Unleaded fuel

[mckdavid]

Hi all,

I'm new to this forum and I'm well impressed with it, and this is my first post, although looking at the machine in the garage, I somehow doubt it'll be the last.
Anyway to the chase I've just bought an old GSX 1100 ES to restore, cracking bike, I had one a long time ago with fond memories, so when I spotted this one, logic went out the window and I'd bought it before really thinking it through. So there we have it, I'm a bike owner again, happy days, never liked logic that much anyway..........it's all too easy to talk yourself out of things that you enjoy.

Then reality dawns, it's been a while since I've had a bike, so I've a question for you technical types. When I owned my original there was still leaded petrol around, that's no longer the case, well not here in Europe at least. Therefore the question is is, can the GSX motor survive the unleaded 98/95 fuel, it's as bulletproof as the hills so I have no real doubts that it will, but are the valve seats up to the extra heat, and what adjustments to the carburation and ignition are required.

I've ordered the Haynes manual, but I'm just too impatient to wait for it to arrive, so I thought I'd use this opportunity to join the forum.

Thanks for your assistance, and I'm looking forward to getting the old girl running in fine fettle again, though it might be awhile, time permitting.

Regards
David

 

[marvinsc]

Welcome to the GSR David! I have been hanging around here since April and as far as I know, Everyone Runs Unleaded Gas with no problems. I have noticed that My 850 runs best on the Mid Grade 89 Octane.

 

[Tarbash 27]

I RUN 93 OCTANE IN MY 79 GS750. MY BIKE RUNS BETTER THE HIGHER THE OCTANE. I RUN 93 IN EVERYTHING, MOTORCYCLE, TRUCK, MOPED, LAWNMOWER. ONCE AND I WHILE I GO TO THIS BP STATION A FEW MILES AWAY THAT HAS 110 LEADED OCTANE. BIKE RUNS WITH SO MUCH POWER AND SO SMOOTH. I WOULD LIKE TO PUT IT IN ALL THE TIME BUT ITS $6.00 A GALLON WHEREAS 93 UNLEADED IS ABOUT $2.87 A GALLON. THERE SHOULD BE NO PROBLEM RUNNING UNLEADED.

 

[fastpakr]

You do realize that there is absolutely no more energy content in high octane fuel than standard 87, correct? If the engine pings with a given rating it makes sense to increase as necessary (as well as determine the cause, if you're having to use fuel above the official requirement). It is categorically NOT a power adder, though. The reason high octane fuels are typically required with more performance oriented engines is because of dynamic compression.

 

[focus frenzy]

hello David and welcome to the forums.
all GS's come from the factory with hardened valve seats for use with unleaded fuel.

 

[Boondocks]

The Suzuki factory manual for my 1980 GS1100E (GSX1100E in Europe) recommends 89 octane unleaded only.

There is no benefit or performance to be gained from higher octane with a stock engine that is not pinging (pre-ignition). Using aviation-type gasoline is a waste of money.

The use of leaded gas will created combustion chamber deposits and drastically shorten spark plug life .

 

[Nerobro]

If you see improved power with higher grade fuel, your bike is having other issues. Most likely, it's running to lean and you're actually getting the begining of detonation.

According to my manual, 85-93 ocatne is what's reccomended. ;-) gotta love low compression air cooled motors. As for your ES... Midgrade unleaded is probally just fnie for ya. I wouldn't seccond guess the manual.

 

[Alan Schlosser]

The manual for my 82 1100 shows that you should use 85-95 pump octane using the R+M/2 method or 89 or higher octane rated by the Research method.
I ususally run 87 octane in my bike with no problems. I sometimes treat it to 89 when I'm feeling generous, but I couldn't tell you of any power difference. It's really only going to help with pre detonation.

