Bandit Alley

GENERAL MOTORCYCLE FORUMS => GENERAL MOTORCYCLE => Topic started by: Desolation Angel on October 04, 2005, 03:30:08 PM

Title: Changing octane...
Post by: Desolation Angel on October 04, 2005, 03:30:08 PM
...from 93 (might actually be 94 ??) to 87 has caused some minor odd side-effects.  Has this happened to you?  I have an '01 1200.  For a year I ran premium in it.  Just seemed like the right thing to do.  We had a big octane discussion here recently and I decided I only needed regular grade gas.  My last tuneup was done while I was running premium.  So...

Now I think I'm hearing valve chatter as I ride and the bike is acting funky prior to warming up.  Choke doesn't seem to do much any more.  On premium I would close the choke fully, start the bike, which would idle fast, then I could open the choke to about halfway and it would idle normal as it warmed up.  Now not much happens with choke in any position and the bike dies easily until it's warm.  Seems to chug a bit at first and makes more noise than I remember (mechanical-rattley engine noises).

Should it have been tuned while running regular or is it telling me it doesn't like 87 octane?  Same gas station always, by the way.

Off the Bandit for a second, similar side-effects are occuring with my '82 GS450TX.  Hard to start, doesn't idle right, makes funky engine noises.

I figure for whatever reason the girls are telling me they want a higher priced dinner...not fast food.  I'm gonna try medium grade in both next time (89 octane I think) and see how they act.
Title: Changing octane...
Post by: B12Teuton on October 04, 2005, 04:27:56 PM
Due to lack of gas, there has been rumors of poor quality imported gasoline.  Not sure if this has something to do with it.

I always ran 89.
Title: Changing octane...
Post by: Red01 on October 04, 2005, 07:11:02 PM
Go ahead and try the midgrade. Some people's bikes do seem to need more than regular, Manny's not the only one I've read of.

Can't imagine anything you'd do in a Bandit tune-up any differently for octane since it's just fresh plugs, filter & oil change - and maybe a valve adjustment.
Title: Changing octane...
Post by: Desolation Angel on October 04, 2005, 07:57:14 PM
Well, I wasn't sure about that.  They tinker with my carbs I figured and maybe different fuel requires different adjustments?.  I just walk in and say it needs a tune up and call me when it's done! :grin:
Title: Changing octane...
Post by: turbo-bob on October 05, 2005, 01:05:06 AM
Quote from: "Desolation Angel"
Well, I wasn't sure about that.  They tinker with my carbs I figured and maybe different fuel requires different adjustments?.  I just walk in and say it needs a tune up and call me when it's done! :grin:


Fuel octane would not have caused the symtoms you discribed.

If those knuckle head messed with your carbs.......that would.

Go back - raise hell - tell em it ran better before they touched it !

WTF............
Title: Changing octane...
Post by: B12Teuton on October 05, 2005, 08:44:58 AM
Quote from: "Red01"
Can't imagine anything you'd do in a Bandit tune-up any differently for octane since it's just fresh plugs, filter & oil change - and maybe a valve adjustment.


If it got a new air filter and the air is cooler now, it could be running a bit leaner.  I doubt starting problems have anything to do with octane.  If anything it should start easier with lower octane.

Even when my B12 was stock (before jetting), I never seemed to need full choke.  1/2-3/4 choke and it fired... let it run for a few seconds till the oil circulated and then got under way.  I was off and riding with the choke off in under 30 seconds.   :btw: I still have my friends '03 B12 that I've been riding every day.  It's box stock and is exactly the same as my '01 was.
Title: Changing octane...
Post by: Desolation Angel on November 03, 2005, 10:59:18 AM
Not meaning to reanimate the dead (thread), but I just happened to be reading through my owner's manual and noticed Suzuki doesn't actually make a fuel grade recommendation.  They use wording to the effect of, "Use a fuel with an octane rating of at least 87 by the the (R+M)/2 method."

Use an octane of AT LEAST 87.  That's not really telling us which one the manufacturer recommends, does it?  Sort of makes it sound like they're saying, "OK, cheap@ss, you gotta at least put in 87, you dig?"  I would infer from that wimpy wording that higher octane would be the preferred way to go.

