Author Topic: Changing octane... (Read 8063 times)

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.

B12Teuton · « **Reply #1 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.

Red01 · « **Reply #2 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.

Desolation Angel · « **Reply #3 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!

turbo-bob · « **Reply #4 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!

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............

B12Teuton · « **Reply #5 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.

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.

Desolation Angel · « **Reply #6 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.

PeteSC · « **Reply #7 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.

PaulVS · « **Reply #8 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.

Desolation Angel · « **Reply #9 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.

tacoman · « **Reply #10 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.

PaulVS · « **Reply #11 on:** November 03, 2005, 02:52:00 PM »

Quote from: "Desolation Angel"

There's a few cents difference in price, you know.

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. ;)

B12Teuton · « **Reply #12 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

Desolation Angel · « **Reply #13 on:** November 03, 2005, 03:10:06 PM »

Mmmmm, martinis and my Bandit...add a babe and I'd be set!

PaulVS · « **Reply #14 on:** November 03, 2005, 03:25:09 PM »

Quote from: "B12Teuton"

Hopefully not before riding

No. During riding.

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.