CDI ignition head scratcher

[waterworks]

I'm trying to find the fault in an inverter generator, there is no spark, much testing of everything else says to me the ignition power winding is not charging the capacitor, its a 50 v - 2200uf cap, the wiring diagram says the winding is 27 v, on a pull start I'm getting 2-3 v, the trigger pulse is 0.2 v.


Can I disconnect the ignition power winding and replace it with a battery to charge the cap to see if I get a spark ?
If I do I will have found the fault.

 

[Alec_t]

Should the 27V winding produce an AC voltage or a DC one? If AC, then I doubt using a battery as suggested would work. Could a DC input harm that box of tricks with the indicators on it?

 

[debe]

Your voltages are about right for pullstart. I have the same type of generator, disconnect the kill switch & the oil level switch these are known problems with these generators. The ignition system is a CDI type.

 

[debe]

I found checking ignite power using a digital meter not all that good when cranking. Using an Analougue multimeter on AC mutch better & got 10V AC when cranking. You could possibly as a last resort try feeding 12V into the module as a CDI ignition system will have a rectifier in there as they use DC. These ar CRO pics of what is coming from the windings at crank speed. All wave forms are X 10 as that's what the probe was set at.

 

[waterworks]

It is a Kipor KG2000.

If my power winding and pulse generator are putting out enough power, and the ignition module is a new one, unlikely to be faulty, what voltage should I be getting at the ignition coil terminals ?

Ignition Switch, and low oil cut off are both isolated. All the ground connections to the engine block are sound.

 

[debe]

You should get 5V AC pulse readings on ignition coil primary using an analogue meter. Heres a picture using a capacitor across the coil ( if you don't use the capacitor you wont get a spark), & flashing 6V DC across it, you should get sparks on the plug if the coil is ok. .

 

[waterworks]

I'll try that, glad I found you debe, your a CDI genius.

Not sure I've still got an anologue meter though, I will have to have a rummage.

 

[debe]

The only reason I sugest an analoge meter, is fluctuating voltages are difficult to read with digital meters. I also tryd feeding the module with 12V DC to see if it would work but no luck. Also these test were done on a Kippor 2600 generator basicly the same as yours.

 

[waterworks]

Is the value of the cap in your test circuit important ? I may not be able to get the same value.

 

[debe]

Cap value of .22uf is good but don't go over .47uf.

 

[debe]

Contrary to what the workshop manual says that the module cant be tested. This is how ive set up to test the module & it works. For the Trigger pulse you can us an old reluctor distributor, one in the picture was a Toyota one free at a recycling yard. The other unit I made using parts out of an old Toyota dist driven by a 12V elecrtric motor set at 2500RPM. The power for the module was 12V AC.

 

[MarkySparky]

Contrary to what the workshop manual says that the module cant be tested. This is how ive set up to test the module & it works. For the Trigger pulse you can us an old reluctor distributor, one in the picture was a Toyota one free at a recycling yard. The other unit I made using parts out of an old Toyota dist driven by a 12V elecrtric motor set at 2500RPM. The power for the module was 12V AC.View attachment 28255 View attachment 28256 View attachment 28257 View attachment 28258 View attachment 28259

Very cool clear case scope. Where can I get one?

Also, I’m filling this thread - I’m trying to make a CDI too

 

[Bluejets]

Very cool clear case scope. Where can I get one?

One has to read the fine print....DSO138.....

https://www.ebay.com.au/itm/264480362811