For those that advocate using 87 octane in these bikes

[Allie]

Ride More Worry Less. Good advice..........................

 

[jbs80106]

Dunno.

Benefits of living at high altitude maybe? I run 85 in both bikes and both vehicles. Not problems. Occaisionally running higher grade in the SUV.

Downside of living at high alt, I think our prices for 85 are akin to what others pay for 87. Here the only offerings at the petrol station are 85/87/90. 92 is not an option except for 1 station in town that also sells leaded gas still.....

 

[Allie]

Dunno.

Benefits of living at high altitude maybe? I run 85 in both bikes and both vehicles. Not problems. Occaisionally running higher grade in the SUV.

Downside of living at high alt, I think our prices for 85 are akin to what others pay for 87. Here the only offerings at the petrol station are 85/87/90. 92 is not an option except for 1 station in town that also sells leaded gas still.....

Wow. We only get 87/89/93 here. Or is it 92? I think Sunoco has more grades available, plus race gas, but I don't go there.

 

[tkent02]

Yep, it's an elevation thing. 85 runs fine, unless you ride down in the flatland. But that lowland riding is way too boring to even contemplate, it's just not going to happen.
85 is fine.

 

[Allie]

Yep, it's an elevation thing. 85 runs fine, unless you ride down in the flatland. But that lowland riding is way too boring to even contemplate, it's just not going to happen.
85 is fine.

So lower octane is better for higher elevations?

 

[tkent02]

You don't need as much octane up here, as the air is less dense. Wide open throttle lets in less air than at sea level, so the tendency to detonate is lessened. 85 is enough for these low compression engines.
Another way to look at it, if you have 20% less dense air, it is exactly the same as having 20% lower compression ratio, so lower octane fuel is just fine.
It also helps that it's not likely to be 110 degrees F at 10,000 feet.
The flip side of this is we get less power, all normally aspirated engines make noticeably less power up here than they do at sea level.
The higher you go, the less power the engine can make.
A 1000 cc bike at 10,000 ft goes about like a 650 at sea level, without the high RPM kick.

 

[bccap]

Here are a couple of websites that can help you track down gas stations that might still have non-oxygenated gas yet.

http://www.buyrealgas.com/ http://pure-gas.org/

I run what the manual says too, usually in the middle. Though I have noticed that at higher altitudes the bike seems to want a higher octane? I'm at 3,800/4,000ft now and do alot of my riding at 6,000 to 8,000ft+ in my area. With my idle set at about 1100 rpm, it will barely idle at the higher elevations, so I bumped it up to around 1400.

Lol, haven't heard the term 3/4 race cam in ages, that is a misnomer you valve duration and lift lol.[/QUOTE]

I realize that, but that's what it was called then, it was an Abarth racing cam, but without as high of lift as what was termed full race then. I have no idea what the duration and lift were now, that was in '73.

Thanks for the links. Good stuff. But if the EPA sets the rules, how do they get away with it ? Not that I'm complaining.

 

[Steve]

I ran high octane, leaded fuel in my '70 Fiat 850 Spider

Wow, somebody else that has been shoe-horned into an 850 Spyder. :clap: :clap:

I had a '69 model for a couple of months until someone turned left in front of me.

I use Chevron 94 for my bike. But my motivation is primarily to avoid ethanol.

Avoiding ethanol is probably OK, but I'm not sure that using 94 octane gas is the way to do it.

Higher-octane gas has fewer BTUs per gallon and burns slower, so you will not get any more power by simply putting it in your tank.

I run 89 in the summer, 87 in the winter. If I wanted to try to squeeze a couple extra HP out of it, I could run 91 and advance the timing a little but meh. I'm not really all that into speedin' around on my little 550.

As I just mentioned above, you won't get any more power by simply putting higher-octane fuel in the tank, even if you do advance the timing so it can all be burned by the proper time.


.

 

[7981GS]

You don't need as much octane up here, as the air is less dense. Wide open throttle lets in less air than at sea level, so the tendency to detonate is lessened. 85 is enough for these low compression engines.
Another way to look at it, if you have 20% less dense air, it is exactly the same as having 20% lower compression ratio, so lower octane fuel is just fine.
It also helps that it's not likely to be 110 degrees F at 10,000 feet.
The flip side of this is we get less power, all normally aspirated engines make noticeably less power up here than they do at sea level.
The higher you go, the less power the engine can make.
A 1000 cc bike at 10,000 ft goes about like a 650 at sea level, without the high RPM kick.

That much is true.
I have a fun car that gets the front wheels up in the first two gears at Sea level and at 5,000 feet, it barely gets the wheels up in first!
As a racing buddy said "It feels like the car is chained to a tree doesn't it?"
That car, STILL REQUIRES more than 93 octane to avoid audible knocking just like at Sea level.

Eric

 

[Billy Ricks]

I look at it this way.....30 years ago when my bike was produced there was none of this high octain gas was there ? So why use it today, I put in the cheap stuff, now mind you I have not filled up the tank in a long time, but once I do, it will be the low octain stuff.....

