Need Feedback: Fuel Economy/MPG 1981 GS850

[TallBoy]

i got a 81 gs850 that was super mint until yesterday when i dumped it on a dirt road...those are the breaks i guess. my question is a simple one, what are other people with the 850 getting for fuel economy/mpg . i am getting 30...tops, and im not driving like a madman. its got new plugs, oil, air filter, carbs looks pretty good from a bowl inspection. ive seen other 81 gs850's advertised for sale online saying they get 40-45 mpg, one stooge even put 50+!! so what gives? i am assuming looking at the carbs that the needles have never been adjusted from the factory but has anyone leaned out there bike (moved the needle position to allow less gas in)? thanks for the help, TB
ps, in the crash i smashed up my guage case, anyone got a set on some old parts bike??

[smegger68]

My old GS850 I owned 10 yrs ago gave about 45 mpg. I'm guessing yours is running a bit rich.

[mortation]

i got a 81 gs850 that was super mint until yesterday when i dumped it on a dirt road...those are the breaks i guess. my question is a simple one, what are other people with the 850 getting for fuel economy/mpg . i am getting 30...tops, and im not driving like a madman. its got new plugs, oil, air filter, carbs looks pretty good from a bowl inspection. ive seen other 81 gs850's advertised for sale online saying they get 40-45 mpg, one stooge even put 50+!! so what gives? i am assuming looking at the carbs that the needles have never been adjusted from the factory but has anyone leaned out there bike (moved the needle position to allow less gas in)? thanks for the help, TB
ps, in the crash i smashed up my guage case, anyone got a set on some old parts bike??

I was just trying to calculate this today myself, I have an 83 GS850GLD. a quarter of a tank is about 1.45 gallons. I use about a quarter of a tank of gas going to work and back each day. It is about 12 miles one way so a round trip of 24 miles a day. So since these are all guestimates I would say I am getting about 18 - 20 MPG.

Monday I am going to check it exactly to see what I am getting cause those numbers look like crap :P

[TallBoy]

the rich theory is certainly on the top of my list. the engine sounds like a dream and it runs/performs excellent. im holding out for more comments. if i got 45 mpg i think id **** a brick.

[smegger68]

You got fruity sounding pipes on it? That'll kill your fuel consumption if you havent tweaked the carbs from standard.

[TallBoy]

everything is stock. and just based on a visual of the carbs and needle position it looks like they have never been moved from factory preset.

[arveejay]

I just bought and reserected an 80 850G and sold it this week to a coworker. It is getting 44mpg with half the mileage at 75mph on the interstate and the other half on highway 55mph speeds. You've got serious problems if you can't get at least 40mpg.

[Steve]

We just got back from a 2,000 mile trip to Nebraska. My wife's 850 averaged 42.77 mpg for the entire trip. Of course, that's with the saddlebags and trunk loaded and travelling 65-70 mph most of the time. While we were there, we went on a group ride where speeds were more like 55-60 and that tank was 46.65 mpg. Hot weather did not help any. A couple of years ago, we took a trip to Colorado. That trip was at a more leisurely pace, the average was 45.98, with a high of 49.98 in the mountains around Durango! We have gotten into the low 50s, just tooling around the back roads around home.


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[bradleymaynar]

While I can't help on what a possible solution might be, I will add that stop and go travel, ie city driving, will greatly reduce your mpg. My 1100 can see about 110 miles of city driving before I put gas in it. The guage reading empty, it's typically 3 gallons to top off. Out on the open roads I can make 150 miles before having to fill up with the same amount. The bike is stock with the exception of a 4:1 pipe.

Brad bt

[Nightmare]

My bike (80, 850GL) is only getting 30mpg... I know one of the POs rejetted the carbs without changing the air filter, ignition, exhaust and to the best of my knowledge, cam and crank... I KNOW one of my cylinders is running VERY rich (can't seem to fix that one either... sigh) so i'm not surprised by my fuel economy.

[chef1366]

Sync the carbs.
Check the spark plugs for a rich condition.

[Steve]

I KNOW one of my cylinders is running VERY rich (can't seem to fix that one either... sigh)

Any chance that your rich cylinder is #2? If so, you have a bad diphragm in the petcock.
Best bet is to replace the entire petcock as most of the rebuild kits seem to be worthless.


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