octane is a fuel's resistance to burning; higher octane fuels are harder to ignite. So ideally you should run the lowest octane possible before your engine starts to predetonate. This would give you the best milage and most power.

 

I'm at 20' above sea level in CT & also have a Maxim-X. I use 87 octane in it. I tried using 89 octane and premium with no difference in any way that I could see.

Thanks to the brilliance of federal law and the all knowing EPA, all the gas in CT has ethanol in it. Used to be you could get av-gas and gas at boat docks that was ethanol free but no more. The BTUs of gasoline with ethanol is much less than pure gas and it's not the same as it used to be performance wise and gas mileage wise. You will get less MPG and have to use more fuel to go the same distance as before.

A friend I play music with owns a marina and I asked what he suggests to add to gas to deal with the phase separation of water/fuel and he said Star tron enzyme fuel additive seems to work the best. Check out the reviews on Amazon under "Star brite Star Tron Gasoline Additive". I've been using it and I find it seems to help.

Thanks to XHondahack coming over and finding my problem in my carbs, the Maxim-X now gets upper 40's in MPG with my best being 49 MPG when riding rural roads along the coast. I get 44 MPG on the interstate if I ride steady at 60-65 MPH. I also think the 1 oz of star tron in each 6 gallon gas can makes a difference; I get to Boston most every week and fill four 6 gallon gas cans as well as the car because gas is 40 cents cheaper per gallon in Boston. I fill my bike tanks from that gas & rarely need to gas up in CT. I keep the star tron in the car & add it to the cans when I fill them. I've sampled the gas in these cans and find no fuel/water separation any more.

Hope this helps.

 

My ear's are ringing......

Like KA1J mentioned, no ethanol free gas here in CT. because our .gov has decided what's best for us.

In my particular case, I have always used an additive, like Stabil or Seafoam. Now, during the riding season, I'm using the Star-tron as suggested to combat the effects of ethanol.

Personally, I like to run the highest octane available in the X. Mainly because I've done all my tuning with premium (93 Shell V-power). I have no idea if there's a performance loss or MPG difference by using a lesser grade gas.

On to your original question Joiner. You can run a lower octane, even though it has a 11.2 to 1 compression ratio (has a lot to do with how Yamaha set up the camshaft and ignition timing). And, I wouldn't bother with an octane booster. But, as previously mentioned, you should use a quality additive if it contains ethanol. That helps combat the detrimental effects on our fuel systems that weren't designed for it.

 

Given that MTBE (the chemical that ethanol is a replacement for in gasoline) is responsible for polluting ground water, and making water wells unusable, I'll take the ethanol. Ive used E10 for nearly 20 years with no Ill effects, even when I lived in the high-humidity environment of the great PNW. Some extra care is in order, but it's not the evil-demon-child-of-the-tree-huggers that it's been made out to be.
I still prefer it aged in oak barrels though.

 

Aren't these "Octane Boosters" just 95% Kerosene and 5% injector cleaner ??
.
Does everybody know that the tanker trucks only deliver 87 and 93 grade to the station, and the pump blends these 2 to make the 89??
And - if the price break is 20c per grade, then you're getting ripped off buying the 89 octane. If you blended it yourself, you'd have 90 octane.

 

I use Canadian 87 octane in my 82 XJ750 Maxim. I'm currently in the process of eliminating some popping, however the popping doesn't change with higher grades of gasoline. I figure, might as well tune it to the recommended octane. Oh, and no ethanol in our gasoline here in BC, Canada!

 

since the pumps here say ''up to 10%...." , somebody has to make a decision and pick a number, 1 thru 10.
think maybe this is what they base that number on?
http://www.neo.ne.gov/statshtml/66.html
looks like we get the corn now.

 

Yeah. In Connecticut which is trying to emulate the ultra restrictive concept of California, it says on the pumps it's up to 10% ethanol but when I wrote to the different companies like Shell, Sunoco & Mobil, the answer came back that the gas was mixed at the local dealer to be 10% ethanol and the gasoline trucked in to a central distribution point is 100% gas and the ethanol which is trucked in to the same location is mixed there and sent out to the individual end retailers. so the retailers get 90% gas and 10% ethanol and so does everybody they distribute to.

Don't ask me what I think about the government...

 

Y'all realize 10% ethanol in gasoline isn't new...dontchya?