Owned Your Bike For 15 Years Plus?

[BlackandBlue]

I bought my 83 GS1100E in 1992. A few months later changed the front sprocket from a 15 to 16 tooth. Now, the reason for this thread. In 93 I went on a day trip. Got a little over 60 mpg!!! On the last couple of tanks of premium I got 47 and 44. The bike is the same except new tires and about 8k more miles. Runs great. I can't prove this theory but I suspect the fuel is being contaminated with ethanol even though the pumps don't have the ethanol sticker. Anyone here notice a big or gradual decrease in mpg? And I know mpg has been discussed in another thread but I looking for responses from long term owners.

[1980GS1000E]

I have owned my '84 900 Ninja since it was new and I always seem to have gotten pretty lousy mileage, around 30. I have never seen 60 out of a 4 cylinder. That kind of mileage is usually reserved for singles. I can't even get above 40 if I try to. The GS seems to get around the 30 mark, also. I am sure there are additives in the gas, but it hasn't really changed my mileage. I have noticed slightly better fuel economy using 87 octane instead of premium, though.

[ohgoodtimes]

Though it technically wasn't my bike i have talked to me cousin about this before when i was talking to him about what to expect. He told me when he was riding the ninja 500 back in 89 when new he would get about 65 to 70 miles to the gallon. I now have the bike and I get closer to 60 and i ride her real sweet and use synthetic oil, all the maintance is kept up great. Don't know if it is because of the gas or an aging bike, but I guess i can say i have noticed a difference.

P.S. the bike has 32k on it, thats more than my 83 gs, i don't know how this happened

[seuadr]

geez. and here i was happy with 40-45mpg's on my 1100

[isleoman]

I bought my 82 GS1100ez as a left over in 84. I've used regular (89) and premium (94 & 93) and have never gotten better than 45 mpg. I suspect that your initial measurement was thrown off by some error or fluke.

Your sprocket change may have gotten you 10% better mileage but I doubt you would have seen better than 50 mpg consistently. Octane is Octane I don't think they've changed the way they measure it.

In the northeast you can't buy anything but ethanol. I had a old Harley dude come out of a gas station in Conn. recently to start the pump for me. He says " So you want me to fill her up with rice." I thought for a second and replied "Unfortunately, your only selling corn"

I think there is a little less total energy in blended gas/ethanol. I thought the whole country was using 10% ethanol?

Be happy with your 47 mpg thats still pretty good and what I would have expected.

[Zook]

Octane is octane, but the additive that helps achieve that octane (alcohol) has less energy than gasoline, therefore you get worse mileage.

Don't believe the line about alcohol being better, etc. It is hard on fuel lines and carb parts, it requires more to get equal power as gas and most motor oils break down when subjected to it.
Plus it attracts water, so our tanks will rust faster and our engines pick up the water before the fuel, so they quit running.

[BlackandBlue]

I bought my 82 GS1100ez as a left over in 84. I've used regular (89) and premium (94 & 93) and have never gotten better than 45 mpg. I suspect that your initial measurement was thrown off by some error or fluke.

Your sprocket change may have gotten you 10% better mileage but I doubt you would have seen better than 50 mpg consistently. Octane is Octane I don't think they've changed the way they measure it.

In the northeast you can't buy anything but ethanol. I had a old Harley dude come out of a gas station in Conn. recently to start the pump for me. He says " So you want me to fill her up with rice." I thought for a second and replied "Unfortunately, your only selling corn"

I think there is a little less total energy in blended gas/ethanol. I thought the whole country was using 10% ethanol?

Be happy with your 47 mpg thats still pretty good and what I would have expected.

One thing for sure my commute to work is not helping. About half is on a bypass traveling between 70 and 80 mph. The ride I mention was on two lanes with 55 limit. Maybe at the time I didn't top it off when filled up.

[Nick]

Yeah, the ethonol(sp) is causing a drop in mileage. While its better for the atmosphere and all it's cutting our mioleage. I hear it's a... 10% drop average in mileage.

[Nalayah]

In my '99 Grand Prix SE with a 3800SII, I get six more MPG with Regular 87 sans-ethanol than 89 Octane E10.

You should run 87 octane in your bike, unless you've a much higher compression than stock. Octane is nothing more than resistance to pre-detonation.

