# Help with project ??

#### Scovelli

Joined Sep 20, 2006
4
I have a project I'm working on and I wonder if there are any experts/semi experts out there that could look at a schematic from the 60's and see if it could be improved or updated. It's a vintage motorcycle CDI circuit.
I am going to be putting a few of them together and am curious to know if there is a better way or just go with the current design.

The schematic is here and the red boxed items are external of the CDI unit.

http://www.geocities.com/scullyh2@sbcglobal.net/untitled.JPG

#### beenthere

Joined Apr 20, 2004
15,819
Hi,

Not to pass judgement on your design, but I ran a Heathkit CDI on my car in the 60's. It worked fine. Yours appears reasonably robust. I'd stay with it. The one illustrated looks like all the parts are still available, t00. That should be a good reason to stay with it.

It is possible that something much more up-to-date could be designed. It might also be like gilding the lilly - what's the point?

#### Scovelli

Joined Sep 20, 2006
4
Hi there,
Thanks for the reply. I have several of these units that have negative function for some reason or another. Even if they test good on the bench, it's no guarantee they work in the real world.
I was just being inquizitive as to if there were newer better components to use. I was figuring that it would be a moot point, but thought I'd ask.
A side note: The schematic circuit is actually 4 individual boxes/units. They can still be purchased from the manufacturer, but at a rediculous $1550 usd. Approx$400 a unit. ??@#$%#$%??? Figure that one out !!!

I will go ahead with the schematic and thank you for your time and input.

#### pebe

Joined Oct 11, 2004
626
Out of curiosity, does 'have negative function' mean they are faulty?

#### Scovelli

Joined Sep 20, 2006
4
Sorry for that, yes negative function = no spark where needed.

#### beenthere

Joined Apr 20, 2004
15,819
Hi,

The price is outrageous! Aside from the pickup coils, there's hardly \$50 worth of components in that thing.

Frankly, since I got to quit adjusting ignition points, I have no idea how a modern ignition system works. I don't think any are capacitor discharge - but who cares? They work very well. But I'd sure want to look into some kind of replacement for that overpriced CDI system. And let the mfr know about it...