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Old 10-22-2012, 10:30 AM   #31
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Joined: Apr 2009
Location: Chewelah, WA
Oddometer: 1,139
Originally Posted by boxerboy81 View Post
I get about 15kpl which is 57kpg or 35.5 mpg.

Needles and needle jet changes?

How much has renewing these improved anyones mpg?

How often should they be changed? Mine have done 80K kms.
Bet they are plenty worn in 80k km's. I replace mine every 30 to 40k miles. At the same time I do normal carb dissassembly and maintenance. I tend to see a 3mpg jump when retuned with new jets and needles. Cleaner running plugs as well.
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Old 10-22-2012, 11:03 AM   #32
Uncle Pollo
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Joined: Jun 2006
Location: Albuquerque, Neue Messico
Oddometer: 47,208
I get better mileage riding two up. Pollobabe will hurt me if i am noot smooth.
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Old 10-22-2012, 11:31 AM   #33
because I can
Joined: Sep 2010
Location: San Francisco Bay area
Oddometer: 8,039
Jet needles and needle jets? I renew them when I can see/feel a wear ridge on the needle. How many miles? There should not be a mileage figure set in stone since it all depends on what model carbs you have. The jets in carbs that have the spring clip last at least three times longer than the jets that have the C-clip. I suspect because the spring clip keeps them from vibrating as much. I buy these tiny little wavy washers to put on top ot the C-clips. They fit right in between the clip and the hold down and keep the needle much more secure. I am not sure but I think they last about as long as the needles held in place with the clips.

Most I have fixed report back a couple to 5mpg better.
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Old 10-23-2012, 10:58 AM   #34
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Joined: Aug 2009
Location: New Brunswick Canada
Oddometer: 312
All over the map

Being the data hound that I am, I keep a running log on all my fuel purchases. Also, since building report engines for the data analysts at work is my bread and butter, I make pretty pictures of it as well. Here's a graph showing the fuel consumption over a five day trip I took in the end of September from NB to PA.

Here's the high and low lights of the trip:

  • Best fuel consumption: 5.21 l/100 km (45.1 Miles/US Gal)
  • Worst fuel consumption: 6.75 l/100 km (34.8 Miles/US Gal)
  • Average fuel consumption: 5.76 l/100 km (40.8 Miles/US Gal)
  • Number of fills: 10
  • Max distance on a tank: 375 km (234 miles)
This was a combination of Interstate (110-140 km/h actual) country road (50-90 km/h actual) and suburban (0-50 km/h actual) riding. My bike is a 1983 R100RT that is bone stock. The interesting thing is the nearly 10 MPG swing based strictly on riding style.

Once the snow flies, and I'm bored at work sometime this winter, I plan on plotting out the whole riding season's fuel consumption. I suspect that the plot for that will look a lot like the one for this trip. Just smoother.

Can you tell I don't want to be working?
Larger than life and twice as ugly!
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Old 10-23-2012, 01:13 PM   #35
Out of the office.
Joined: Dec 2003
Location: Where the Ghetto meets the sea.
Oddometer: 5,845
'83 R80ST Low to mid 30s or ~120 miles to reserve (Single petcock)
'86 R80 Mid to high 30s ~140 miles to reserve (Both petcocks on both switched to R)
'92 R100GS Mid 30s ~140 miles to reserve (Both petcocks on both switched to R)

I weigh around 210 with my kit on, I normally don't have side bags on any of the bikes and the GS has a stock screen, top box and BMW brush guards. I run the windscreen in the most raked back toward the rider postion.
Bike are single plugged and otherwise stock in the induction and exhaust departments.

I use the lowest grade gas ~89 and I get my gas from either a Chevron station or a 7-11 station.
Tire pressure is 32 fr 34 rr check pretty often.
On vacation for a spell
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Old 10-23-2012, 03:38 PM   #36
Beastly Adventurer
Joined: Feb 2006
Location: Bath Uk
Oddometer: 1,692
Twin plugged R90/6. Best is 60 mpg (imperial)

1070 bike. Best is 50mpg imperial
R90s 1070 replica, R90/6
1971 Commando Fastback
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Old 10-23-2012, 05:28 PM   #37
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Joined: Mar 2011
Location: Silver Spring, Md
Oddometer: 8,027
I don't keep records so I don't know. It's not great I think, I do mostly short trips.

I did replace the carburetors on my R90/6 just this week with another pair I've had for many years. I don't know why but I never could get this set of carbs to work very well and never left them on. I found a couple of problems, mainly the jet needles were on the first notch, and figure this might be why they never worked right. Have been adjusting them the last coupe of days and think I almost got it.
Never memorize something you can look up.
---Albert Einstein

Pay your debt, piratejohn.
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Old 10-26-2012, 08:03 PM   #38
Still on 3 wheels
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Joined: May 2009
Oddometer: 4,090
25 on a bad good day....35 on a good good day....

Of course that's on three wheels and a ton of crap aboard

Living proof you shouldn't play with matches
ABC# 1992
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Old 10-26-2012, 08:12 PM   #39
Studly Adventurer
Joined: Dec 2008
Location: Boise, Idaho
Oddometer: 505
My 1983 R100RS consistently returns around 45 mpg (US). I suppose that's partially due to my conservation riding style and the dual plugged heads. As far as I know, the needles and related jets are original to the bike. I'm the 2nd owner, having bought it from a friend. I have new needles but I can't find a reason to install them.
I love my 1983 R100RS! I believe it's one of the best BMWs to ever roll out of the factory.
.................................................. ................
For all we know, this may all be just a dream; we come, we go like the ripples in a stream.
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Old 10-26-2012, 11:08 PM   #40
Rob Farmer
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Joined: Aug 2002
Location: Loughborough, Leicestershire. England
Oddometer: 4,981
i did a long trip in june, just over 6,000 miles all in. My 100GS PD averaged 51mpg over the whole trip. I believe that's around 42 mpg US. Not too bad considering it was fully loaded.
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Old 10-26-2012, 11:37 PM   #41
scaffold builder
Joined: Jun 2010
Location: Eureka ,Calif
Oddometer: 415
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
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Old 10-27-2012, 01:08 PM   #42
because I can
Joined: Sep 2010
Location: San Francisco Bay area
Oddometer: 8,039
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.

supershaft screwed with this post 10-27-2012 at 02:15 PM
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Old 10-27-2012, 01:12 PM   #43
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Joined: Jul 2010
Location: Central Florida
Oddometer: 2,025
74 R90/6 with 105k miles, pretty aggressive on the throttles and will pick up 80 regularly during my commutes. Pretty consistantly 39-40mpg.
1974 BMW R90/6 Bettie #1, 04 Triumph Bonneville
Originally Posted by Martin Blank
loner, lonegunman, get it. That’s the whole point. I like the lifestyle, the image. Look a the way I dress.
Originally Posted by bgoodsoil View Post
Cavemen must've designed them shortly after inventing the wheel.
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