I know we all have octane opinions, but I'm just going for the moment on what the manual seems to hint at, but doesn't have the b@lls to specifically state.  Maybe they were scared to recommend a more expensive grade of fuel?

Just an observation.  Seemed odd they don't state a specific grade like my Saab and Audi manuals do.
Title: Changing octane...
Post by: PeteSC on November 03, 2005, 11:15:34 AM
Suzuki doesn't say you CAN'T change your oil and filter every 50 miles, or throw your tires out after 100 miles, either. :stickpoke:
Title: Changing octane...
Post by: PaulVS on November 03, 2005, 11:17:17 AM
I almost never use "B-grade" fuels.  I try to stick with Shell or Amoco unless I don't have those options.  There IS a difference between brands - but it's usually the additives the company uses more than the 'raw fuel' itself.

Also... a lot of other factors like how long the gas stays in the tanks at the gas station and what condition those tanks are in can come into play.

Not to re-hash the octane issue... but people do think 'more is better' about it... and it's not true.  In fact, the lower the octane, the faster burning it is.  So you should use the lowest octane that doesn't result in detonation/ping/knock.  Most people with B12's have found 87 works fine.  I'm convinced that my bike runs better on 87 than 93, and I really can't tell any difference between 87 & 89.
Title: Changing octane...
Post by: Desolation Angel on November 03, 2005, 11:29:56 AM
That brings to the forefront the debate on name brand vs. off brand fuels.  Am I served better by using fuel from ExxonMobil, rather than fuel from my local Tom Thumb grocery store?  I wonder.  Hmmmmm.

There's a few cents difference in price, you know. :grin:
Title: fuel
Post by: tacoman on November 03, 2005, 01:42:34 PM
There are only so many refineries so where you buy the gas isn't as big of issue.  I think couple things could be happening.  Refineries re-blend fuel for different seasons.  You may have ingested some "winter" fuel and the Bandit isn't happy.  You could have gone to a station that isn't large volume and the fuel has gone slightly stale.  The station may have been recently filled and some water in the tanks got stirred up.  Also, with the recent shortages, I wonder about the quality right now.  A station by my house had cheap fuel prices and when I looked at the octane, it was rated at 86.  My car ran like crap.  I usually go with the mid grade 89 and use a station by my house that is always busy so their fuel is fresh (the 86 octane is no longer offered, they must have gotten too many complaints.
Title: Changing octane...
Post by: PaulVS on November 03, 2005, 02:52:00 PM
Quote from: "Desolation Angel"
There's a few cents difference in price, you know. :grin:


I figure if you drive 6000 miles a year on your Bandit, you'll use about 150 gallons of gas.  (Figuring @ 40mpg)

If you pay an extra .05-.10 cents per gallon for the name brand stuff it will cost you about $8-16 more a year.

I spend that on a Martini or three every Friday night.  ;)
Title: Changing octane...
Post by: B12Teuton on November 03, 2005, 03:01:10 PM
Quote from: "PaulVS"

I spend that on a Martini or three every Friday night.  ;)


Hopefully not before riding :stickpoke:
Title: Changing octane...
Post by: Desolation Angel on November 03, 2005, 03:10:06 PM
Mmmmm, martinis and my Bandit...add a babe and I'd be set! :grin:
Title: Changing octane...
Post by: PaulVS on November 03, 2005, 03:25:09 PM
Quote from: "B12Teuton"
Hopefully not before riding :stickpoke:


No.  During riding.   :wink:

Just kidding.  Friday night the missus & I do the "what a friggin' week!  Let's go spend too much at an expensive restaurant" thing.  If we do take the bike... we abstain.
Title: Changing octane...
Post by: B12Teuton on November 03, 2005, 03:26:05 PM
I wonder how the B12 engine would run on Martinis?
Vodka or Gin?

I'm a Bombay Sapphire man.
Title: Changing octane...
Post by: Desolation Angel on November 03, 2005, 03:39:32 PM
Quote from: "B12Teuton"
I wonder how the B12 engine would run on Martinis?
Vodka or Gin?

I'm a Bombay Sapphire man.


