1982 gs850gl poor fuel economy

[Guest]

Ok well first off, this forum is awesome you guys have helped me alot more than I could ever thank you for. That being said I have a problem, I have a 1982 gs850gl and it is just sucking the gas down, on average I get about 140 miles per tank, I would appreciate anything you guys can tell me about this thank you

[Steve]

First things first, please change your font to a darker color that is easier to read.

When you say "140 miles to a tank", is that when you switch to reserve or when you run dry?

My wife's bike is the same as yours (click link in sig to see it) and we regularly go 140-150 before switching to reserve.

You only have a 4.5 gallon tank. It is about 3.5 to reserve, so that would be an even 40 MPG, which is on the low side of average, depending on how you ride.

We have found that riding in the 55-60 MPH range gets the best mileage, and terrain doesn't matter much. Probably the best mileage we have seen (almost 59 MPG) was in the mountains of eastern Kentucky. The worst mileage (about 29) was on the freeway, doing about 75-80, into a headwind, tryingn to keep up with a group of Wings that was in a hurry for lunch.

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[Dave8338]

I average between 43-45 with mine. 40 may be a little low but as Steve mentioned, it largely depends on how you ride. Have you looked at your air filter lately?

[Charger739]

No haven't looked at the air filter, also I get about 140 before reserve this bike really has a 1 gallon reserve?

[Steve]

... this bike really has a 1 gallon reserve?

That is what it's advertised as, I have not verified it personally.

If you would like to have some peace of mind, why not measure the tank and do a fuel gauge calibration at the same time?

Do this in any order that makes sense to you.

Drain the tank completely. Take the tank (either on or off the bike) to the gas station and fill it up, you will see what it actually holds. This is "total fuel capacity."

With the full tank on the bike (and the bike on the centerstand), run a fuel hose from the petcock into a catch tank of sufficient size (4 gallon minimum). With the petcock in the RUN position, apply a vacuum to the vacuum port so the gas will flow. Do not use the REServe or PRIme settings for this. Turn the ignition key ON, watch the fuel gauge. Note where the gauge needle is pointing when the gas flow stops, that is where you will need to flip the petcock to REServe.

Move your fuel line to another container, move the petcock lever to PRIme. This will draw from the same place as the REServe, but will not require any vacuum for it to run. Measure the amount of gas that came out this time. This is your "REServe capacity." Note your gauge needle at this position, too.

Ideally, you should take the bike (or the tank) AS-IS to the gas station and fill it again. There is a possibility that there is a small amount of gas left in the tank, but that won't come out while you are on the road, either, so you will now have an idea of your "useable fuel capacity", which might be just a little bit less than your starting "total fuel capacity".

The difference between your "useable fuel capacity" and your "REServe capacity" will be your "main fuel capacity".

If you would like to adjust where the needle is pointing when the main tank runs out, that is easy to do. Just empty the tank, remove the sending unit, bend it up or down to adjust the needle. Reinstall the sending unit, add enough gas to get it over the REServe point, test it again. Personally, I like to have the needle right at the transition from white to red on the gauge. That way, if it's in the red, I know I am already on REServe. If you adjust your float, you should also note the new position when the tank is empty, then compare that with where the needle is pointing when the key is OFF, so you know the difference.

Yeah it's time consuming and a bit fiddly, but you only have to do it once (per bike), and makes it so much easier to KNOW what your fuel level is and when you will be approaching the REServe mark.

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[Charger739]

I would worry about the fuel gauge except it had been cut off by the previous owner... Sad what ignorance causes lol

[BassCliff]

Hi,

For an "L" model with the smaller tank, that sounds about right. What is your miles per gallon? If I rip on my bike I get 150 or less before I hit reserve. If I take it easy I can get 180+ before I hit reserve. The regular "G" models have a 5.8 gallon tank (22 liters). I ran my bike about 30 miles past reserve the other day and still put in only 4.8 gallons.

I'll get 41-43mpg at 70mph on longer trips. For my regular freeway commuting and running errands I get 38-40mpg. On two lane highway, taking it easy, fun riding (65mph or less) I've gotten as high as 49.5mpg. I've also gotten less than 35 by ripping through the local canyons with a heavy wrist.

Keep the valves adjusted, the carbs clean and sync'd, ignition/charging system in good repair, tires properly inflated, fluids fresh, go easy on the wrist, and you'll do just fine in the mileage department.


Thank you for your indulgence,

BassCliff

[Charger739]

Thanks everyone I really like the family feel to this site you guys l, thanks for everything, really wish that I had people close by that knew more about older suzuki bikes just wish I had the money at the moment to rebuild it to I want it to be restored to its old power and shape