cdi compatibility

[nastyjones]

Trying to diagnose my buddys no spark issue. Will the cdi from my 85 gs 750 work in his 84 gs450 to try?

[tom203]

Trying to diagnose my buddys no spark issue. Will the cdi from my 85 gs 750 work in his 84 gs450 to try?

Hopefully, you checked/cleaned all connections on his ignition circuit. I'd avoid throwing a different ignitor box at it. Have you tried firing the coils manually?

[Billy Ricks]

If you jump the wires that run to and from each signal generator and the plugs fire the ignitor is fine. Just use a piece of wire or a continuity test across the two wires to each generator. If it fires the signal generators themselves may be the culprit.

[pete]

I doubt it. I think the years you're looking at have electronic advance and the curve will be different.

Also, given what I've seen so far, the pickups of the 450's are different to every other GS...

I'd be doing every other test first before trying a different ignitor, they are very difficult to locate as working items.

[Nessism]

Trying to diagnose my buddys no spark issue. Will the cdi from my 85 gs 750 work in his 84 gs450 to try?

Edit: Pete posted while I was typing.

No, this won't fit. The '85 ignitor is for bikes without a spark advance unit, and the 450 uses an advance.

BTW, the parts in question are NOT a Capacitive Induction Ignition (CDI). They are an electronic ignition, but not of the CDI type.

[Steve]

... BTW, the parts in question are NOT a Capacitive Induction Ignition (CDI). They are an electronic ignition, but not of the CDI type.

Very true.

Because "electronics" are involved, everybody assumes that it's "CDI", like in the car world.

In fact, it's just a few transistors (and their driving circuits) that replace the points and momentarily open the circuit from the coil to create the spark at the plugs.

An automotive CDI unit will also replace the coil with its own high-voltage wizardry and yield a much larger spark than is commonly possible with a simple points-and-coil system.

Some CDI units are also MSD or Multiple Spark Discharge units, where they zap the plugs with several sparks to ensure that every molecule of gas has the opportunity to get burnt.

Alas, our humble GS ignitors don't have any of those wonderful enhancements, they merely switch the coil current to make a single spark.

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