Finlandia for me, please.
Title: Changing octane...
Post by: rocketman1 on November 25, 2005, 09:06:15 PM
In NZ we have 96 and 91 Octane unleaded my bike goes just fine on the 91 Octane, full choke of the first 3 or 4 seconds then ease off for about 10 seconds and Im away no probs. daytime temp about 18 Degrees Centigrade
Title: Changing octane...
Post by: B6mick on November 26, 2005, 07:42:15 AM
Ok, I do just luv, the mighty fuel debate. :lol:  :lol:
The nuckle heads tinkering with ya carbs, find that hard to believe, but could happen. But being a wrench myself, I ask this. If its running fine why would anyone pull the carbs to tinker. Drain the bowls yes, but unless the owner asks for the carbs to be tinkered with, no way basic tune up never, if the bike ran real bad, when it came in, yes but otherwise, no way the workshop would go broke in a week.
My suggestion is, start using premium grade fuel again, after 2 to 3 tanks you will have the answer. Your bike likes premium, or someone been stuffing with your carbs and did a shocking job. :grin:
Yes the other thing is to watch out for winter grade fuels, can some times play havoc, I dont know about over there, but here they are sneeking into the fuel, ethanol again, Aussies, be carefull BP seems to be the main offender. Well its not actually BP its some of the operators. Bp's premium plants is off line again, for reasons unknown. Most Bp stations have signs up on all premium pumps, out of order. But some seem to have premium, but I am assured it is not BP. Have had a few bikes in over the last few weeks running off song, the 1 st few had us at the shop stumped.
Common denominator, BP premium fuel, drain tank and carbs, fresh fuel from another supplier. :motorsmile:  yep no problem, on song and running fine. Just to prove the point we now have 5 batches of fuel being tested by the CSIRO.
Title: Changing octane...
Post by: aussiebandit on November 26, 2005, 08:14:55 AM
Ok so that's Shell Optimax, BP, that Woolworths crap that I won't put in the B12 or the M750 (unless there's no real choice).

That leaves Mobil, Caltex and not a lot else.
Title: Changing octane...
Post by: PaulVS on November 26, 2005, 12:50:49 PM
Keep in mind the U.S. octane rating method is different from Europe, Australia, and New Zealand.  If I'm not mistaken, 91 octane there is the equivalent of around 89 octane U.S.

(Someone feel free to correct me if I'm wrong.)
Title: Changing octane...
Post by: ergopower on November 26, 2005, 08:32:24 PM
The higher the octane rating, the higher temperature/pressure is required for combustion. That's good in a high-compression engine, it prevents the mixture from detonating instead of burning. But in a lower-compression engine, it can mean incomplete combustion because the flame front is slower at lower temperature/pressure, potentially too slow. In that case, unburnt residue gradually builds up in the cylinder, and this creates hot spots. It's generally not noticeable if you continue to use high octane gas; but if you then switch to a lower octane rating, the hot spots can cause detonation/knocking/pinging/whatever you want to call it. So using higher than necessary octane for long enough can mean you are stuck using it. Have you tried going back to high-test yet?

Brian
Title: Changing octane...
Post by: pmackie on November 27, 2005, 01:03:08 AM
Some additional comments, just to add to the complexity...

Gasoline is NOT a static product. Due to many factors, including gov't legislation and regional historical conditions, gasoline formulations need to change seasonally, sometimes more often.

One of the common things that changes is it's vapour pressure, often measured using the Reed Vapour Pressure method (RVP). The basics are that the light ends of the fuel (those parts that vapourize easily at ambient temp) are reduced in the summer and increased in the winter, usually in several steps. You need more light ends in the winter to allow the fuel to vapourize easily at lower ambient temperatures to allow easier starting. If you don't have enough percentage of the fuel that will readily vapourize, you cannot easily start the engine.

In the summer these light ends are reduced for a couple of reasons.
1. Too many light ends vapourizing can lead to vapour lock in some fuel lines/fuel pumps etc.
2. Excess light ends entering the atmosphere lead to an increase in ground level ozone, or smog.

Anyway, a common isssue every fall is that as the temperature drops, the current "summer" RVP gas in the system may lead to harder starting, especially in carburated engines. As the higher RVP gasoline makes its way through the whole system, the effect goes away.

In the case of October/November deliveries in Texas, there are many refineries still down and/or just coming back on line. It is likely there is still lower RVP gasoline coming out of the refineries in your area.

