Another KZ750 E Resto-mod Build

Hi All,

Still a new member here but I have been working on a 1981 KZ750 rebuild of a rebuild.

This bike I have had in the Family since before 1987 (dont know exact date my Dad had it traded-in). Prior to this date it was crashed and below is the list of damage.

• Bent rear sub frame behind shock mounts
• Engine Timing case sheared off at the crank
• Tank caved in on RH side
• Broken Rear brake assy and the Stay for the passenger pegs was broke in half
• and exhaust pipes on RH side were completely damaged

And no I don't have photos as this was before the digital age  

In 1987/88 I did a rebuild had the cases welded, hand machined to re-fit timing plate and assy. The rear stay welded, bondo repair the tank. Straightened the frame.
Then I got creative and added a GPZ 550 front fairing to it and painted the whole bike "Kawasaki Green"
I rode it for a couple summers and did a bike trip with a buddy out to Calgary for the Stampede and then got married and parked it until 2008

Then I got it out of Storage one wintery day and brought it home.

PS not sure if I did the pictures correctly but posting and will see


 

I'm unaware of anyway to post visible images from Imgur here.  You would be better off uploading your photos through the standard forum photo tool.  Just be sure to click "Insert All" photos before posting.

There are several really nice 750 resto-mod projects here.  Looking forward to seeing yours...

Welcome 

Nessism thanks for the picture help.

I will see if I can add some more  

Thanks again  

So I am going to try and add some pics here and I hope I did it right.

So to pickup after my last Post I brought the bike home and worked to get it running again. After some carb work I got it running with my son helping so we jumped to the next generation.

But Life got busy and the Kawasaki sat in the corner as it needed new paint and some more TLC.

Jumping ahead to 2021 and thinking it was time to get the Kawasaki back on the road. When I started going thru the bike and looking at ideas and options I decided I wanted a update front end and went with a 2008 Triple tree off a ZX6R. Found a company making Stems with bearings to match old bikes to new front forks. I had to then build all new mounts for the GPZ550 Fairing I was using and Mount the gauges.



Then I Got it into a roller


Most of you will also notice that I put a different rear wheel to match the ZX6R front wheel. I got a Versys 650 Rear wheel and Axle and brake assembly and mounted that with new swing arm axle plats. (I have not welded together as I am still working/designing how to do it all)

Next Step was to strip it back down. I removed all the wiring and started new with a Mo.unit Blue control and rewired the bike


As I have started to document this I realize that there are many "mini" projects I have done. Its hard to get this into something to share. But maybe I can list what I did so far.

• Swapped out the front forks and triple tree from a 2008 ZX6R 
• Designed and made new Fairing / headlight mount to the ZX6R forks
• Fabricated new Gauge mounts to ZX6R Top Clamp
• Rebuild original Gauges - Speedo is now GPS driven. Built and designed and programmed by me.
  • Used a GPS module with a ESP32 Development board and programed the GPS speed to be converted to a analog signal to drive a small stepper motor to move the needle and added 2 LCD screens to show digital speed and GPS signals to replace analog trip and odometers
  • Tach is still gear driven but with new face
• Switched out the sprockets to a more modern standard 520 chain size (also to match new rear wheel)
  • Broke the transmission case and chain guard getting old front sprocket off...hello ebay)
• Re-wire the entire bike with mo-unit blue, new Rectifier, new Lithium battery, no ignition key as it uses phone blue tooth proximity to turn on.

Think that brings me to current of the engine teardown.

If any one is interested in those other mini projects let me know. I can share my details as I get better at this posting with pictures process for the forum.


 

Jaerho218_750E wrote:

If any one is interested in those other mini projects let me know. I can share my details as I get better at this posting with pictures process for the forum.

 

Silly question!  Of course we want to see your mini projects photos!  Please share as you have time!  Some of us live vicariously though the projects of others these days!  

And we also follow along as motivation to "finish" our own little projects    

Good to see you figured out the pic thing. Looking forward to more.

