Welcome, Guest
Username: Password: Remember me
Electrical
  • Page:
  • 1

TOPIC:

Theoretical Q reg. ZN Instruments KPH vs MPH 6 years 11 months ago #16480

  • Bucko
  • Bucko's Avatar Topic Author
  • Offline
  • Platinum Member
  • Platinum Member
  • Posts: 669
  • Thank you received: 164
Is the digital speedo on a ZN Model user selectable to display either Miles per Hour or Kilometres per hour?

And on a related issue: can a US model ZN's analog odometer, calibrated for miles, be physically swapped out for one calibrated for kilometres, or does the entire instrument package need to be swapped (if the goal is to show total kilometres)?
Hello from Canada's We(s)t coast.

Please Log in or Create an account to join the conversation.

Theoretical Q reg. ZN Instruments KPH vs MPH 6 years 11 months ago #16486

  • scotch
  • scotch's Avatar
  • Offline
  • Sustaining Member
  • Sustaining Member
  • Posts: 1891
  • Thank you received: 832
With regard to the Mechanical Speedometer: I've seen a few posts over the years regarding the Embarrassing, Disappointing and Demoralizing sight of an 80 MPH speedometer on a 120 HP, fastest production bike in it's time, speedometer! I empathise! I'd want a REAL speedometer too ! It would seem reasonable to presume that the differences between the KPH speedometer and MPH speedometer would be dictated by the speedometer mechanics specifically. I say this because I've never seen a "1300" speedometer drive-gear advertised as MPH or KPH specific.
That leaves us with a Drive-Gear that's used for both KPH and MPH. Thus: the speedometer guts are different. If we subscribe to this theory - "The speedometer-cable RPM's are the same for KPH and MPH" - Then there must be two differences internal to the speedometer head to take into account MPH or KPH.
1) The Hair-Spring that returns the needle to Zero would be tensioned LESS for KPH. Given that 62 MPH is equivalent to 100KPH , less spring resistance would allow the magnetic-drive (impulse-coupling) to take the needle to the corresponding higher reading ( needle position). Another way of putting it: Lessen the tension on the hair-spring so that a previous 50 MPH indicated on the MPH dial would now be 80 MPH on the same dial. Then simply apply an aftermarket face-plate that reads in KPH.
2) The odometer gearing would also be different to allow more kilometers to register per given rotations of the speedometer cable.

Theoretically: You could replace the 80 MPH face-plate with a 240KPH face plate but you'd have to increase the pre-load on the hairspring so it responded proportionately to the higher speed range using the same cable RPM. It's the same adjustment that would have been used to calibrate the speedometer (any mechanical speedometer) originally. I'll guess that this calibration would be nothing more then connecting the newly assembled speedometer-head to a cable, driven at a specific RPM and then tensioning the hair-spring to give the correct needle position. Outside of the factory, It would take some trial and error but don't see this as the real concern. The problem would be the odometer reading. The counters and their gearing off the cable input would have to be driven 33% faster to account for the MPH to KPH difference in scale. Don't see anyway of achieving this.
This takes us back to the speedometer drive-gear on the front wheel. Some how you'd have to find another Kawasaki make for the same wheel diameter/axle diameter and coupling to the hub that was intended for a KPH instrument. Theoretically would spin the cable faster, relative to a MPH speedometer. That with some luck would account for the odometer, but you'd still have to adjust the needle hair-spring for final accuracy of the indicated speed.

CRAP ! Should have just said: "You'll have to swap out the MPH speedo head for one in KPH" !

or try to find something like this that you can adapt to the wheel or cluster end of the speedometer cable


Oh well. Maybe this "turned on a light-bulb" for someone !
1980 KZ 1300 sr# KZT30A-009997
Always High - Know Fear !
Attachments:

Please Log in or Create an account to join the conversation.

Last edit: by scotch.

Theoretical Q reg. ZN Instruments KPH vs MPH 6 years 11 months ago #16487

  • scotch
  • scotch's Avatar
  • Offline
  • Sustaining Member
  • Sustaining Member
  • Posts: 1891
  • Thank you received: 832
No Light-bulbs? There's got to be someone out there who can slice and dice this into oblivion. Anyone replaced an 80 mph for a 240 KPH ? If so, you could confirm you used the same (front-wheel) speedometer cable drive.

OH, the beauty of electronics. Push-hold- access- push-push - select - KPH - push !

Anyone ?
1980 KZ 1300 sr# KZT30A-009997
Always High - Know Fear !

Please Log in or Create an account to join the conversation.

Theoretical Q reg. ZN Instruments KPH vs MPH 6 years 11 months ago #16494

  • zed_thirteen
  • zed_thirteen's Avatar
  • Offline
  • Platinum Member
  • Platinum Member
  • Posts: 528
  • Thank you received: 137
I have a B2 which had an 80mph speedo on it. I replaced this with the UK speedo which is 160mph (I think) with an odometer that records total miles. The speedo drive is the same on all KZ and Z 13's

The UK speedo has MPH around the outside of the dial and I think KPH inside that - but the trip and odometers are in miles.
1980 KZ1300 B2 Touring/A2
1990 ZZ-R1100 C1
The following user(s) said Thank You: scotch

Please Log in or Create an account to join the conversation.

Last edit: by zed_thirteen. Reason: typo

Theoretical Q reg. ZN Instruments KPH vs MPH 6 years 9 months ago #16853

  • Bucko
  • Bucko's Avatar Topic Author
  • Offline
  • Platinum Member
  • Platinum Member
  • Posts: 669
  • Thank you received: 164

Bucko wrote: Is the digital speedo on a ZN Model user selectable to display either Miles per Hour or Kilometres per hour?


I have verified that the ZN will indeed display current speed in either MPH or KPH, user selectable.
Hello from Canada's We(s)t coast.

Please Log in or Create an account to join the conversation.

  • Page:
  • 1
Time to create page: 0.080 seconds
Powered by Kunena Forum