CDI repair questions

I pulled apart the CDI on my yz80 when I was 12, soaked it in paint thinners to soften the glue they dunked it in and scraped it away then I tried to draw the circuit from looking at the board and components

eventually just started changing the main bits, bigger capacitors, new diodes and a new three legged thingy

it worked in the end but the main problem was the source coil

can you get an aftermarket programable cdi? or maybe a circuit for one so you can change the curve, I'd like one of those.

RE: Re: RE: CDI repair questions

Hey wictor.nice dud job but you should know that your ignition trigger coil gives two adjacent signals 60degree apart from each other because the flywheel has two magnets for triggering.I recommend you be using a hall effect sensor for ignition trigger for your next digital cdi unit. try replacing the scr and zener diode and other diodes on your current sem ignition module.post here a pic of your opened sem module.

Unpotting, not plants

I had this SEM Ignition module (CDI) fail a month or so ago after running it with an Electex stator on a ktm for a couple of years. I've replaced it with a new CDI and I've just had my old genuine stator rewound by Bradford ignitions in spain, so hopefully it the new cdi should last ok

I've spent a week or two unpotting the failed one just to have a look, when it failed my bike started to loose top end power and then refused to start when I stopped it. When investigating problem there was only a very weak spark so I was thinking this might be the capacitor? This all went down hill within a matter of ten minutes, it now starts better than it has ever done with the new module.







I thought some of the very clever members on this very good forum might be interested in seeing the bare item
I could identify some of the compents and numbers on them if your interested, I might try repairing it for a spare if I ever have some spare time and can get the spares. The main capacitor is 68micro F 400v but it doesn't say if ac or dc on voltage rating.

The small component between the diodes broke as I was removing the potting, it was blue and probably a zenor diode. Does anyone know the exact spec of this and its direction? I'm not an expert in electronics

The small square blue item at the top left of board has no markings but looks like another capacitor?

probably our best mind here for electrics is the greek 'OYK'. try dropping him a line.

regards

Taffy