-76 3CL with DMC wiring question

cape

cape

Hero member
Location
Finland
I've been trying to figure out what is the original wiring diagram on -76 3CL. Is it the same as on 1974-1977 3C with stop relay? If so, what is changed on wiring if DMC ignition is installed? And finally, is the system missing a voltage regulator causing a risk of over voltage?

Any info appreciated, thanks in advance,
-Sami
 
Cape,

2 different stop relays were used, square (early) and round (later).  One of them grounds the CDI, the other interupts the circuit, don't remember which is which, sorry.

Both the magneto powered CDI (HKZ-Hochspannungs Kondensator Z?ndung) systems have very similar wiring, with the stop relay being the biggest difference.  Things changed a bit with the battery powered BTZ (Batterie Transistor Z?ndung) systems, but the DMC systems for both are the same.  Those supplied for the earlier HKZ ignitions just contain the additional charging coil and the pair of ig. coils.  Both types lose the complete ignition loom which is replaced with that supplied with the DMC.

HKZ-equipped bikes did not have voltage regulation, simply relied on the rectifier and the bloody big battery for buffering.  Still use this system on my DMC-equipped 3C for simplicity.  Need to keep the lights on constantly to avoid cooking the 14Ah battery though.

HTH,
piet
 
Thanks Piet, that's good info.

The bike in question is not mine, so I'm trying to clarify things just out of curiosity. A friend of mine has already cooked, as you put it, one lithium battery. There was no problem with earlier standard lead-batteries. So it seems the wiring requires some modification in order to keep the lithium battery alive as it is more prone to over charging. Any ideas?
 
cape said:
Thanks Piet, that's good info.

The bike in question is not mine, so I'm trying to clarify things just out of curiosity. A friend of mine has already cooked, as you put it, one lithium battery. There was no problem with earlier standard led-batteries. So it seems the wiring requires some modification in order to keep the lithium battery alive as it is more prone to over charging. Any ideas?
Click to expand...

I fitted an Electrex regulator / rectifier in place of the simple rectifier that was in place on my 3C. Seems to work OK. And I have a DMC ignition on it.

I'm now running a Motobatt battery and the charging voltage is pretty happy at around 13.5 to 14 DCV whatever the RPM.

Before I fitted the Electrex unit it was going to 16/17/18 DCV (eeeeek!)

The wiring is pretty easy to work out, assuming you don't want a charging light on the instruments(!).

Let me know if you want more info.

H.



 
Last gel battery that I used lasted about 7 years, lots of track days in that time without using the lights.  Lead batteries generally lasted 2 years max.  Don't have a clue how a lithium battery would stand the abuse.

I'm looking into replacing the heavy gel item with a lithium, guess the required R/R will take up a little of the battery weight saving. :D

piet
 
Thanks guys.

So it seems the solution is pretty straightforward, just need to replace the rectifier with a voltage regulator...

Harry, what is the specific Electrex regulator/rectifier model you used? Also if you have the wiring schema, please send it to cape@laverdafinland.org

Thanks,
-Sami
 
cape said:
Thanks guys.

So it seems the solution is pretty straightforward, just need to replace the rectifier with a voltage regulator...

Harry, what is the specific Electrex regulator/rectifier model you used? Also if you have the wiring schema, please send it to cape@laverdafinland.org

Thanks,
-Sami
Click to expand...

It was the RR60 - this one http://www.electrexworld.co.uk/acatalog/RR60.html

The wiring diagram is pretty simple - 2 x Yellow wires, 1 x black and 1 x red. The two yellow wires you connect to the alternator output. The red wire is (I think) the +ve DC output and the black is the -ve DC output. ( I'll check the exact wiring tomorrow).

Job done.............

Other people on the forum have used the RR51. http://www.electrexworld.co.uk/acatalog/RR51.html - I'm not sure why - maybe they've got the charge light working or something?

H.
 
You must log in or register to reply here.
Back
Top