I have just completed replacing the odometer gears in a K speedometer.
On a road test today, the odometer was found to be running slow compared to the highway milepost markers over a 50 mile stretch.
When programming on the Karamba program (excellent), The results showed that the odometer is running 2.5% below actual while the speedometer is running 2.7% too fast!
I'm very sure that the gears set installed was the same tooth count as the set that failed (and correct to specs).
I was prepared to re-adjust the speedo for calibration but if I correct the speedo, the odometer will be 4% slow!
I'm considering turning the speedo up another 1.5% which would reduce the odometer error to 1%.
The rational is that a speedo reading 79 mph at 75 actual would seem less troublesome that an odo that runs quite too slow, especially given the fuel warning light errors, the odo error could be critical to running out of fuel......while the speedo error would be to the safe side, perhaps saving a speeding ticket?
I see no option to slow the speedo while increasing the odo.
What would you do?
Regards, ibj....

If the needle had been put back a bit out of line it will happen. I had to get the needle into the right place on the K75 and then they corresponded. The PO sounded like he knew what was what, well he did but he didn't have the physical skills to go with the knollege and as a result "mayhem".

Well, I had the needle off several times & re-installed it so it reads as close to the actual zero spot as possible when at rest (off) I suppose it could be re-installed so it sets at say -2 mph and be about correct......then, when I turn the pot up 2% it will again tread only 2% fast (acceptable while the odo would be closer to perfect. I have to take it apart to put a new O-ring on when it arrives anyway. Once finished I'm gonna try to get $400USD for the entire unit.
Originally, I took a bath on this unit......buying it from an BMWMOA ad....($325)..when it got here, the neutral light did not work. So I sent it back to him for "repair" but for a myriad of reasons.......he turned out to be a looser.........so eventually I had to drive 350 miles and recover it from him in person (still in the box I sent it to him in.
So anyway, I put a used tacho board in it and upgraded the fuel lights as well as changed the face to one with only a single pump image on only one window, installed the all red lenses and new speedo gears.
I would still loose some money at $400.....but I think it's still saleable at that level especially for an original 85 unit with round pins.
Only thing I might have done to otherwise improve it would have been to install a Gortex vented back cover..
Thanks, ibj...

ibjman

Rick,
I went back and made another stab at this tonight. I re-tuned the speed pot and tested it in the Karamba till I had the odo working within 3/10's of a % of what the Karamba screen said. Seems very close. Next, I set the Karamba program at 130kph (81 mph) and gently installed the speedo needle. Testing further I found the speedo was 2 - 3 miles slower than actual at 30 mph indicated and about 5-6 mph too fast at 130 mph. I felt that is an acceptable compromise.
When shutting down,.... the needle return to rest was WAY low beyond the "0". The only option I could come up with was to drill the face adjacent to the 0 mark and install a "stop pin" for the indicator to come to rest against.
Best I could do. What do you think. Is it too "mickey mouse" to sell for large money????
I want to be honest in selling it but I'm buried in it financially & need to recover at least some of my funds.
I hope to get $400 USD for it. I considered putting it on the market with a 10 day money back guarantee.
Regards, ibj...

I would say quite acceptable for speed but I reckon you're right about a rest stop, most speedos have one.
The K75 my wife rides is still a bit out but quite ok and the needle does sit down a fair way but that is OK for the owner but a buyer could be put of. Maybe a tiny rivit of aluminium and peened over at the back, paint it black and no one will see it.
I can just imagine in years to come someone will notice at a rally of vintage bikes that "his" K75 has a speedo stop why is that must be a different year to mine.