The MK1 LeMans I’m trying to restore has what appears to be uber primitive control gear for the alternator. It appears that the field is controlled from the slip rings and that there are three phases for the output from the outer windings although there seems to be another mystery wire coming from the windings on the other side.
I am having to make a brand new custom loom for the bike as we’re using period Kawasaki handlebar switches and owner has supplied me an electronic ignition unit that has the pickups on the end of the alternator shaft. It would make sense to use a modern transistorised control unit?
The alternator itself looks pretty OK. I do note that Electrex World do make a complete replacement alternator unit with mosfet reg/rec. , but knowing my luck this will be incompatible with the electronic control sensors?
I may as well dump those hideous fuses in favour of blade fuses that can be sourced in the event of a side of the road break down.
The owner has also given me a Mistral Exhaust system which I assumed should attach to the footrest hangers, but the brackets are no where near - Any thoughts? I had the bike delivered in boxes and have never worked on one before so have no idea where any of this should go!
The Bosch charging set up may be primitive, but it is actually quite good and simple. It works well if you look after the connections. There is a full explanation of the system here….
As Don has stated, the Bosch Charging system is primative but works very well if kept upto scratch and bearing in mind the system on your bike is 40 years old, its entitled to be a little crusty! Just make sure all connections are tight and clean!
Electrixworld make a very good Reg/Rect for the Bosch system which also works very well. I have one on my MkII LeMans and no issues.
Why the custom loom? If you use Switchgear that has all controls on the L/H side with just the Start/Kill switch on the R/H side, as original, you can just change the Connectors on the Switchgear. Also, after market OE spec looms are available if your original loom is toast.
Also, i have the Elektronic Sache Ignition system on my MkII. It bolts over the Bosch Alternator and does away with the Distributor. Again, no issues and is progammable.
I agree the old Ceramic fuses are not the best, but again if kept clean and tight you should have no problems. Halfords sell them, so easily available.
I have a trade account with Electrex World and emailed them about the regulator for the Bosch alternator, and they have suggested their RR34. I am assuming that one ignores the bottom left connection in my photo, connect top right D- to frame -VE battery and the top right to the green field control connection from the reg/rec?
I’m using pattern Z900 switches as they easily available, look the reasonably period and above all are reliable. The customer doesn’t want the standard clips-ons and as so much is non-standard in his wiring I may as well make a loom from scratch. Also the owner striped the four years before admitting defeat and giving me a pile of boxes, so I have no idea where anything goes anyway, so I may as well treat it as custom! I use only Thinwall wire so the loom will be slimmer and the wire will handle more current than standard PVC wire, so have better longevity.
Are you sure the RR34 unit will work with the Bosch alternator? This system needs a power feed through the charging light to energise the rotor through the slip rings.
In previous conversations on here, the RR45 unit has been used. Have a read of this thread…..
Thanks for that Don - EW gave me bum info. Not sure it’s quite the same since Peter passed on.
I just now have to find somewhere to mount the reg rec as well as whatever coils I end up using. The bike originally had a double ended coil hooked up to some electronic ignition system that was binned by the owner before he handed it to me. He has given me a Sachse unit, but this requires two sing coils. Was thinking about Dyna Mini coils as they are more compact. Used them on my Z13 to good effect.
Do you guys reckon there’s room under the tank for the coils? Never having seen the bike before it was stripped by the owner four or five years ago is making my life very difficult!
The earlier T3 models had the coils located under the tank. I did a Google search to try and find a photo and came up with an interesting previous thread from this forum that may help you.
The standard location for the coils on a LeMans is under the left hand side panel like this. You won’t need the box behind them as that is the voltage regulator.
You should be able to mount the rectifier/regulator under the right hand side panel as that is where the standard rectifier lived or under the headstock so long as they clear the horns if you are putting them back there (as shown in the thread mentioned above). This is my Cali 3 which has a combined r/r unit under the right hand side panel.
