Speedometer setup cable

To change the settings and calibrate the Daytona speedo that is on Dean's motorcycle, there are two buttons on the underside of the unit. Alternatively, an extension cable can be fitted. As calibrating the speedo required pressing a button while traveling along, it needs at least one of the buttons on the handlebar.

The buttons just connect a lead to ground, so I soldered up a couple of push buttons I had handy. My intention was to simply tape them to the handlebars. They were only going to be used the once.

I got carried away. I quickly designed and 3D printed a clamp to hold them on the bars.

If it was going to be a permanent fixture I would probably have designed it to look a little different but for our purposes, it did a good job.

I deliberately removed one of the button caps, so there was no doubt about which button to press to set the calibrated speed. Having first set the speed to miles instead of kilometres, Dean rode the bike and followed me driving the car at 40mph to set the speed as per the instructions. It did what we expected and the speedo now reads roughly the right speed.

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Oil filler cap

The oil filler cap on Dean's motorcycle leaked, so I put the lathe to good use again.

We wanted to retain the original stylish top.

As I don't have a milling machine, I put an end mill in the drill press chuck and used that to form the cut-outs for the cap to fit over.

The spring clip was ground down from one taken from a budget filler cap bought off of eBay. It was secured with two M3 screws.

I have not glued on the cap yet. We're going to check it does not leak before I make it permanent.

It looks good and fits in perfectly.

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Update: 14 Sept 2022

It's been test ridden and no leaks, so I've now glued and pinned the top in place.

I've also used a better fitting rubber washer, 36mm ID 3mm thick.

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Custom motorcycle wiring harness

I have done a lot of electrical work on cars but this is my first time connecting up anything for a motorbike.

Dean has been building a custom motorcycle, pretty much from scratch. The frame and engine were once from different Yamaha's and Dean has adjusted the frame to his taste and assembled it with all the components to make a bike of his design.

He wanted the wires to be tidy so I've made up a complete harness.

I've started with the circuit diagram from a similar era Yamaha, which I had to understand and in the process correct. The engine is a 1985 to 1989 Yamaha XT600 which is similar to the XT550 of the same era.

From that circuit I created my own diagrams, specific to Dean's bike and then added a harness layout for them. Once that was all worked out and I was happy with it...

I proceeded to make up the harness. I've used braided casing, cloth wrap and heat shrink tubing for a tidy job.

It only took a couple of days, on and off, then we were able to fit it to the bike and test it.

It did not go to plan and a bit of investigation was needed. The ignition switch was faulty, so with that bypassed, the harness worked as intended. There was also a slight fault on the connector to the tail light which had a bent pin, easily fixed.

The run for the top tube is a little longer than it needs to be but the whole thing is discretely fitted to the frame.

As a bonus, Dean has a near complete electrical manual for his custom motorcycle.

Download:

Updated July 2023 (revised cable run lengths and test details for some of the components.)

Dean's motorcycle electrical manual (PDF)

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