Terrible Gas Milage

[TEX2TL]

I have ran two tank through my new to me 850g and have received around 26mpg. From what I understand this is half of that the bike should be. I don't drive it crazy and have actually baby-ed it quite often. Haven't noticed any leaks either.


Any options on this?

[Dave8338]

Just a quick update on what you have done so far?

As for the 50+ mpg out of an 850...on a 1500 mile cruise last summer the best I was able to achieve, was a solid 37mpg and this was all highway and back-road riding.

[tkent02]

There are literally dozens of factors that can effect mileage, have you gone through every single maintenance procedure and adjustment on the whole bike?
By the way, babying it and lugging the engine is not the way to the best mileage.

They can get 50 mpg in ideal conditions, some riders do it routinely, others never do.

[BassCliff]

Hi,

I've gotten anywhere between 31.5 to 49.5 mpg with my bike depending on conditions and habits. Daily commuting and errands around suburbia leave me with 37-39 mpg. On long freeway trips at 70mph I see 41-43 mpg easily. On two lane highways at 65mph or less I get over 45 mpg.

I suggest all the proper maintenance. Are there any mods to your intake or exhaust?


Thank you for your indulgence,

BassCliff

[Dave8338]

I'm in the never do camp. Just takes all the fun out of riding.

[dr_fosg8]

Unless you are living at the redline that sounds a little low. As the others have said, do ALL regular maint. items and see if it improves. My 1100gl consistently gets 36-39 mpg with a windjammer and lowers and hard luggage.

[Gonzo]

It's funny to hear car manufactures bragging about 30 MPG, and when our bikes don't do 40 or more, we worry. :P Nice problem to have, but still a problem no doubt.

[tkent02]

Cars have less wind resistance than bikes do, that's where most of the fuel is wasted.
Also an engine designed to be fuel efficient would be slow and torn apart by the magazine testers, they would never sell a bike. Newer FI bikes do better but still not over 60 for a full sized bike, unless you putt along like the proverbial little old lady.

[SqDancerLynn1]

I would start with a good carb sync..

[airbornespud]

i just picked up an '82 850L and have only run a couple tanks through it, but i have also noticed that the numbers are a little on the low side, but you have to remember that it's on the larger end of the displacement scale and it'a a four. but, that being said, i'm still in the mid to upper 30's. i don't know what weight oil you're running, but that can change things, along with your warm-up habits. if you're doing a lot of short jaunts around town, that can kill your numbers. if you think it's an indication of a problem, pull the plugs and see if it's running rich or burning oil. it could be as simple as an old air filter or a hung choke cable, or as bad as a major mechanical issue. start with the easy (inexpensive) stuff and work your way towards the big money until you find it.

[tkent02]

start with the easy (inexpensive) stuff and work your way towards the big money until you find it.

It's probably not one big "it", it's likely to be combination of a lot of little things.

[7981GS]

My 850 got the same mileage as my 1000G... 36-38 mpg at 10-20 over, everywhere.
Something is wrong with those carbs and/or timing?

Eric

[TEX2TL]

Sorry pulled a noob move here. I have paper work that a shop rebuilt and sync the carbs but guess its time for me to learn how to do it. Just sucks after having the bike down this past week while working on the stator. But I can't do 26mpg when both my cars are getting 35+. The bike runs fine but does seem like it needs a lot of choke when starting no matter what temp it is. And also seems like it needs a lot of throttle to leave a stop sign or a red light. And me work 9 miles(with 7 red light in between) from home probley isn't to good on it either


Back to BikeCliff libary I go....

[Dave8338]

Sounds like the valves are tight !

I would start by checking the valve lash. My 850, even with a few tight valves, will start and run just fine, without choke when temps are above 70 degrees.
Tight valves can/will lead to all sorts of problems if left unchecked!