 

[LW_Icarus]

I stick with mid grade gas for the bike, and avoid older stations that may have contaminated fuel storage. also avoid stations that have just had fuel dropped too as it mixes up any crud on the bottom of their tanks.

my bike runs just fine on 87-89 octane fuel, and thats fine with me, as gas prices are high enough I dont wanna haveta spend the money

 

[toymechanic.]

You do realize that there is absolutely no more energy content in high octane fuel than standard 87, correct? If the engine pings with a given rating it makes sense to increase as necessary (as well as determine the cause, if you're having to use fuel above the official requirement). It is categorically NOT a power adder, though. The reason high octane fuels are typically required with more performance oriented engines is because of dynamic compression.

I'm not trying to start a fight here, but I have used 110 octane in my atv. And have had a lot of people tell me that there is no advantage to running higher octane fuels. You may not be able to tell a difference between 87 and 89, but you put 110 octane in and there is a performance difference. The bike runs noticably different(a stock bike). So you tried 110 octane and didn't notice a difference of how your bike ran with. Or are you just going by what the know it alls say. Because there is a difference when I use it. Regardless of what people say, it is a performance boost and it runs cooler!

 

[Clone]

Well, reading through his first post, you will see that IN EUROPE they rate gasoline with a RON value. So his 95 is about a 90 octane value, 92 is about 87, and 98 would be our supreme or 92/93.

 

[Nerobro]

I'm not trying to start a fight here, but I have used 110 octane in my atv. And have had a lot of people tell me that there is no advantage to running higher octane fuels. You may not be able to tell a difference between 87 and 89, but you put 110 octane in and there is a performance difference. The bike runs noticably different(a stock bike). So you tried 110 octane and didn't notice a difference of how your bike ran with. Or are you just going by what the know it alls say. Because there is a difference when I use it. Regardless of what people say, it is a performance boost and it runs cooler!

Also keep in mind most extremely high octane fuels are frequently oxygennated. And that WILL give you a horsepower benifit.

 

[Tarbash 27]

You do realize that there is absolutely no more energy content in high octane fuel than standard 87, correct? If the engine pings with a given rating it makes sense to increase as necessary (as well as determine the cause, if you're having to use fuel above the official requirement). It is categorically NOT a power adder, though. The reason high octane fuels are typically required with more performance oriented engines is because of dynamic compression.

I'm not trying to start a fight here, but I have used 110 octane in my atv. And have had a lot of people tell me that there is no advantage to running higher octane fuels. You may not be able to tell a difference between 87 and 89, but you put 110 octane in and there is a performance difference. The bike runs noticably different(a stock bike). So you tried 110 octane and didn't notice a difference of how your bike ran with. Or are you just going by what the know it alls say. Because there is a difference when I use it. Regardless of what people say, it is a performance boost and it runs cooler!

I USE 110 ONCE AND I WHILE AND THERE IS A BIG DIFFERENCE IN POWER THAN RUNNING 93. MY BIKE WOULD KEEP PULLING WHEN I REV IT OUT. I HAVE USED 87 OCTANE IN MY BIKE AND IT JUST DOESN'T RUN AS NICE AS 93. THERES NOT MUCH OF A DIFFERENCE BUT CAN STILL TELL. I REALLY CAN COMPLAIN ABOUT GAS PRICES IN BETWEEN 87 AND 93. WHEN IT WOULD COST ME ABOUT $12 TO FILL MY BIKE ON 87, ITS LIKE $13 TO FILL ON 93. I MEAN THERS A DIFFERENCE WHEN IT COST $30 TO FILL IT ON 110.

 

[fastpakr]

Tarbash, if that really is the case then you're band-aiding a legitimate problem that needs to be fixed.

 

[RobGS850L]

I've actually done the high octane performance test on stock engines. A stock engine actually will lose power because the burn rate of the 110 octane is not the same as the low lead. The engine runs best when you burn all of the fuel and not a portion as is the case with higher octane fuel. High compression engines create fast burn rates because of the friction created by the higher compression. That's the reason for high octane, to fight faster burn rates. Most racing type fuels are cleaner and don't have the additives that the lower lead types do. Therefore you end up with cleaner plugs and less fouling. At max spark advance (whatever factory specs may be) you want the engine to be on the edge of pinging. That is where the power is. :wink: If you don't believe me read the hipo horsepower books out there. I did the test years ago and I did go slower with the race gas.