[Steve]

With NO other changes, try a couple tanks of Regular gas instead of Premium.
I will bet that your mileage will go back up.
Maybe not quite back up to 60, but it will go up.

[Zook]

I think you meant detonation, aka "pinging.
Then there is pre-ignition, which is the a/f mixture igniting before the spark lights it off. VERY destructive. Your engine is acting like a Diesel.
Pinging is caused by the combustion process taking place too quickly. To slow down the rate of combustion we increase octane.
Alcohol burns slower than gasoline, so we can add it to gas to increase octane.

Etanol may not be better for the atmospere in the long run because we need to create electricity to heat the stuff to run the still, or burn a fossil fuel at the still, or at both the still and power plant.

Plus it takes more than a gallon of diesel fuel to make a gallon of ethanol, which doesn't have the BTUs available as the gas it replaces, so we burn more, so we must make more....you are working at a loss.

You guys with alky-free fuel are lucky!

Steve is right, with a stock engine you don't need premium fuel. Premium fuel burns slower, so you get less power from it in your GS because of the lower (stock) compression.
You would be surprised at how many new bikes are designed to run on regular and have MUCH higher compression than our GSs.

[Steve]

... with a stock engine you don't need premium fuel. Premium fuel burns slower, so you get less power from it in your GS because of the lower (stock) compression.

And, because it burns slower, it tends to leave deposits on the pistons and valves. These deposits can get red-hot and cause the incoming mixture to ignite before the spark. Now you need 'premium' gas, but only to cover up what 'premium' gas started in the first place.

Note that 'premium' is in quotes. That name does not mean that it's better gas or has more power in it. In fact, 'premium' gas has fewer BTUs per gallon than 'regular'. Where the extra power comes from is the higher compression ratio and longer duration camshafts. These will heat the incoming mixture to the point that it will light the fire before the spark does, so you need to use 'premium' to keep that from happening. Since 'premium' gas burns slower, you have to advance the spark to light the fire sooner so it's all done by the time the piston is ready to go down on the power stroke. See, it's not even the ignition advance that makes the power. That is just the cover-up that lights the fire sooner for the 'premium' gas, which is itself a cover-up to resist the accidental ignition by compression pressure-related temperatures.

OK, RapidRay, and any of our other resident racers, how far off is that?


.

[heathen]

you are spot on with your assessment. we run my son's camaro bracket car on e85. had to increase fuel flow 25%. did pick up time about .1 in the 1/8 mile, and it runs cooler. e85 is 85% ethenol and 15% gas for those that don't know. it has 115 octane and the racing gas we were using was 111 and cost $8.50 per gallon and e85 cost $3.40 a gallon because the gov. subsidises it a $1.00 a gallon i figure i can get some of my tax dollors back.

[Larry D]

You know, you guys kinda scare me a little. LOL LOL!!!

[Planecrazy]

You should run 87 octane in your bike, unless you've a much higher compression than stock. Octane is nothing more than resistance to pre-detonation.

I think you meant detonation, aka "pinging.
Then there is pre-ignition, which is the a/f mixture igniting before the spark lights it off. VERY destructive. Your engine is acting like a Diesel.
Pinging is caused by the combustion process taking place too quickly. To slow down the rate of combustion we increase octane.
Alcohol burns slower than gasoline, so we can add it to gas to increase octane.

Steve is right, with a stock engine you don't need premium fuel. Premium fuel burns slower, so you get less power from it in your GS because of the lower (stock) compression.
You would be surprised at how many new bikes are designed to run on regular and have MUCH higher compression than our GSs.

And, because it burns slower, it tends to leave deposits on the pistons and valves. These deposits can get red-hot and cause the incoming mixture to ignite before the spark. Now you need 'premium' gas, but only to cover up what 'premium' gas started in the first place.

All very interesting information ... unfortunately that doesn't change the fact that ever since I bought my 1100G it has "pinged" on anything BUT premium fuel ... so that's what it gets exclusively. Assuming that all the above info is correct, it would seem that my engine is now "coated" with deposits causing the "pinging." Short of tearing down the motor, any suggestions on how to reverse the situation so that the engine would once again run well on regular?

Just an aside, I have absolutely no power problems with this bike - it has it in droves, but due to the pinging it insists on premium.

Regards,