The airhead gas mileage thread.

Discussion in 'Airheads' started by civhatch90, Oct 21, 2012.

  1. darklight79

    darklight79 drink it , ride it , nail it

    Joined:
    Jun 2, 2010
    Oddometer:
    1,184
    Location:
    Eureka ,Calif
    So now that they stopped making the pd tank for upgrades ....I seem to be in the low 30s most of the time .... usually wfo ...5k and beyond on a 94 gs
    #41
  2. supershaft

    supershaft because I can

    Joined:
    Sep 9, 2010
    Oddometer:
    9,116
    Location:
    San Francisco Bay area
    For the most part is all about how you ride. It's funny but economy never even enters my mind when it comes to motorcycles. If it did much at all, I would switch to four wheels or a scooter.

    Well . . . that or slow WAY down but why waste a perfectly good motorcycle? IMO, that's what four wheels and scooters are for.
    #42
  3. mfp4073

    mfp4073 Long timer

    Joined:
    Jul 5, 2010
    Oddometer:
    3,006
    Location:
    Central Florida
    74 R90/6 with 105k miles, pretty aggressive on the throttles and will pick up 80 regularly during my commutes. Pretty consistantly 39-40mpg.
    #43
  4. bikecat

    bikecat Long timer

    Joined:
    Jan 20, 2006
    Oddometer:
    1,147
    Location:
    Tropical Far East
    Hiya,

    My R100R is showing a poor mileage of about 29.5 mpg(US) or 35.3 mpg(UK).

    My riding pattern is a daily commute of about 10 miles each way, I usually rev at about 3500 to 4000 rpm and change gear at about 3000. There is a rough spot at about 3000 but it smoothens after that.

    The carbs are balanced, and the jets cleaned. Doe any one have a clue as to what I can do to make the consumption better? To me it seems that there is something wrong if my mileage is so poor.

    Thanks.
    #44
  5. danedg

    danedg Horizontally Opposed

    Joined:
    May 13, 2008
    Oddometer:
    7,331
    Location:
    U-puku-ipi-sing
    Replace your jet needles and your needle jets. Your mileage will improve.
    #45
  6. B_C_Ries

    B_C_Ries Long timer

    Joined:
    Mar 15, 2013
    Oddometer:
    4,391
    Location:
    Imperial Valley, California
    Got 43 mpg on my last trip.
    #46
  7. saranac

    saranac Adventurer

    Joined:
    Jul 12, 2014
    Oddometer:
    35
    Location:
    Puget Sound
    On my '83 R100 with an added RT fairing, usually get in the 40-42 mpg like a lot of other riders of this vintage. Typical 65-70 mph speed
    #47
  8. chasbmw

    chasbmw Long timer

    Joined:
    Feb 19, 2006
    Oddometer:
    2,676
    Location:
    Bath Uk
    I agree with the advice above, your commute does not help, it's not really long enough to get the bike up to a decent running temperature. I don't know your commute, but a decently running airhead can use lower revs without being lugged, try using the 2000-3000 rev band if your commute is in heavy traffic.
    #48
  9. MotorcycleWriter

    MotorcycleWriter Long timer

    Joined:
    Dec 1, 2012
    Oddometer:
    1,596
    Location:
    North Alabama - World's Rockiest Trails
    I did a full carb rebuild, valve check, plugs and wires, and carb synch and was getting around 36-39. Replaced my original cracked coil and it jumped up to 52 mpg! Starts easier than my 14-year younger oilhead.
    #49
  10. BMW851

    BMW851 Piston Broke

    Joined:
    Dec 4, 2010
    Oddometer:
    129
    Location:
    Blue Mountains, Australia
    1988 R100RS

    Average using 98 Premium

    5.8 L/100
    48.9 mpg imp.
    40.7 mpg US
    #50
  11. patiodadio

    patiodadio Motorcyclist

    Joined:
    Oct 14, 2007
    Oddometer:
    374
    Location:
    Backwoods of Kentucky
    My 88' R100RT is dual plugged and gets mid to high 40's mpg.



    .
    #51
  12. TDL028

    TDL028 man of leisure

    Joined:
    Jan 22, 2014
    Oddometer:
    511
    Location:
    Rockville, MD
    84 r80 w. r100 jugs-

    If im being conservative and steady slow cruising I will get around 40-50mpg.

    most of my riding is around town.. so stop and go, lights and spirited riding I usually get like 25mpg. but thats really enjoying and pushing it.
    #52
  13. Beater

    Beater The Bavarian Butcher

    Joined:
    Sep 3, 2009
    Oddometer:
    3,701
    Location:
    Atlanta, GA, USA
    '91 R100GS - Mikuni carbs (20 pilot, 160 main), double plugged - Average 37-38 mpg
    '85 R100g/sifiedRT - Mikuni carbs (20 pilot, 160 main) single plugged - Average 40-43 mpg

    I believe difference is weight and the fact that the GS carries bags.
    #53
  14. slartidbartfast

    slartidbartfast Love those blue pipes

    Joined:
    Dec 23, 2003
    Oddometer:
    5,937
    Location:
    Southern Louisiana or Southern England or ...
    Are those Mikuni round-slides? How do they deal with altitudes?

