This post is definitely a saga of "two steps forward, one step back" as I work towards getting the old Zed roadworthy.
Solving Brake Light Problems
With the carburettors back on the bike, I went to start it up. This revealed a new problem; a warning light on the instrument console started flashing rapidly and annoyingly. The brake light wasn't working. Pulling the front brake lever also didn't make the light come on, so it wasn't just the rear brake light switch.
Changing the bulb made no difference, so that wasn't the cause. I cleaned up corrosion in the bulb holder and electrical connections behind the number plate, which also didn't work. This put me into a big routine of checking the electrics over more thoroughly, which showed up that it was all in a pretty poor state. Before this, I didn't even realise that the shrivelled black rubber thing behind the left side panel was the brake light failure indicator switch !
I cleaned connectors all through the circuit, and came to the conclusion that the bike's electrics had definitely suffered from deterioration and corrosion while it was laid up.
The electrics on this old bike had always been a small point of weakness (typical of bikes of that era, and definitely better than the damp spaghetti Yamaha often seemed to use !), and it had 40 years of history of replacements, repairs and modifications. Many of them had used the standard pre-insulated bullet connectors sold in auto parts shops. They are actually pretty rubbish. They aren't waterproof and this means they corrode quickly.
Luckily, I found a source of original-type electrical connectors and bought bullets, blocks, and a set of professional ratchet crimping pliers which are much better than the cheap ones from Halfords. If you are in the UK, they are https://www.bikerstoolbox.co.uk/ - as always, they haven't sponsored me to promote them, I just think their products and service are amazing so I am happy to give them a shout-out.
Using their products, I rebuilt the wiring loom for the rear light cluster on the bike, and that solved the problem. I also replaced the ignition switch (photo below) with the correct one and re-made the block it plugs into. The one I removed was a 1980's bodge, where I had needed to replace the original, damaged when someone tried to steal the bike, but the 4-wire Z650B1 ignition wasn't available and I had to fit the 6-wire Z650C1 ignition switch (which meant cutting off the block and using bullet connectors).
I forgot to take a photo of the nice tidy new wiring I made before putting everything back, but here is a picture of the old awful wiring I replaced, together with the headlamp which was the next job.
Fixing the Headlamp
As you can see from the photo above, the headlamp shell was in a dismal condition. Most of the silvering inside had faded and there was a lot of surface rust, so the reflector was beyond saving.
The Z650B1 originally had a traditional filament bulb which created about as much illumination as a very dim candle. I had made a temporary bodge many years ago involving an H4 bulb in a BMW K100 bulb holder, held into the hole at the back of the reflector with a Heath Robinson style arrangement of thick rubber bands and bits of old wire coat hanger.
It was time to replace this, so I picked up a Lucas-pattern 7" sealed unit and fitted it, replacing some poor wiring and connectors in the process.
Although I am trying to focus on work that gets the bike closer to being safe, rideable and legal right now, I couldn't help myself when it came to fitting up new indicators and stalks. I managed to find a set of original-design stalks at Z-Power - rare, most places only seem to have the Z900-style ones with the mushroom-shaped base rather than the flat plate used on the Z650. The old indicators and stalks were so cosmetically awful that I just didn't want to keep looking at them, so since I had the headlamp shell open anyway, I swapped them over.
My Supervisor
While I was doing all this work, our neighbour's cat came around. He loves spending time in our garden, it's full of interesting places for him to hide, and wildlife to watch. But he decided to make himself at home on the fleecy inside of the bike cover and make sure I kept working....
