The airhead gas mileage thread.

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

  1. civhatch90

    civhatch90 Been here awhile

    Joined:
    Jul 23, 2007
    Oddometer:
    130
    Location:
    NJ
    I know we do not have these bikes because of great gas mileage but just curious, what kind of mpgs are you guys getting?

    List model/year/mods.
    #1
  2. Mark Manley

    Mark Manley Long timer

    Joined:
    Apr 3, 2010
    Oddometer:
    1,110
    Location:
    Back home in the UK
    I am a fairly steady rider, cruise at 60 mph, rarely accelerate hard and both my '83 80 G/S and '91 80 GS usually give me about 50 mpg imperial gallons that is 40 mpg US gallons. The best I have had from both is about 55/44 on a steady run and down to 40/32 in difficult conditions into a very strong headwind.
    I do get more than most of my friends who have airheads and the same with tyres, about 10,000 from a rear, 15,000 from a front.
    Something I find that makes a big difference is carb condition, I rebuild them every 50,000 miles with new jets, needles and lap the choke discs which gives another 3-4 mpg, the figures given are after a carb overhaul.
    #2
  3. Byron1

    Byron1 Been here awhile

    Joined:
    Jul 27, 2012
    Oddometer:
    108
    Location:
    Lincolnshire, England
    I have a 1979 r100rs but have removed the fairing. Ride fully loaded and 2 up. Steadily cruising all day not accelerating hard we consistently get between 45 - 50 mpg (imperial), we can squeeze out more but that is typical for us.

    As an aside sitting at around 3,000 rpm in top gear or speedo shows us cruising at 70mph... We don't go much faster than that. the indicated 70 in reality equates to about 55 though. My final drive is 33/11...

    Our engine oil consumption is somewhere about 1litre every 1500 miles.
    #3
  4. kadesean

    kadesean eyesuck

    Joined:
    Jan 4, 2006
    Oddometer:
    989
    Location:
    Muskegon, Michigan
    I have had 4 different airheads and have never seen 45mpg.

    '79 R100S, '74 R90S, '81 R80G/S, '74 R90/6

    Currently on the unfaired R90/6 I average ~38mpg

    I have previously had an F650GS that I could get 60+ mpg out of

    And on a Buell Ulysses I averaged high 30's, but did get 50+ on one particular trip

    I think I could get better mpg on airheads if I didn't like twisting the throttle so much :)
    #4
  5. senatorperkins

    senatorperkins Adventurer

    Joined:
    Jun 11, 2012
    Oddometer:
    43
    Location:
    SF Bay Area
    sort of goes without saying that for most of us airheads are more about smiles per gallon than mpgs. :D

    awww.. anyway.. 1978 R100/7 with 32mm CV bings, I got 40mpg on the dot, no matter how or where I ride, two up, fully loaded, solo, or not. Oil consumption about 1500miles/liter as well, but I had a number of leaks I just fixed, and now I know not to fill the the max line. Overhauled my carbs, maybe that'll bring my mileage up a bit.
    #5
  6. Foot dragger

    Foot dragger singletracker

    Joined:
    Dec 27, 2006
    Oddometer:
    13,766
    Location:
    chico,just below rag dump(nor-cal)
    There's a whole section devoted to airheads in Oldscool,its all there to avoid clutter here.
    #6
  7. orangebear

    orangebear Long timer

    Joined:
    Aug 12, 2010
    Oddometer:
    1,377
    Location:
    dumfrie scotland
    i am not sure of the mpg as i just work out the miles per tank on all my bikes
    #7
  8. Beater

    Beater The Bavarian Butcher

    Joined:
    Sep 3, 2009
    Oddometer:
    3,701
    Location:
    Atlanta, GA, USA
    I used to get ~45 out of an R80, and ~42 out of an R100 .... once they're dialed in*. Currently, I'm getting ~38 on my '91 R100GS, but In the ~200 miles to a tank, I'm putting about ~20 of 'dirt riding' ... that seems to decrease my mpg :evil .

    * I am a conservative rider. Both bikes had Mikuni carbs, set up by Stan the original owner of Rocky Point Cycles. Both bikes 'set up' only entailed moving the needle a bit leaner.
    #8
  9. slartidbartfast

    slartidbartfast Love those blue pipes

    Joined:
    Dec 23, 2003
    Oddometer:
    5,937
    Location:
    Southern Louisiana or Southern England or ...
    36-44 mpg (US) out of my 1985 R80RT. Worst of 32, best of 48. I usually run between 65 and 80 true mph on the freeway, which will deliver around 38 mpg. The bike is in pretty good shape but with 40,000 miles on it the carb needles and jets are probably worn. I also have never had the enricheners apart for any sort of PM. The 85 has lower compression than earlier examples which will negatively impact both max HP and fuel economy. I'm not sure if the compression reduction is due to the pistons or the head so I have no idea whether there is an easy way to increase it.
    #9
  10. JRP