I ahve been known to be wrong in the past, and this might be one of those times, but I think I will be safe, and at $1.50 a litre for the good stuff, well NO Thanks....my SUV get's enough of that already

Back in the late '60s and throughout most of the '70s you could buy 100 octane at any station. It's what was called Ethyl.

 

[Guest]

I P!ss in my tank. Runs fine but if I plan on doing a lot of riding I have to drink a lot of beer.

 

[bccap]

Avoiding ethanol is probably OK, but I'm not sure that using 94 octane gas is the way to do it.

Higher-octane gas has fewer BTUs per gallon and burns slower, so you will not get any more power by simply putting it in your tank..

I'm not looking for extra power. Only to avoid the ethanol. But I'm getting the impression from some of these posts, that it may not be good for the engine ? Suzuki's manual states 85-94. Are you saying that 94 is bad for the engine?
Or just not worth the extra cost?

 

[Allie]

You don't need as much octane up here, as the air is less dense. Wide open throttle lets in less air than at sea level, so the tendency to detonate is lessened. 85 is enough for these low compression engines.
Another way to look at it, if you have 20% less dense air, it is exactly the same as having 20% lower compression ratio, so lower octane fuel is just fine.
It also helps that it's not likely to be 110 degrees F at 10,000 feet.
The flip side of this is we get less power, all normally aspirated engines make noticeably less power up here than they do at sea level.
The higher you go, the less power the engine can make.
A 1000 cc bike at 10,000 ft goes about like a 650 at sea level, without the high RPM kick.

Thanks. Once again, I get it after that explanation.

 

[1_v8_merc]

I run 100LL in my 750 sometimes, just to give it a break from that ethanol garbage.
Usually I'll just mix it with 93 octane...she runs excellent with it.
(hey the manual calls for Leaded OR unleaded 92 octane...)

The 650, I run 87, because it's a factory motor, and the manual calls for it.

 

[koolaid_kid]

My GS used to ping (detonate) on 87 and 89 octane. Really sucked on rallies when we got into a tiny town that only had one station and it only had 87 octane. Once I put in a Dyna S ignition and timed it with my timing light I was able to run 87 octane in it.
I only run the highest octane in the GPz because the compression ratio is around 11.00:1.

 

[mike_of_bbg]

I have a Pure station here in town that I try to frequent for my carbureted fueling needs. They have non-ethanol blends in 87-93. My GS has never pinged on 87. The cars with fuel injectors and high-pressure fuel pumps get whatever excuse for gas I can get the cheapest. Though, I've never had an issue with the oxygenated blends or letting gas sit in anything before except for my Honda mower. Which reminds me, it's time to drain that mower's tank and drop the contents into the Briggs-powered mower. That Briggs will drink anything.

Last time I looked at my local gas station pump, it said the Octane rating was using the (R+M)/2 method. And there's nothing available here below 87 or above 93. So it looks like I can't buy anything that doesn't meet Suzuki's requirements of 85-94?

Oh, I've also heard that ethanol (among its other properties) is an anti-knock additive, so I'd expect to find more of it in high-octane gas. Motors actually designed for pure ethanol can run much higher compression ratios than their gasoline counterparts.

 

[Guest]

In a carbureted vehicle not that has not had the mixture adjusted for modern fuels (richened to compensate for lower energy content), ANY regular ethanol will tend to run leaner, hotter, and might detonate. Since the 89+ gas has a higher octane rating, it is more resistant to detonation. This does not, however, do anything to improve the running hot/lean situation, and just masks the problem.

The right thing to do is sort the jetting. First of all you will probably set it a little rich just for good measure, making it run cooler than from the factory, but if the fuel in the tank is a low ethanol blend, you are now properly jetted for 10% ethanol you can run 10% Ethanol 87 all day long/oxygenated fuel and not have any problems. If you drive through an area with non blend gas, you can fill up and while you might run a little rich, at least it won't hurt your bike.

 

[koolaid_kid]

spchips, you may wish to reconsider your terminology. Ethanol 87 is blend of up to 87% ethanol. Around here we use Ethanol 10 in octane ratings of 87, 89, 91, 92 and 93.

 

[Guest]

spchips, you may wish to reconsider your terminology. Ethanol 87 is blend of up to 87% ethanol. Around here we use Ethanol 10 in octane ratings of 87, 89, 91, 92 and 93.

Post edited. I know what you mean. I live on the coast and it is unheard of to use high ethanol fuel like they do in the midwest, so i wasn't thinking about it this way.

 

[koolaid_kid]

Yeah, when I moved into my current house I was surrounded by cornfields. It has been built up since then, but I can still walk down the road to some.
Around here E85 is sold in select stations, and lots of vehicles are now "flex fuel" vehicles, meaning you can run pretty much anything and the computer will make adjustments as required.