 

[Tarbash 27]

WELL MY BIKE RUNS PERFECTLY FINE. THERE'S NO PROBLEM WITH IT. MY FRIEND PUT 110 IN HIS HONDA 450 AND FELT AN INCREASE IN POWER. MY MOMS BOYFRIEND PUT IT IN HIS 2004 HARLEY AND FELT A DIFFERENCE. IM NOT GOING TO TELL ANYBODY WHO'S RIGHT AND WHO'S WRONG. IM JUST SAYING IT WORKS FOR ME.

 

[Pete Logan]

Well, reading through his first post, you will see that IN EUROPE they rate gasoline with a RON value. So his 95 is about a 90 octane value, 92 is about 87, and 98 would be our supreme or 92/93.

This comes up from time to time. You are quite correct, the octane ratings are measured differently in US and Europe.

The simple way to think about it is Regular is Regular, and Premium is Premium.

There's about 5 points difference as a rule of thumb, so our 95 is your 90, and our 98 is your 93-ish.

But the thing to remember is that AFAIK it's the same gas, regardless of displayed octane rating.

Just in passing, I run European 98 (Premium) in my '82 750E and it does not like the Regular

But I also run the Premium with Lead Substitute through there quite happily.

The motor's good for Unleaded, as has been said.

 

[mckdavid]

All,

Well, what can I say, thanks for all the replies, I certainly didn't expect this many responses. To summarise, there is basically no problem with unleaded fuel for this engine, as the inlet and exhaust already have hardened seats in the head and was designed with this in mind if the official manual recommends unleaded. Good news, so we can run without major reworks or modifications.
Reference the fuel grades, it seems there is a lot of debate on which is the best fuel rating, I can't assist on this one, except to say that as long as the engine is running smoothly without detonation, the spark plugs being a nice brown colour, and the mpg being about right, then the fuel your are using is pretty much spot on, and there is no point paying for a higher grade than necessary, you probably aren't gaining much advantage in practical terms.

As Clone stated, here in Europe we use a different classification, but in essence it's all the same stuff. I don't have a conversion table to hand so can't compare the US rating system with ours, but 98 is the highest rating available here "off the shelf", I'm sure there are more exotic brews available but from specialists, and with the price of fuel here, 98 is more than enough already.....

Thanks again.

regards
David

 

[toymechanic.]

I have never been in Europe, so I can not say what is better there. My experience with Higher actane fuels, the bike runs stronger, faster and responds better than lower octane fuels. And the higher octane fuel also give a higher top speed. The next time your buddy keeps out running you by a small amount. Go put in some high octane fuel and race him again. You'll beat him. I had a '97 Polaris Sportsman 500, a friend had a '02 Yamaha Warrior he would also beat me by a small margin, then secretively a got the racing fuel and he couldn't figure out how I started beating him all the sudden. But he could smell it in my exhaust so I was busted. It does make a difference and there was nothing wrong with my atv. Had the same results back in the '80s with dirt bikes. We were also told by someone"not to use it all the time and not to use it full strength". We didn't use it all the time, but we did use it at full strength!

 

[duaneage]

The US environmental protection agency required the bikes to state that only unleaded gas should be used. The truth is leaded can be used because there is no catalytic converter on these bikes.

Lead clogs the screens in the converters and they fail in short order. Lead was used to lubricate and protect the exhaust valves. In 1972 almost all companies ( including Suzuki) went with more expensive hardened valves and seats, negating the need for leaded gas.

Engines that have a steady diet of leaded gas will have white coating at the exhaust pipes. I have not seen white exhaust ports on an engine in 18 years. (sigh)