What grade of fuel for a GS?

[Anonymous]

What grade of fuel would best suit a 650L?


And What type of oil?

[Planecrazy]

I always put in the highest octane fuel available (premium). The reality is that it probably makes little difference, but I figure why take the chance when the difference in price is a matter of several cents per gallon?

I'm a big fan of Mobil One Synthetic oil. I've used it for years and think it's worth the extra cost.

Regards,
Steve 8)

[Anonymous]

Cheap 87 octane is what I've used on all my GS bikes since 1986. No point in wasting your money on premium. If your bike is tuned properly and your engine is stock, it should run perfectly on cheap gas, regardless of brand.

We've gone around and around on this issue, with some heated nonpolitical debates on this. So, here we go again. I'm saying my peace on the basis of having been a GS owner of four 850's and one 1100GK, with 210,000 miles on them altogether.

If one has to run a GS on premium in order for it to run correctly, one should get the bike fixed. There's something wrong with it. Premium treats the symptoms, not the disease.

As for oil, another subject of heated debate. I use 10W40 motorcycle specific Quaker State oil I get at Walmart, year round. I stick with the manufacturer's recommendation. Plain auto oil seems to work fine for many, however, and it should be fine as long as you change it regularly and often.

So, here we go again. I've voiced my opinion, based on long years of GS ownership. A GS650 is a mildly tuned engine like the 850 and 1100 shafties, so don't waste your money on premium.

Nick

[saaz]

I tend to agree with Nick. A properly tuned engine will not run better on a higher grade of fuel, in fact it may loose power due to the slower burn characteristics that control detonation. Cheap fuels may not have good additive packages or may be contaminated, I have found that some brands in the same octane rating do perform differently (this is in Australia)

AS for oil, what is the best length for a piece of string? In normal conditions use the recommended grade and change it at least as often as recommended. In hotter conditions, hard use etc I have found that better oils or heavier grade oils do last longer in terms of gearbox performance - cheaper oils are noticeably degraded more quickly and can feel different in terms of clutch performance. There is no right answer here. I run a modified engine, it generates a lot more heat than standard, so oil cooling is my main worry, than type of oil and when I will change it.

[Hoomgar]

I have to go with Steve on this one as far as the gas to use. There is no point in putting low octane fuels in anything that burns gas as it is only a few cents less per gallon and the savings are just not there. I personally have tested the theory over my 22+ years of burning gas in many engines not just bikes and my experiences are consistent without an exception. Higher octane fuels give me a noticable better gas milage than the lower actane fuels. In lots of cases more than a couple miles per gallon so when that one thing alone holds true it is actually cheaper to use the higher (cleaner) octane fuel in your engine. Why pay more money for a low grade? Doesn't make sense. My current GS is just as stated. It will run fine on any gas you put in it but runs noticable better on the higher octane fuels and I swear it runs cooler but can't really prove that. If and when you ever tear any engine down you can always tell what grade of gas was used in it by the amount of crud left behind. Lower octane fuels have way more dirts in them than the higher grades and you have to run that through your engine.

Please note that just as Nick stated, this is my experiences in my life and may not hold true for someone else. But it is what I have found to be true in all my engines.

So my bottom line answer would be.. go with the higher octane for sure in anything that burns gas. Even your lawn mower. The lower octane fuels can actually cost you more money to run more dirt through your engine and have less performance than you can have on higher grades. This is why racing fuels are cleaner and with a higher octane Most bikes now a days will recommend higher octane fuels as well and my mechanic also suggests running the highest octane pump fuels available for the life of your engine.

Hope that helps.

[first timer]

i run 89, if your engine is not heavily modified then use the cheap stuff.

ryan

[earlfor]

Well. yes and no. Many GS's probably run fine on regular 87 octane gas. A lot depends on the ambient air temperature, the loads put on the engine, and the resultant operating temp. Factory service manuals specify an octane minimum. It may or may not be 87. The factory specs a minimum of 89 octane for my 1150. When the air temperatures are 90F or less, 89 is fine. When temps get near the 100F range, engine operating temp also increases and I have to use 93 octane if I want to eliminate preignition under certain throttle applications. There is no time when I can use 87 without getting preignition. Since I am the only one I trust to put a wrench to the bike I know there is nothing out of spec in the set-up and tuning of my 1150. The bike runs like a turbo Ferrari. :-) Smooooth!

