'02 f650gs dakar odometer

[scoobs]

Hi,
As a result of the recent gas price increases I've started paying more attention to my MPG on both bikes- and have discovered a major discrepancy between the Odometer (total bike mileage) and Tripmeter (resetable mileage counter).
The odometer has shown an increase of 20 miles on a recent ride, and the tripmeter displays a reading of 29 miles for the same distance travelled. I believe the tripmeter is accurate as the journey was one I make regularly and is roughly 30 miles door to door.
Anyone have any thoughts on this- it certainly explains why my mileage ridden last year was so low.
thanks,
Ian .

 

[157990]

What mileage are you currently getting? My '01 Dakar will pretty consistently give me 60 mpg ridng fairly seriously. Worst since I got it last year was in the mid 50's, best so far was a touch over 64.3.

 

[gblawler]

I consistently get 60 mpg riding in town. On the highway it varies. If I ride 65-75 mph on the interstate, I get 60 mpg. If I ride 55 mph on 2 lane highways with only a small number of towns to stop and go through, I have gotten as high as 69 mpg. I read a magazine article a year or two back about an adventure rider who claims he got close to 80 mpg. I would suspect he was riding at a consistent moderate speed, like 45 to 55, with little stop and go. Guys I ride with who have 1150 or 1200 BMW's tell me they get around 45 mpg on the highway and close to 50 mpg under ideal conditions. The great mileage is one the things I really like about the Dakar, especially at the gas prices now. When I was riding a 250 as a kid, it was considered a mid-sized bike. The large touring bikes were 650's, like the Triumph Bonneville 650. Back then, a 650 was considered to be a large engine and I still think of a 650 as having plenty of power.

 

[scoobs]

My problem is what to do about the disrepancy between my two mileage recording devices- I assume they are fed from the same source, anyone have any idea on how to fix this??
Cheers,
Ian

 

[gblawler]

The reason I gave you my mpg rundown was to help you to determine which one was correct. If the trip odometer is giving you mpg of around 60, that further confirms your suspicion that it is correct.

The way to nail this is to get out on the nearest interstate and note your mileage on both the odometer and the trip odometer as you go by a mile marker. Ride 5 or 10 miles for good measure by counting the mile markers and check both odometers at the end.

I had a BMW car many years ago that gave me odometer readings that were way less than they should be. I pulled the speedometer out of the car and took it apart and found there was a plastic gear that was cracked. The crack produced a gap between two of the teeth which would cause it to occasionally stop advancing. If you watched the odometer, it would "tick" as the driving gear was skipping in this gap. By "tick" I mean you could see the tenths on the trip odometer advance slightly and then drop back the same number.

I drilled out the hole in the center of the gear so it was the same size as the shaft and superglued the crack in the gear and superglued the gear to the shaft. I had the car for a number of years after this and it continued to work fine. When I sold the car, the odometer was around 180,000 but on the mileage certificate I indicated I could not certify the mileage because the odometer had been broken for some time. I would guess it had around 30,000 more miles than the odometer showed.

In my BMW car case, the problem was with the trip odometer and the regular odometer, probably because the regular odometer was further down the gear train. In your case, you could have a similar problem but further down the gear train such that the trip odometer is fine, but you are skipping teeth between the trip and the regular odometer.

 

[scoobs]

Thanks, i'll try the "mile marker' test, but the damaged gear doesn't apply in this case as the readouts`are both LCD and I'm assuming the input is also digital.
cheers,
Ian

 

[sgborgstrom]

There is some information from the Chain Gang to be found here:
http://faq.f650.com/GSFAQs/SpeedoABSSensorFAQ.htm#Solutions:

In a nut shell, check the connections under the seat and the sensor at the rear wheel.