Speedometer

[NoOne65]

so my speedo started acting up like it does when the RR goes tits up but after I replaced the RR it never started working. I am thinking speed sensor itself? Any way to test either of them? anyone have a speed sensor lying around?

 

 

J

[Zero Knievel]

I have a way to test.  Jerry rig a set of multimeter leads to the terminals on the speedometer that get the signal.  Look up the voltage of the signal pulse.  Plug in a multimeter where you can safely view it and ride.  While a pulse, it occurs so fast it will look like continuous current.

 

When the speedometer stops working, if you still show voltage, the speedometer is bad.  If no voltage, it’s likely the sensor or wire harness (least likely).  When mine acted up, I pulled the sensor and found some organic gunk stuck to it...impacting its ability to sense the spinning of the flywheel.  I just removed the gunk, and all was well.

[blackhawkxx]

1 hour ago, Zero Knievel said:

Plug in a multimeter where you can safely view it and ride.

Or put it on the center stand and run it though the gears.

[Zero Knievel]

9 minutes ago, blackhawkxx said:

Or put it on the center stand and run it though the gears.

 

You would think that would work, but if the malfunction isn't predictable (like in my case), it may be HOURS before you see it happen once.  Also, the bumping of actual riding can cause something to happen that will never take place when stationary.  I suppose it depends on how frequently your speedometer is acting up.  Some malfunctions only occur under actual conditions but not in the shop.

[jon haney]

Check the ground first, of course.  There is also a dis-connect on top of the engine for the speed sensor that can get very dirty.

The speed sensor actually picks up the rotation of second gear.  28 teeth IIRC.  I had to know this info to program the data-logger on my drag Bird.

Edited April 16, 2019 by jon haney