Cheap CDI

[skrew37]

UPDATE:
Bad news. While removing the plastic plug casing to expose more of the pins to solder jumpers to, I accidentally snapped off a pin. Since the whole thing is filled with epoxy, it's impossible to even dig it away to expose enough of the pin to solder to. This might be a good sign to follow more experienced people's work on these...

 

[rustycase]

Do you have a dremel tool so you can grind away at enough of the epoxy so you can solder a lead onto what was running to the pin?

Good luck
rc

 

[skrew37]

I tried that. Then I started nipping away at the case itself and found nothing. It was a lost cause and a waste of $6 on my part. I couldn't find the wiring harness I needed as soon as I wanted it and rushed things. I hate ruining things that could have been something. Oh well, c'est la vie...

 

[rohmell]

Some potting compounds can be softened with MEK. If you have some lying around, you could let the CDI soak for a while in some MEK.

I would mention DMSO, but I won't, that stuff will eff you up.

 

[skrew37]

I don't have any of that lying around unfortunately. Maybe I'll keep chipping and gnawing away at it until I find something recognizable. I'll definitely have to excavate the components.

 

[skrew37]

Ok. Round 2. I decided to give it another try before I build my own CDI. I bought a cheap racing CDI that looks almost identical to the JN Motors unit. How do I hook this up? I'll be using a CR80 iginition coil with it as well. It has 5 wires which are all red and black...Any help?

 

[DuctTapedGoat]

One of those is orange, not red. That's the one that'll go to the coil Orange = fire, black = ground.

 

[skrew37]

Ok thanks. So the orange and black go to the positive and negative (respectively)on the coil, the black wire on the left in the pic is ground? and the other 2 go to the black and blue wires from the engine? Obviously I'm guessing here...

 

[rustycase]

What a nice looking cdi, skrew!
probably better looking than most could build at home.
As DTG said, there's an orange, a red with a stripe, and one of the blacks is paired with another wire.
Seller really has a responsibility to provide you with a diagram, IMO.
Otherwise, 'Thevenin's Theorem' it is, for reverse engineering.

What was your source?

I'll look forward to seeing your running results posted!
Best
rc

 

[DuctTapedGoat]

Well, no.

I would do this personally.

Orange/Black - To Coil.
Black Motor - Black CDI.
Blue Motor - x1 Red CDI.
White Motor - Wire Cap.
x1 Red CDI - Wire Cap.


Please, if anyone knows why this isn't a good way to wire, speak up. Seems to me this is how I would try though.

Note though, you could prolly wire a tachometer to the other red wire no problem at all.

 

[skrew37]

OK. Like this?

 

[DuctTapedGoat]

I would say correct, but I can't be sure I'M correct, but yes, that's what I would try.

 

[skrew37]

What a nice looking cdi, skrew!
probably better looking than most could build at home.
As DTG said, there's an orange, a red with a stripe, and one of the blacks is paired with another wire.
Seller really has a responsibility to provide you with a diagram, IMO.
Otherwise, 'Thevenin's Theorem' it is, for reverse engineering.

What was your source?

I'll look forward to seeing your running results posted!
Best
rc

I got it here:
2 STROKE RACE CDI IGNITION JOG Minarelli 1PE40QMB | eBay
There are 5 left.

 

[skrew37]

What kind of tachometer do you think I should look for if I choose to try to run one?

 

[DuctTapedGoat]

Something like a Dwell Tachometer/Volt Analyzer. HF has them all day long.

 

[skrew37]

Thanks. I'll look in to it.

 

[skrew37]

I received an email from the merchant with the wiring diagram. I'm still a little foggy on the connections, keep in mind I'm still learning. Here's what they sent:

 

[DuctTapedGoat]

Blue from motor goes to EXT.
Coil goes to IGN.
Kill switch goes to SW.
Black from motor (Ground) goes to E.

It shows PC going to ground, but I would cap it and leave it alone.

 

[skrew37]

Thanks! Now I just have to wait till it gets here. In the meantime, I need to check for some air leaks and build a new tank bracket which snapped from vibrations this weekend. Maybe I'll use steel instead of the aluminum strip I had laying around.

 

[DuctTapedGoat]

You're welcome - now of course, that's just after a 30 second glance at the attachments you posted, I could be wrong, but it seems to add up.