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History of the Yellow Box Speedometer Corrector

Beginnings of a new invention
Like many inventions, the Yellow Box Speedo Recalibrator was created out of necessity.
Back in 1999 a sportsbike speedo recalibration product did not exist, and there was only
an old-fashioned analog product to suit some cars. This was frustrating for one super nerdy
electronics inventor with a brand-new Suzuki TL1000R motorcycle, an excellent bike but
the stock speedo read 5% too fast and with changed sprockets the speedo got even faster.
Clocking up mileage on the odometer faster than actual too...


The Yellow Box solution for speedo errors
The Yellow Box was created in 1999 as a custom one-off solution for this specific
problem. Purpose-built to meet the exacting requirements of it's reliability-obsessed
creator... The world's first microcontroller (digital) speedometer corrector!

"It must be small, light weight, built to last a lifetime, easy-to-set the needed
correction, easy-to-change the correction at any time for new tyres or gearing changes
for the track, it must be built tough and rugged enough to handle the harsh Australian
climate, and most importantly be highly reliable and extremely precise to ensure
accurate real-time correction - so the speedo WORKS."




Version 1      
Other TLR, 'Busa and Suzuki owners wanted one for their bike - and the Yellow Box
version 1 was born.

From humble beginnings, as a one-off custom solution for an annoying problem, it was
not long before word spread through the motorcycle forums and message boards and the
Yellow Box became the unique new must-have product on everyone's aftermarket wish list.




Version 2      
With the popularity of the original Yellow Box for Suzuki motorcycles, owners
of other bikes wanted one too.

With the Yellow Box version 2, Honda, Yamaha, Kawasaki and most other popular
motorcycles could also enjoy an accurate speedo. Many Honda sportscars also
came to rely on the Yellow Box for speedo calibration.

The Yellow Box v2 shrunk to 2.5 x 1.8 inches and became known as the world's
smallest and most rugged speedo corrector. Software upgrades included a new,
intuitive, easy-to-use correction adjustment system.




Version 3        
During 2001 we released an even smaller and lighter Yellow Box. Our version 3 product
received an algorithm speed improvement and two versions were produced; one for Hall-effect
sensors (3-wire sensor type) and one for inductive-coil speed sensors (2-wire sensor type).

Growing in recognition with its proven performance and trusted reliability
the Yellow Box v3 found its way onto pickup trucks, 2WD/4WD and utes, being
especially popular for speedo correction on rugged Toyota vehicles.

With its new tiny size, fast responsive correction algorithm and (as always)
our 10-year replacement guarantee, the legendary reliability of the Yellow Box
continued to cement our place as the manufacturer of the world's premier
speedo recalibrator product.

All the standardised Yellow Box user friendly features, test modes and the
flashing light system continued into this version. A new KPH-MPH conversion
mode was added to provide conversion for imported vehicles.

Yellow Box v3 Instructions
Using the Yellow Box v3     yb3_using.doc
Installing the Yellow Box v3     yb3_insta.doc
Calibrating the Yellow Box v3     yb3_calib.doc
Correction Ratio Table v3     yb3_table.pdf



Version 4        
In 2008 the yellow Box received a cosmetic facelift with our super-compact version 4.
The Yellow Box v4 continued to include all of our long-trusted reliability, ruggedness
and user-friendly features but now in a custom styled design making the Yellow Box
smaller and lighter than anything else on the market.

We had also introduced plug-n-play wiring harness sets for most of the popular motorcycle
models from the major brands; Honda, Yamaha, Kawasaki, Suzuki, Ducati, Cagiva, Triumph
and MV Agusta.

The Yellow Box v4 also received performance improvements like a wider correction range
from +/-50% to +/-100% and a new output test for testing the speedometer during installation.
It featured both KPH-MPH and MPH-KPH conversion for imported vehicles and convenience
when travelling abroad.

Yellow Box v4 Instructions
Using the Yellow Box v4     yb4_using.pdf
Installing the Yellow Box v4     yb4_insta.pdf
Calibrating the Yellow Box v4     yb4_calib.pdf
Correction Ratio Table v4     yb4_table.pdf




Version 5        
We updated the Yellow Box in 2012 with improved computer processing speeds,
changes to the way the correction ratio was set, and further styling and weight
reduction refinements giving it a great new look.

The Yellow Box v5 continued our design philosophy of being built to last a lifetime
and of course carries our famous 10 year replacement warranty.

Expanding our range of plug-n-play wiring harness sets for popular Harley Davidson
motorcycles, Can-Am snowmobiles, and adding new plug-n-play options for more car
and 2WD/4WD models from; Toyota, Jeep, Honda, Lexus, Mitsubishi and Hyundai.

Performance improvements for the Yellow Box v5 included a massive increase in total
correction range to a full 10:1 to 1:10 range, and added more testing modes.

Yellow Box v5 Instructions
Using the Yellow Box v5     Yellow Box v5_ Instructions.pdf
Installing the Yellow Box v5     Yellow Box v5_General Splice Installation.pdf
Calibrating the Yellow Box v5     Yellow Box v5_Setting Speedo Correction.pdf
Yellow Box v5 Harness wire colours     Yellow Box v5 wire colours.JPG
Yellow Box v5 "2-wire" Install Diagram     Yellow Box v5_Wiring Diagrams - 2-wire.PNG




Version YBX  
In 2021 we proudly introduced the Yellow Box YBX. This new Yellow Box received a
big jump in processing power to a 32bit processor which enabled further performance
improvements like automatic speed sensor detecting. This makes it compatible with
a wider range of speedometer and tachometer systems and we no longer offer separate
Yellow Box models for different applications, this new YBX model does it all!

The Yellow Box YBX now has a dedicated green light to show the vehicle's speed sensor
signal in real time, ideal for testing during installation. And as always, a red light which
flashes to show the ratio switch settings so you can confirm the switches are working
and are set correctly.

Other performance improvements were added like a faster response time and micropower.

Based on customer feedback we returned to our user-preferred system of switches for simple
"set and forget" speedo correction ratio setting and added a dedicated switch to set the output
signal waveform type making the Yellow Box YBX compatible with more vehicles than ever before.

Yellow Box YBX Instructions
Using the Yellow Box YBX     Yellow Box - YBX 2021 Instructions
Installing the Yellow Box YBX     Yellow Box - General Splice Installation
Yellow Box Harness wire colours     Yellow Box - Splice Harness wire colours
Install Diagram for "2-wire" sensors     Diagram for "2-wire" inductive coil sensors



Every Yellow Box unit we have ever made is covered by

  If it fails within 10 years we will replace it with a new one!

Over 22 years history of trusted reliability, backed up by our 10-year replacement warranty!


Built for longevity
  • Made by Australian craftsmen who CARE about reliability
  • Every unit is human inspected and computer tested at many stages
  • High quality components from large brand-name manufacturers
  • Rugged spike filtering of power and inputs
  • Internal software designed for total reliability
  • No chemical capacitors or other parts that fail with age
  • All parts over-rated using a large safety margin
  • Gold plated switch contacts
  • Double tensioned connectors
  • Epoxy encapsulated for vibration and water resistance
  • Legendary 10-year warranty!


    Thank you!
    To all our happy Yellow Box owners over the past 22 years and beyond we wish to express our
    sincere gratitude for your ongoing support and your love of our product. You have helped to
    make the Yellow Box Speedo Recalibrator what it is today! Thank you all so very much.

    All of us here at YellR wish you safe riding and driving!
    "With the confidence that comes from knowing exactly how fast you are going."


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