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Thread: 1986 r80rt fuel mileage

  1. #1
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    1986 r80rt fuel mileage

    My fuel rate is quite inconsistent, i.e. 40 m.p.g...49 m.p.g.... Researching this issues, I came across a site where one logged and charted his fuel rate from his R80RT 1986. His average was approximate 45 miles per gallon and his best was 68.3 m.p.g. Why such a variable range? Had my values adjusted, carbs balanced...I am certain there are many causes and effects. Is this machine known for this?

  2. #2
    Administrator 20774's Avatar
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    68.3 mpg? Did he live any Canada by any chance?? Wow, to get that kind of mileage (imperial gallons or not), I think you'd have to be traveling downhill most of the tank!! Plus, how do we know that his speedometer is proper for his final drive?

    There are truly a lot of variables and it's probably most connected to the right wrist. Drag goes up by the square of the speed, so it doesn't take much push the mileage down. Tire pressures, road surfaces, type of driving...are you droning along at one constant throttle setting or are there frequent stops?

    I don't think the R80RT is known for any more variability in fuel mileage than any other. Actually, I think some are worse, barely getting into the 40s.
    Kurt -- Forum Administrator ---> Resources and Links Thread <---
    '78 R100/7 & '69 R69S & '52 R25/2
    mine-ineye-deatheah-pielayah-jooa-kalayus. oolah-minane-hay-meeriah-kal-oyus-algay-a-thaykin', buddy!

  3. #3
    Old man in the mountains osbornk's Avatar
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    My 86 R80RT has always gotten around 45-50 MPG over the last 13 years.
    'You can say what you want about the South, but I almost never hear of anyone wanting to retire to the North.

  4. #4
    Registered User lkchris's Avatar
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    You'll have to go downhill to get 63.

    One of the surprising things that goes against conventional thinking is that an R100RT is quite likely to return better fuel mileage than an R80RT. The R80RT engine spins a lot faster due to the rear drive ratio.

    An R80 engine only needs to spin 1.25 faster than an R100 to displace the same amount of air/fuel through it. How about 5000 rpm vs 4000 rpm? That's pretty close to actuality.
    Kent Christensen
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    '12 R1200RT, '02 R1100S, '84 R80G/S

  5. #5
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    mileage

    my 86 R80RT gets about40-44 miles per gallon,low end if riding on interstate,at 70 turning 5000 rpm,

  6. #6
    Registered User Anyname's Avatar
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    I think my 86 R80 would have to be towed to get over 40 MPG. I have only had a working odometer for a fairly few miles, but I think it gets abut 35 MPG, Spark plugs look right too. Lots of city miles though.
    BMW R bike rider, horizontally opposed to everything...

  7. #7
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    Well, looks like my R80RT is in the ball park. I may have to relocate and send that site where a R80RT owner charted his mileage and had a rather HIGH m.p.g.

  8. #8
    Administrator 20774's Avatar
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    The website that reported the 68.3 mpg is here:

    http://www.fuelly.com/driver/ritz/r80

    I wouldn't really trust the numbers from this person. It takes him a year to burn off a tank it seems. The previous fillup before the 68.3 doesn't show miles ridden or MPG. My guess is that he partially filled 10/15/11 and then "caught up" on the next fillup on 12/1/12 and didn't take into account the total miles ridden since the partial fill on 10/15/11.

    Bogus data, really!
    Kurt -- Forum Administrator ---> Resources and Links Thread <---
    '78 R100/7 & '69 R69S & '52 R25/2
    mine-ineye-deatheah-pielayah-jooa-kalayus. oolah-minane-hay-meeriah-kal-oyus-algay-a-thaykin', buddy!

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