YAMAHA CS3C
It’s mostly electrics this time along with a light dusting of transmission trauma.
Scoop with another celebratory Yamaha!
And so came the day when it was wiring time, not a process I especially enjoy and not enhanced either by the fact that I’m apparently colour blind when it comes to pale shades of blue, grey or green in close proximity.
On the plus side I have to say the repurposed wiring loom from a CS1C came out well, but I still don’t know why it was in ‘in stock’ or where it came from. As the CS1C and CS3C are fairly similar there wasn’t too much adaptation needed, but all of the old insulation tape was replaced and everything inspected and/or checked with a meter. Using the cable clips and guides, most of it fell into place quite neatly I have to say, but because I don’t have any faith in the ability of ball bearings, grease, powder-coat, etcetera to conduct electricity, I’ve added a few extra earth leads and run them back directly to the battery.
As I couldn’t find a decent wiring diagram of the CS3C I enlarged one from a CS1C owner’s handbook and dug out my official Yamaha RD200 factory manual I’ve had since 1973. As the electrical system realistically changed little on Yamaha’s 180-200 twins I reckoned I was on firm ground here. Before I looked at the bigger picture with the aid of a mate the lid came off the gold-coloured box that sits surrounded by the oil tank and air-box underneath the main frame tube. Often erroneously called TCI unit/ignition module/black box by ebayers and bike breakers, it’s actually the voltage regulator and electric starter relay. There’s no rectifier on any of these electric start twins simply because the generator kicks out DC current. Most of the ills associated with these bikes stem from sticking or corroded contact breakers within, along with bad earths and poorly charged batteries. Poor storage in damp conditions is the usual reason for a raft of electrical issues which can, in perfect storm scenario, see the associated wiring. A gentle tidy of the
points with 1200 grade abrasive paper allied to some electrical contact cleaner should ensure all is well inside. These relay/regulator units can be the Achilles’ heel of CS/RD 200s as their design is actually flawed.
Next up was the flasher unit, which originally looked like it was wearing a fur coat. A gentle clean with a 3M abrasive pad and some GT-85 restored the outer surface and preserved the factory markings – yes I know, anorak moment. Reunited with its yellow passivate mounting clip, it will sit resplendent under the bolt-on seat never to be seen again, but I know it’s been done right!
Whilst at the tail-end, the rear indicator wires were cut to length and terminated, then fitted to the loom. Note how dark green wire is stupidly connected to light green wire – nice one Yamaha! The strange tag on the right-hand-side seat rail is a hangover from when flasher units were hung off rubber carriers on some CS1 and CS2 models; here it’s twin purposes are to confuse restorers and catch the hands of the unwary!
The refurbished horn was next, followed by the coils and atypically for me I’d actually identified where each set of connectors went, which made life much easier; orange to the left and grey to the right. The original brass nuts were long gone so everything went back with serrated washers and stainless steel nuts. These early Yamahas have their coils suspended from a moulded rubber block that fits on to a peg on the top downtube. The block is then held in place by a wrap-around metal bracket, which also conveniently holds the main loom in place.
Batteries aren’t cheap, well, not decent ones anyway, so it pays to protect your investment. Yamaha graced their early bikes with battery trays that were as much about insulating the device from vibration as anything else. Always the first thing to be thrown away by young owners, I’ve added a slice of thick, soft rubber sheet to protect the Motobatt kindly donated by Wemoto before it become nigh on impossible to send batteries out via the
post or couriers. And, of course, it makes sense to hold the battery in place so another hurrah for Yambits who’ve had the correct strap remade.
The actual rewiring of the loom, sub-looms and earths still does my head in. I get the fact that it was a costeffective way of doing things, but wouldn’t a set of properly identified and tagged terminal blocks have been more userfriendly? To this day I fail to see why the Japanese didn’t sort out the carnage that was ‘Satan’s String’ more efficiently. Thank God my mate Dave Jupp was once again on hand to assist and advise because I really struggle in this area. I’d buy him a bottle of scotch to say thank you but he doesn’t drink! After what’s best described as ‘an appreciable time’ we had
the indicators flashing, the tail light illuminated and both brake lights working… result. The headlight still needs a bulb, but other than that we’re sorted hopefully.
Decent progress made, we were almost at the point of backslapping, shoulder punching and shaking hands when Dave spotted a potential issue. The replacement clutch basket we’d fitted to the engine appeared to have a lot of free movement, which we initially thought was possibly a missing thrust washer or similar. With the clutch assembly stripped out it was obvious all the parts were there, but there was slack between the basket and the gearwheel assembly to which it’s fixed. The two are riveted together holding a cush-drive mechanism in place, which isn’t a service item so doesn’t carry a part number. So three steps forward and two steps back – looks like I’ll be dancing the Street Scrambler Boogie for a bit longer then!
Thanks this month to:
Wemoto www.wemto.com
Yambits www.yambits.co.uk My mate Dave Jupp!