Mini-Project: New GPS Speedo

When I added the new front end from the ZX6R I lost the ability to run the cable from the front wheel so I needed another method. Since I did not want to deviate from the original look of the tach and speedo I started to look for what I could.
When searching for Alternative Speedometers I can across a Arduino build a guy did for a SIM flying game. So I started learning about Arduino.
Arduino for those that dont know .... Arduino is an open-source electronics platform based on easy-to-use hardware and software. Arduino boards are able to read inputs - light on a sensor, a finger on a button,  - and turn it into an output - activating a motor, turning on an LED. You can tell your board what to do by sending a set of instructions to the microcontroller on the board.
Phase 1
So I built one using a reed sensor to read a magnet on the wheel and send that output to the Arduino. Then I replaces the Odometer and Trip with snall OLED displays only .96" across.
Had to learn the software language and develop code but I already had experience with coding so was not to bad. 

Below is a shot of one of the boards. Used this to develop the code with then used a NANO Arduino to build the unit for this first development phase
[img][IMG]https://www.kzrider.com/images/gallery/details/kz_750_fours_8/1981_kz_750e_mods_20240317_1600848957.jpg[/img][/img]

This is the Built up speedo with the Nano board


this is the OLED display


This is the side view of the X27.168 GM style Stepper Motor

As you can see I used the housing (metal part) from the original speed as a base and mounted the stepper motor to the bottom.
I did change some of the Screen outputs as I move forward in the process and the top screen now shows the speed and the needle moves and matches it. 

And to be honest this took months of coding, wiring it re-wiring it. Frying a Nano board as I hooked it up wrong. Having to get new needles as I broke one after so many on/off for testing. But the major drawback came from when I went to try and mount the Sensor and magnet to the wheel. This turned out to be more difficult than anticipated and I didnt like the extra wires being fed down the forks. I started to do more research and found that a GPS speedo is not much harder than what I had built so far. The stepper motor and displays would still be used just a different input from the GPS and that is Phase 2 (next post)

Hope this reads well enough with enough details to show what I did. Again any questions let me know.






 

Phase 2

So after the previous trial and error I started to see how to develop a GPS Speedometer. I ordered a NEO-6M GPS and started to write new code. There was more to learn and many hours spent watching Youtube videos by other smarter people but I hit a road block and was having some Arduino programming issues. Turns out my new program was too large for the arduino memory. So I moved to a ESP32 development board which was more powerful and had more memory. But it also created some other issues and had to add some more hardware as I was running 2 displays and needed a multiplex board to control the signals to the displays.
I finally was able to get the signal from the GPS and get the ESP32 to read the data and give me a speed. Took many days driving around the block in my truck to see if I could get a GPS signal and a reading or output of speed to the display.
Next was the conversion of GPS speed to a value the stepper motor could use. Another trial of learning and tweaking the program. I learned that the KZ750 speedo gauge face was not fully linear in angle as the how the Stepper worked. but more research and I developed a bias compensation or offset for every 10 km/h increased from zero then reduce it after 120 km/h.
Next was how to get this all on the bike as I had first intended to put the board into the headlight bucket but now I had to also mount the GPS antenna. Found a great location in the tail under the rear cowl. I bought a electronics box and mounted everything in it and extended all the wiring to plug into the speedometer. 

ESP32 Development board



Multiplex board (I apologize for blurry pic but only one I had)



GPS antenna (will sit on top of electronics box)



Wiring exiting out of box and running to Speedo



The box and the wiring.

This post is the final look and install of what my gauge design became. Since I split/disassembled the gauges I needed a way to assemble them back together and mount to the original holding bracket.
I did design and have them cut out by a laser cutting company. They consist of a main plate to hold the 2 gauges and then 2 trim rings and several screws to attached to main plate.




And if you read this I bet you are asking what about the hole where the ignition key went...thats going to be another "mini" project but it will be cool if I say so my self.

I hope everyone is enjoying the pics and the descriptions.