[lexcassi]

Hi everyone!

A dear friend of mine gifted me a 2007 Honda SH 125. It’s not running and has been abandoned in his yard for a couple of years…

It’s in pretty rough shape, but I’ve already given it a wash with a pressure washer to get rid of the moss , and it already looks much better!

I’ve started to strip it down, and the lights are completely destroyed, while the wiring is in very bad shape. I’m planning to redo it entirely using multipolar wires and upgrading the connectors to IP68-rated ones.

I’d like to replace the old instrument panel with a digital one (if possible, managing the data flow—such as coolant temperature, oil change warnings, etc.—from the ECU) and swap out the headlights for new LED ones. I’ll modify the plastic fairings and mounting points as needed. I’m also considering using a Speeduino ECU to control everything and pairing it with a Raspberry Pi to add advanced functionalities.

Although I don’t have prior experience working on scooter electronics, I do have experience with software development in various languages, electronics (PLC), and IoT systems for industrial machinery. I’ve also found a manual online and gathered some information about the scooter’s components:

1. Ignition switch: Controls the scooter's power on/off.
2. Instrument panel: Includes indicators such as:
- Fuel gauge.
- Speedometer.
- Digital clock.
- Coolant temperature gauge.
- Turn signal indicators (left and right).
- High beam indicator.
- PGM-FI (Programmed Fuel Injection) malfunction indicator.
- Oil change indicator.
3. Battery: Provides power to the scooter's electrical systems.
4. Fuse box: Contains fuses to protect against overcurrent.
5. Starter motor: Engages the engine for starting via a push button.
6. Regulator/alternator: Generates and regulates power for the scooter's systems and charges the battery.
7. Electronic fuel injection system (PGM-FI): Manages the air-fuel mixture for the engine.
8. Bank angle sensor: Shuts off the engine in case of a tip-over.
9. Headlights and taillights:
- High and low beams.
- Position lights.
- License plate light.
10. Turn signals: Blinking lights for indicating turns.
11. Horn: Operated by a button on the handlebars.
12. Electronic control unit (ECU): Manages engine parameters and electronic systems.
13. CBS (Combined Brake System):
- Sensors for brake fluid level.
- Hydraulic system controlling both front and rear brakes.
14. Electronic fuel pump: Supplies fuel to the injection system.
15. Handlebar controls:
- Headlight switch.
- Turn signal selector.
- Headlight passing switch.
- Horn button.

In your opinion, which products would best suit my application? Which components would I need to replace or upgrade to ensure compatibility with the Speeduino ECU?

Now that this opportunity has come along, I’m excited to get started and rebuild it from scratch. I’m very handy and a quick learner, and I’d love to share the results of my weekend work with all of you over the coming months to get your feedback and advice!

Thank you in advance for your valuable insights!

[PSIG]

Welcome. I have a very similar situation with a 250 scooter that needs some love, so I'll be following this. First question - why change anything, rather than just repair the wiring and what's there?

[lexcassi]

Hello!

The harness is in very bad shape, and I think one of the main electrical issues could be the original voltage regulator. I read on an enthusiasts' forum that older models like mine often had problems with it and the plastic connectors. In the second photo I sent, I highlighted in red the voltage regulator I plan to replace and the location where I was considering installing the new control unit.

After further evaluation, I’ve decided not to proceed with the Speeduino for this project because it’s an overkill for what I need, as the electrical system is quite simple and uses only a few sensors. I was really excited about it but decided to wait for a bigger project to fully utilize its potential.
I’ll be using new LED lights without any electronic control components, relying solely on physical switches. For the basic sensors—such as fuel level, engine RPM, coolant temperature, etc.—I’ll connect them directly to a compatible digital dashboard.

In parallel, I’ll install a Raspberry Pi with some expansions to provide additional information, such as fuel quantity, through a simple mobile app I’ll develop. Additionally, I’ll include GPS tracking functionality to help in case of theft.