    JRP Old guy

    Joined:
    Apr 4, 2004
    Oddometer:
    1,562
    Location:
    Hampden, MA
    1983 R80 G/S... stock... normally around 42 MPG
    #10
  11. supershaft

    supershaft because I can

    Joined:
    Sep 9, 2010
    Oddometer:
    9,116
    Location:
    San Francisco Bay area
    '92 R100: 21-42mpg

    '83 R65: 25-39mpg

    '69 R69S 19-38mpg
    #11
  12. crazydrummerdude

    crazydrummerdude Wacky Bongo Boy

    Joined:
    Nov 28, 2006
    Oddometer:
    7,915
    Location:
    El Segundo, CA
    Usually around 40mpg, although I swear I got 59mpg on a tank on my R90 in 2009.
    #12
  13. misnomer

    misnomer Adventurer

    Joined:
    Dec 5, 2011
    Oddometer:
    67
    Location:
    Deserts of Nevada
    I suppose I average 35 or 37 on my '94 R100R - mostly a ten mile freeway commute.
    #13
  14. bikerfish

    bikerfish flyfishandride

    Joined:
    Aug 18, 2010
    Oddometer:
    2,171
    Location:
    western pa
    45mpg on the r100r, usually loaded and two up. On my r100/7, I can squeeze out 50mpg.
    #14
  15. electric_monk

    electric_monk Adventurer

    Joined:
    Sep 24, 2007
    Oddometer:
    15
    Location:
    Dublin
    Fairly energetic riding of my 90 R100GS has consistently delivered 45 miles per Imperial gallon. A recent clean and balance of the carbs and it is now returning 44mpg.
    #15
  16. some_guy

    some_guy Been here awhile

    Joined:
    Sep 26, 2012
    Oddometer:
    144
    Location:
    NoVa
    I figure 40-45mpg most of the time on my 95 R100RT (without the fairings). I run premium from BP or Shell. Combination of stop and go (commuting in NoVA) and highway traffic.
    #16
  17. john112deere

    john112deere Been here awhile

    Joined:
    Apr 3, 2011
    Oddometer:
    101
    Location:
    central VT
    I'm a little obsessive about tracking MPG in my pickup.

    The bike...not so much. Fill it to the nearest whole-dollar amount of gas that'll fit in the tank, ride 'til I hit reserve, repeat. Rarely look at the odometer or number of gallons, never write anything down.

    Every time I've roughed out a number, though, it's been 42.x mpg. That's usually on longer rides with the windscreen and side cases on, highway or backroads, but it doesn't seem to matter if it's all local riding without 'em, either.

    EDIT: '86 R80, about 90k miles. More or less all stock and original as far as I know.
    #17
  18. craydds

    craydds Long timer

    Joined:
    Aug 3, 2010
    Oddometer:
    1,175
    Location:
    Las Cruces, NM
    '75 R90S... 45 mpg. Mostly stock motor - stock heads and cam, lightened flywheel, bored cylinders and oversized pistons, lightened wrist pins. Boyer ignition, stock Dellortos with needles dropped down one notch. I am going to try smaller main jets, got two smaller sizes to test (recommended by Steve from Bevel Heaven). I ride at 4500 ft. elevation and above - up to 11,000 ft. Hope to get a bit better mileage, but it is not all that important - PERFORMANCE is the key.
    #18
  19. SRanger331

    SRanger331 stuff

    Joined:
    Dec 10, 2011
    Oddometer:
    235
    Location:
    NW Ohio
    Stock 73 r60 22k miles. Usually 44-46 mpg us, one tank best of 50.
    #19
  20. Wirespokes

    Wirespokes Beemerholics Anonymous

    Joined:
    Jul 26, 2002
    Oddometer:
    8,697
    Location:
    Jackson's Bottom Oregon
    I think the heavier you are, the worse the mileage.

    The 86 G/S does the worst with 38-44. The only real mod is 1,000 jugs. It might get 46 on the highway, but don't recall as it's been quite a few years since I've travelled very far on it.

    The 77S - RS fairing, 1050 kit and dual plugged tends to get 48 to 50mpg. When I first got it, the jetting was way too rich and timing was off quite a bit. Riding it home from the Bay Area, it got something like 38 - 44 mpg. It's much much peppier now, but I'm betting there's some heavy carbon build up in the combustion chamber that promotes pinging under heavy acceleration in hot weather.

    The 83 850cc R65LS with modified heads and 34 Mikunis is the real surprise. No matter how I ride it, the mileage works out to 49-51 mpg. Like the 77, it had comparable mileage when it first showed up here.

    Most of my bikes have gotten 45 to 50 mpg. Forty seven or forty eight was really common with my 1980 R100T with an RS fairing, no mods.

    My first beemer - 76 R90 got 51 at one fill up, but generally got in the high forties. I tend to not accelerate hard unless passing or for safety reasons.
    #20