Is my 1980 Jota a BTZ bike ?

TheWrongTrousers

TheWrongTrousers

Senior member
Location
South London
How I can tell ?

The frame number puts it in the category of bikes that should have a BTZ ignition. However, there is something which I understand to be inconsistent with it being a BTZ bike. The red alternator charge light comes on at low revs and goes out at higher RPM.  This makes me wonder if it can be a BTZ bike because I am led to believe that the alternator light was not connected on BTZ bikes.

Can someone tell me a sure fire way of finding out whether this bike is BTZ or not ?

Thanks all.
 
Certain BTZ bikes had the red generator light working.
My 1979 Jota for example.

Take the tank off and see what type of coils are there.  If there is a grey metal box with 3 tiny coils attached then it is a CDI system.
If there are 2 big coils (one single, one double output) then it is  BTZ system, assuming of course everything is standard.
Also under the sidepanels should  be 2 ignition boxes if using BTZ system.

Aftermarket could be Boyer Bransden, Witt DMC, Sachse, Ignitech and no doubt a few more. Some use original coils, some replace the whole system.

What is it that makes you think it is inconsistent with being a BTZ bike?
 
2 fuses or 4?
Rats nest of spade connectors in the headlight or multipin plugs?

If the latter, it is/was a BTZ bike.  Most will have had the ignition changed by now anyways, but the wiring harness is totally different.
 
By and large i have multi pin plugs in the headlight. I also have two big coils one singe output and one double. I don't think i would easily recognise an ignition box.  It all rather points to it being BTZ.

Someone once told me that on a BTZ the alternator light was never connected to anything, so with that in mind I began to wonder what it was that i have got. I have experienced some strange charging problems lately with unexpected loss of battery power, therefore i have been thinking about what charging system I had. I  may have solved my problem by taking out the platform that mounts all the components and giving everything in sight (earths especially) a thorough clean up for the first time in 30 years. First time ever, probably.  I will see how it goes. If i still have issues,no doubt i will be back here bending your collective ear.
 
What year is the bike?
As I said some had the generator light connected, my 79 did.
 
The bike is 1980, frame number 7145.  It also has 4 fuses. Seems like a BTZ bike.

By the way, for future reference I would like to be able to identify the individual electrical components on the platform thing that bolts onto the frame. Is there any illustration/photo that anyone has that might help ?
 
If you are talking about aluminium boxes with a yellow Bosch sticker on them and there are two on your bike, these are the ignition modules one fires the center cylinder the other fires the outer cylinders.
 
Thanks Grant, and thanks everyone. Sorry to be so ignorant about this, its just that nothing electrical has ever gone wrong before, so there was no reason to give it any thought for the last 30 years.
 
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