New Tri-Spark Classic Twin Electronic Ignition

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Nov 20, 2004
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I expect many members will have heard of Tri-Spark digital electronic ignitions which were originally developed by Steve Kelly in Australia for the Triumph & BSA triples, and later on, a twin cylinder version was introduced for Triumph/BSA/Norton twins.

Now there is a new 'Classic Twin' ignition system available from Tri-Spark, and this new system has no amplifier box, the whole thing is contained within the points housing.

If anyone has tried, or intends to try one of these new Classic Twin units, then I hope they will be able to tell us what they think of it?
I have the old style trispark not yet installed on my MK11 850.
Steve kelly is saying the new Classic Twin unit needs 6volt coils to operate and He seems to think My 73 Norton has 12volt coils. I will have to check them out as He seems willing to allow me to change over to the new style if coils are correct voltage! it will be a lot less hassel to install.

At what dates or models did Norton change from 6 to 12 volt coils?
dgwilson said:
At what dates or models did Norton change from 6 to 12 volt coils?

They didn't, they changed from 12V coils to 6V coils (plus a ballast resistor) from 1971-on.

But anything could have been changed?

To check what voltage coils you have, look on their bases, if they are Lucas, then they should be stamped 17M12 (12V) or 17M6 (6V). If they have been replaced with PVL coils then they may be stamped = 6V or 12V.
L.A.B. I am real tempted to try the new Tri-Spark. This would be my first time to do electronic ignition in any British bike. I have an early 850. From what you read and all, what do you think? Does this new Tri-Spark look like it should be pretty good?
Yellow_Cad said:
Does this new Tri-Spark look like it should be pretty good?

If Steve Kelly has done as good a job with this new system as he did with his previous Tri-Sparks then I think it should be good.

As it is a self contained unit, I would expect it is easy to fit, and if you do get into difficulty, then I'm sure Steve would be happy to try and help you.

GavinJuice said:
is this new system going to replace the old style box?


GavinJuice said:
are there any disadvantages to this?

The boxless points housing unit isn't really a new idea. The downside of that type of unit as far as I am aware, is that the electronics can't really be isolated from the engine heat and vibration as well as they would be in a separate box mounted well away from the engine, so I don't know what sort of life-expectancy the Classic Twin system will have?
Hopefully Steve will have taken steps to ensure these units will be reliable when used under those conditions?

And I have invited Steve Kelly to comment on his new Classic Twin system here, if he wishes to do so?

[Edit] See his reply here:
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