    Just rebuilt the Bings on my 50,000-mile 85 R80RT, including new needles and needle jets (left needles on third notch from top, which I assume to be stock) and hoping this will improve mileage a bit from the most recent average 37-44 (US)mpg
    #54
  15. Beater

    Beater The Bavarian Butcher

    Joined:
    Sep 3, 2009
    Oddometer:
    3,701
    Location:
    Atlanta, GA, USA
    They are the round sides ... and I've only had them up to ~3,500 feet. Atlanta, GA is right around 1,000 feet, and you only get to 3,500 in the NGa mountains. That being said, there was no altitude effects at all ... (but I wouldn't expect there to be until you get closer to 7,000 feet ... )


    #55
  16. slartidbartfast

    slartidbartfast Love those blue pipes

    Joined:
    Dec 23, 2003
    Oddometer:
    5,937
    Location:
    Southern Louisiana or Southern England or ...
    Thanks. I considered changing to the Mikuni's but have taken my old RT up in the Alps and Pyrenees up to 10,000 feet and I suspect non-CV carbs might cause issues which is why I spent a couple of hundred dollars on parts and quite a few hours working on the Bings.
    #56
  17. bikecat

    bikecat Long timer

    Joined:
    Jan 20, 2006
    Oddometer:
    1,147
    Location:
    Tropical Far East
    I've moved the needle from 3rd notch up to the 2nd notch. Will see if there is a MPG difference. The plugs were showing rich mix as well; have closed the mixture screws a tad.
    #57
  18. Madman1

    Madman1 Adventurer

    Joined:
    Mar 24, 2010
    Oddometer:
    84
    Location:
    Norway
    First ride yesterday, Friday 13th. It should have been ready til May 1st, but. Bike is a 95 RT.
    I wanted to put good engine oil in it. 2 gas stations where I live in the middle of Norway. Gas station nr.1 could not order Mobile 1 V-twin. Went to G.S.2, they could get it over the weekend. So I show up over the weekend. "Only available in North America".
    Back to other station and order Valvoline max life 10W-40. Next day engine got new oil.
    The 3 gear oils already changed. Tank was off, had to change wires to the horns. I unscrew the petcocks, change that red gasket. Tank back on, fill 2-3 litres gasoline. No leaks at petcocks!
    I still have that gas valve thing under the engine cover, so keep ignition on to make sure carbs get fuel. Fumes, actually a moist spot under the bike shows up. Smells like gasoline. Comes from the engine vent hole abeam the starter.
    OK, need to check fuel lines, engine cover off. Fuel lines look fine, so must be that fuel shutoff valve. Unscrew both "T's", change o-rings. Put all fuel lines together for testing leakage.
    All fine, put bike together.
    Yesterday wx not so good. After waiting it out a bit, I decide to go for it. Destination 90 miles away. I might do some shopping there, since they got better beer, and cheaper, than home.
    Ride goes above tree-line. It's cold, and light snow now and then. It melts though, so make it OK. At the store, they only got 11 cans Modus Hoperandi. They, pluss 1 can Dale's Pale Ale, and a 3 liter box with a red fluid, goes in one side bag. The other side bag is loaded with 12 cans of Dale's, and ditto red fluid. Balance/symmetri is important.
    After a coffeebreak, and some groceries in the top box, I'm off.
    Ride home initially very nice, dry road, spiritid. Then 15 min snowshower, had to wipe helmet cover clean!
    At the gas station, where I topped it off at start, I refill. 13,46 liter/296,9 km. 0.45L/10km. 51.8 mpg.
    Bike is basically stock. Dual plugged, Silent Hektik ignition.
    Long weekend here, Monday off, and Tuesday, May 17th, is our national holiday.
    Take care.
    Hans
    #58
    aptbldr likes this.
  19. mfp4073

    mfp4073 Long timer

    Joined:
    Jul 5, 2010
    Oddometer:
    3,006
    Location:
    Central Florida
    since this came back up my 74 r90/6 is now 125k and getting 40-41mpg
    #59
  20. Runaway Train

    Runaway Train The Left-Right Tourer

    Joined:
    Aug 9, 2013
    Oddometer:
    53
    Location:
    Ontario, Canada
    85 R80RT... standard tank what is the fuel capacity?
    Y'all got me thinking about my bikes thirst. I'm going to do some cypherin' this week.
    #60