I expect the effect you are seeing has more to do with the supply/invertory logistics in your area and less to do with octane.
Title: Changing octane...
Post by: jared1970 on November 29, 2005, 03:07:05 PM
Quote from: "B12Teuton"
Due to lack of gas, there has been rumors of poor quality imported gasoline.  Not sure if this has something to do with it.

I always ran 89.


I think there's merit to this rumor. Immediately following Katrina, I noticed my car would ping no matter what octane I ran in it. I normally run 89 octane in all my vehicles, as its state subsidized here in Iowa, making it about $.10/ gallon cheaper than 87, and much cheaper than premium.
However, in recent weeks I've noticed this problem has subsided, and I think the poor quality gas problem is starting to phaze out.
You may also want to try buying the same octane gas from several manufacturers. One manufacturers 87 octane is not the same as another's 87. But most importantly, check your owners manual to see what octane fuel Suzuki recommends you use in your Bandit.
Title: Changing octane...
Post by: Wooddog on January 29, 2006, 06:51:34 PM
My Mother has managed convenience stores for 20 years and she tells me just because you pay for the 91 octane, does not mean you are getting 91 octane.  She says when the fuel truck fills up the 87 octane tank and needs to empty the rest of the truck,  he puts the 87 octane in the 91 tank, and that seems to happen all the time. So who knows what octane you are getting. I would say buy the cheap gas and if your bike does not run well on it then go to wal mart or auto zone and buy a bottle of octane booster and add it to your gas.
Title: Changing octane...
Post by: Kickstart on January 29, 2006, 08:35:02 PM
Quote from: "PaulVS"
Keep in mind the U.S. octane rating method is different from Europe, Australia, and New Zealand.  If I'm not mistaken, 91 octane there is the equivalent of around 89 octane U.S.

(Someone feel free to correct me if I'm wrong.)


Europe (and Aus I think) uses the Research Octane Number (RON). The other common measured octane rating is the Pump Octane Number (PON) which as a rule of thumb gives a rating about 10 points lower for the same fuel. The USA uses the Motor Octane Number (MON) figure which is the average of the RON and PON, so as a rule of thumb about 5 points lower than the European figure. Standard unleaded fuel in Europe is 95 RON (nothing lower is available in the UK that I know of) while higher octane 97 / 98 RON is also available.

All the best

Keith
Title: Re: Changing octane...
Post by: Slider on January 29, 2006, 09:57:04 PM
Quote from: "Desolation Angel"
...from 93 (might actually be 94 ??) to 87 has caused some minor odd side-effects.  Has this happened to you?  I have an '01 1200.  For a year I ran premium in it.  Just seemed like the right thing to do.  We had a big octane discussion here recently and I decided I only needed regular grade gas.  My last tuneup was done while I was running premium.  So...

Now I think I'm hearing valve chatter as I ride and the bike is acting funky prior to warming up.  Choke doesn't seem to do much any more.  On premium I would close the choke fully, start the bike, which would idle fast, then I could open the choke to about halfway and it would idle normal as it warmed up.  Now not much happens with choke in any position and the bike dies easily until it's warm.  Seems to chug a bit at first and makes more noise than I remember (mechanical-rattley engine noises).

Should it have been tuned while running regular or is it telling me it doesn't like 87 octane?  Same gas station always, by the way.

Off the Bandit for a second, similar side-effects are occuring with my '82 GS450TX.  Hard to start, doesn't idle right, makes funky engine noises.



The choke quote above makes no sense to me. "Not much happens in any position", sounds stange. I wonder if it is a stuck choke cable.

 Mine hung up partly open on me -never to move much again, I might add. The mechanic thought the teflon? lining had wadded up and jamed.
A new choke cable worked. The other noises are ???

