K1100 on the Dyno

[bikesnbones]

Won a free dyno run in a dealers competition.
The old brick got a few chuckles as I rode it in.
Graph shows a very respectable 91.9 bhp at between 7,500-8000rpm and a healthy 73.8 ft Lb's of torque at 5,500 rpm.
 :riding:





A couple of things were noted during the test.
The rev counter sticks and stops at 7,000 rpm.
The speedo is under reading quite dramatically.
a reading of 70mph, is a true 61mph
 :dunno2:

[F14CRAZY]

That good ol BMW speedo inaccuracy

[F14CRAZY]

Not hard to fix though

[Freelancer]

If those are rear wheel numbers then they are very good for a totally stock bike.
Let us know when you correct the speedo.

Later,
Freelancer

[kris]

What's with these speedos?? Just when you think you are flying....no wonder the cops don't give me a second look :riding:

[bikesnbones]

Not hard to fix though

Tell me more

[Freelancer]

Not hard to fix though

Tell me more

Check out the "Index" in the Motobrick "Technical Library". There are threads for replacing speedo gears, fixing flakey speedos and for fixing other instrument (tachometer).

There may also be an article on fine tuning your speedo somewhere on this site but a 9 mph differrence is a gear change imo.

Hope this helps,
Freelancer

[Inge K.]

Speedo gears is for the odometer..........to adjust the speedo it's a potmeter at the pcb.
Search the net with the key words K100 or K1100 + speedometer + karamba.

[Freelancer]

Speedo gears is for the odometer..........to adjust the speedo it's a potmeter at the pcb.
Search the net with the key words K100 or K1100 + speedometer + karamba.

Thank you for the correction Inge.  :2thumbup: I just learned something new. Was confused why there was way to adjust the potentiometer but also gears.

Obvious Questions:
Does this mean that the odometer is completley independent of the speedometer?
Does this mean that adjustments to the speedo have no effect upon the odometer?

Thinking a dishonest individual could have a seriously worn out "low-mileage k" with this set up.  :yow
Just seems like a weird and inefficient setup.

Respectfully,
Freelancer

[rbm]

"No" to answer both questions.  The adjustment ensures that the needle is pointing to the correct part of the speedo scale when certain frequency of pulses is present.  The odometer still calculates distance assuming the sender is transmitting 6 pulses per wheel revolution.

A disreputable K-bike seller merely drives the bike around with a disconnected sender if they want to cook the odometer reading.

[Freelancer]

Thank you for the detailed answer, rbm. It is knowledge like this that brought me to this site.
It is knowledge like this and the friendly/amusing characters on this site that keep me coming back.

Respects,
Freelancer

[bikesnbones]

If those are rear wheel numbers then they are very good for a totally stock bike.

Later,
Freelancer

Yep.
Figures measured at the back wheel on the dyno,
BMW claim 100bhp which is obviously at the crank, so 91 at the wheel is pretty damned good.
Someone else I know with the same bike, measured his speed against a sat nav, and it was only a few mph out at 70.
My 9mph discrepancy at that speed is pretty bad.
As soon as I find a way of mounting it, I'm going to get a sat nav on mine, then once I know where the true readings are from 70mph, up to 100mph, I'll put some sticky brightly coloured dots on the speedo.
That's the easiest way.

[rbm]

Why not just adjust the speedometer to correct the error using the potentiometer provided?  It's a 15 minute job, once the instrument cluster is made accessible. Are you aware of Karamba?  The adjustment can be performed in the garage while the bike is on the centerstand using this piece of software.

[ldbeemer]

  The odometer still calculates distance assuming the sender is transmitting 6 pulses per wheel revolution.

Not to highjack this thread, but if an odometer suddenly reads 36% less miles than is actually being ridden, what would I need to look at? If the pulse transmitter, how do check that?
1995 K75 RT, nothing worked on on the drive line in the past 9k miles. The drop in recorded mileage happened in the time it took to use one tank of gas. 300 miles later still registering 36% less miles than I'm actually riding compared to two GPS odometers which have always been within <1% of each other and the odometer.

Thanks
Gene V

[rbm]

If all of a sudden, then I'd be looking inside the cluster at the odo gears. They are fragile and can break easily.  There are repair services available if this ends up being your problem.  http://www.odometergears.com/products/BMW/R+%26+K+Motorcycles/42

[ldbeemer]

If all of a sudden, then I'd be looking inside the cluster at the odo gears. They are fragile and can break easily.  There are repair services available if this ends up being your problem.  http://www.odometergears.com/products/BMW/R+%26+K+Motorcycles/42

If a gear sheds a tooth or more wouldn't it stop reading mileage altogether? Or could a gear just be slipping on it's shaft? causing to continue reading mileage but not the correct amount?

Gene V