Earl

[quote="Nick Diaz"]
If one has to run a GS on premium in order for it to run correctly, one should get the bike fixed. There's something wrong with it. Premium treats the symptoms, not the disease.

[GNAHT-2]

I am not one who is knowing the best of the octanes level to be putting in a bike. I am however always using the jet fuel which is being very high in the levels of octane on my jetskiis. This is making them go much noticeable faster than the fuels of regular combustionable qualities.

However, this thread is in the bringing up of a new question. Since we are in the conversement about octanes, and I am always in the search for the refineability of my English grammars, what is really being the plural of octane? Is it being "octii"???

Meskito

[AOD]

octanii

[jimcor]

I'm going to agree with Nick on this one. No need to use 93 Octane if your bike will run on 87. Oil...suit yourself, multigrade 10W40 changed often.

[dpep]

Well. yes and no. Many GS's probably run fine on regular 87 octane gas. A lot depends on the ambient air temperature, the loads put on the engine, and the resultant operating temp.

Earl beat me to this point and did a better job than I would have. It's all about the heat and the preignition. Gas price and mileage are considerations but neither of those factors will damage your engine. Preignition will. If you are running in cooler tempratures and not pushing hard your engine should stay cool enough not to ignite a low octane fuel before the spark. Run the same bike hard on a hot day with two up and maybe not. Our air cooled engines make us more vulnerable. If you have pinging, move to the next highest octane.

[Griffin]

I agree that operating conditions and the state of tune of the bike will determine the octane level required.

When riding a GS550 eighteen years ago, 87 octane was fine for driving around town or on the open road. Around the track, running constantly between 8,000 and 10,000 rpm, 93 octane was absolutely required to prevent preignition problems.

My GS700 has never been racing, never spent much time over 6,000 rpm, and has never had anything but 89 octane fuel with no problems at all.

[Anonymous]

87.. 93.. ? i dont know...

i do know that i am glad that Earl posts on this site. he is always straight forward and on the money, no bull sh*t...

if i ever grow up, i want to be just like Earl...
thanks Earl

van

[Hotblack]

I agree with Nick, Earl, dpep, et. al. Personally my bike has never been anywhere near a ping under my ownership, and I always use 87 octane. I am skeptical of any gas mileage increasing by virtue of octane alone, but there may be another variable in the equation. Increased octane, to my knowledge, doesn't mean cleaner gas, either. However I do own a vehicle that needs good gas in order not to ping, and I've gotten a lot of different results from different brands at the same octane rating. The car in question absolutely HATES Hess gas, whereas Amoco gives the best results. There is a whole catalog of brands that are good and bad to varying degrees, but those are the extremes. Again this is personal experience with a quirky old car, but those observations are consistent through my ownership and operation of the vehicle. My 550, by the way, has no problem running on Hess gas even in hot weather at full throttle.

I still find Hoomgars observations interesting, and I my try some experimentation of my own. One thing, you don't always hear preignition if it's light enough, so if you switch to a higher octane and get better mileage, It's quite possible you were experiencing preingnition even if you didn't hear it before. And then again there are many vehicles made today that automatically adjust engine tune to prevent preignition, so switching to higher octane can have effect in that case as well. You may not have pinging, but if your engine isn't remapping everything to accomodate inadequate fuel you're going to get better performance.

[earlfor]

Wow, aw shucks man, (shuffling foot, kinda embarrassed like) :-)
I donno, it kinda scares me when I say something that makes sense. :-)
Thanks

Earl

87.. 93.. ? i dont know...

i do know that i am glad that Earl posts on this site. he is always straight forward and on the money, no bull sh*t...

if i ever grow up, i want to be just like Earl...
thanks Earl

van