Up here in Beaver Land the regular gas works like a charm in my B1200. All crabbiness that the bike had prevously, turned out to be the disgustingly lean jetting legislated by the Gov't. Low speed jet reset and carb needles up a notch solved this with no detectable loss in mpg.
 :grin:
Title: Changing octane...
Post by: Red01 on January 30, 2006, 12:18:45 AM
Quote from: "Kickstart"
Europe (and Aus I think) uses the Research Octane Number (RON). The other common measured octane rating is the Pump Octane Number (PON) which as a rule of thumb gives a rating about 10 points lower for the same fuel. The USA uses the Motor Octane Number (MON) figure which is the average of the RON and PON, so as a rule of thumb about 5 points lower than the European figure. Standard unleaded fuel in Europe is 95 RON (nothing lower is available in the UK that I know of) while higher octane 97 / 98 RON is also available.


You're close Kieth. RON is what's used in many countries, but what you've got MON & PON crossed.

From Wikipedia: (http://en.wikipedia.org/wiki/Octane_rating)

Quote
The most common type of octane rating worldwide is the Research Octane Number (RON). RON is determined by running the fuel through a specific test engine with a variable compression ratio under controlled conditions, and comparing these results with those for mixtures of isooctane and n-heptane.

There is another type of octane rating, called Motor Octane Number (MON), which is a better measure of how the fuel behaves when under load. MON testing uses a similar test engine to that used in RON testing, but with a preheated fuel mixture, a higher engine speed, and variable ignition timing to further stress the fuel's knock resistance. Depending on the composition of the fuel, the MON of a modern gasoline will be about 8 to 10 points lower than the RON. Normally fuel specifications require both a minimum RON and a minimum MON.

In most countries (including all of Europe and Australia) the "headline" octane that would be shown on the pump is the RON, but in the United States and some other countries the headline number is the average of the RON and the MON, sometimes called the Anti-Knock Index (AKI), Road Octane Number (RdON), Pump Octane Number (PON), or (R+M)/2. Because of the 10 point difference noted above, this means that the octane in the United States will be about 4 to 5 points lower than the same fuel elsewhere: 87 octane fuel, the "normal" gasoline in the US and Canada, would be 91 in Europe.

It is possible for a fuel to have a RON greater than 100, because isooctane is not the most knock-resistant substance available. Racing fuels, straight ethanol, Avgas and liquified petroleum gas (LPG) typically have octane ratings of 110 or significantly higher.
Title: Changing octane...
Post by: mike on January 30, 2006, 12:44:00 AM
"An engine is like a woman"...
Take her to 5 star restaurants for years,
then try dinner at Bennigan's or Friday's, she's gonna bitch !!    :bigok:
Title: Changing octane...
Post by: Swamp Rat on January 30, 2006, 11:30:08 AM
One other little tidbit. Most of the refineries dump there fuel to a common pipe line. They denote how much fuel they added to the system. When the tanker trucks fill from the loading stations they denote how much they took away and of what grade. Checks and balances.
  Many different refineries fill into this same system. The difference ends up only being the additives package. Kind of how you put a bottle of octane booster or injector clraner in your car is how the additives are added to the common gasoline. If you were to drive to one of these filling ports you would see several manufacturers additive tanks and only a few gasoline tanks. So when someone says it's all the same stuff, other than octane and additives, it truly is.
Title: Changing octane...
Post by: Red Bandit on January 30, 2006, 02:41:56 PM
you say that the choke now has little or no effect. That is probably not gas, the choke is manual and dramaticly effects the fuel air mixture. I would suspect the carb work was the problem, not the gas.
Title: Changing octane...
Post by: rider123 on January 30, 2006, 08:21:03 PM
My brand new 2005 Bandit 1200S pings a little on just 87, it also runs a little rougher. When the tank was half full of 87 I put a half tank of 91 which brought the effective octane level probably to around 89 and it ran immediately better and smoother with a bit more snappyness. I know it's not good to use 2 different brands so I'm going to try a tankfull of premium at 91 and a tankfull of 89 which it probably needs. I was losing power and pingin when full hot with 87. My GS750EF was the same didn't like 87 but 89 worked well, anything over that there was no difference but in my wallet. Stuck to 89 with no probs. I'm also only 500 ft above sea level so it probably needs that extra 2 points on the octane scale.
Title: Changing octane...
Post by: Kickstart on January 31, 2006, 09:04:17 PM
Quote from: "Red01"
You're close Kieth. RON is what's used in many countries, but what you've got MON & PON crossed.


 :duh: .Worst of it is I know that and just wrote it down wrong. Definate dumb moment.

All the best

Keith