modified cdi and cr 80 coil

[Lazy Dog]

Find a pic of the bottom side and then we can figure out the schematic.

The Jag CDI is epoxied in the project box. I've been using one for since last summer with zero issues. It works great. (did expect the price to lower by now)

I would think a Potentiometer would actually be kinda useless, I'd be a little worried of it getting readjusted, and with jumpers or dip switches at least you know what timing your running, any kind of dial would still leave you guessing. Since the CDI is pretty much a set/tune and forget kinda thing, seems piontless.

The Jag unit I have came with 3 jumpers, the new one is A2 just above the A jumper. It cuts the the over all timing in half, So really there are 8 timing options.

Crap all I was trying to say is that I'm centralizing all the electronics into a new housing. I will be ripping my jag box open sat evening after a ride. I can identify everything on there then if you still need and maybe even get a pic of the back for you guys if you still need it.

 

[Lazy Dog]

are these the pics your wanting posted

 

[ivan H]

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hi Lazydog, the schematic you posted is what I used as a starting point. Notice that the international model uses a 27 ohm pulldown resistor, not a 16 ohm. Charge cap is changed to 1uf to accomodate the china girls weaker stator. Cheers

 

[headtrama]

Posting this for Ivan H

 

[fonzie]

There is a Jaguar unit in the swap section for $35.

 

[ivan H]

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Hi guys. Ok, note the 27 ohm pulldown resistor. Jumper A put 120 ohm resistor in paralell with, bringing resistance down to approx 22 ohms, retarding timing by a few degrees. Feel free to experiment with 27 ohm, within reason. Increasing value advances timing & vice versa. To tell if its too advanced check plug. The sides of the center electrode should be entirely covered in oxides. If the very end 1/2mm or so shows bare metal its too advanced & the heat has burn the oxide off. Cheers

 

[ivan H]

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Hi, I shoulda posted this ages ago ok. The unit I first built that I said was fireing way retarded I have found actually had a faulty SCR so,,,. To make a unit like Lazy Dog says with 2 A jumpers, u could just add another 120 ohm resistor & jumper to be used in conjunction with the first A jumper, or add a 240 ohm & jumper & use either or both to give extra settings. Also, the 620 ohm resistor in the timing circuit can be changed to alter when the retard kicks in. Increasing its value will make it kick in earlier in the rpm range, so maybe a 760 ohm would be better for a chinagirl. I'll try it out and post results. Too c a better copy of the schematic, Rohmell posted a much more legible copy in his thread entitled "roll your own cdi", thank you Rohmell. Cheers

 

[multipaul]

Very intersting thread. I've read it completly from the first beginning. Well, after one year of hard work the J-CDI seems to be decoded sucessfully. In my opinion this is a great sucess of the members of this forum.

The only missing things are a timing light, perhaps a rpm counter and a truly fitting degree wheel. With the last position I could probably help you out.

Multipaul

 

[multipaul]

From the schematic, I can not properly detect which signal arrives at the gate. Could someone with an oscilloscope tell me the voltage and polarity?

Multipaul

 

[ivan H]

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Hi, the negative voltage comes from the negative half of the same AC voltage, that the positive half of charges the charge caps. They r rectified to do this. The negative half develops over the 620 ohm resistor in the R/C timing network. The scr condust when gate is a couple or few volts negative in respect to the kathode. Cheers

 

[multipaul]

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Hi, the negative voltage comes from the negative half of the same AC voltage, that the positive half of charges the charge caps. They r rectified to do this. The negative half develops over the 620 ohm resistor in the R/C timing network. The scr condust when gate is a couple or few volts negative Cheers

Thank you, Ivan. I can see clearly now.

Multipaul

 

[ivan H]

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no problem, glad 2 help. If a few people start building them & experimenting then posting results we should be able to figure out a really well performing reliable cdi with enought options available to cover all motors, from stock to wild.. Just a note, be sure to use the 250vac X2 type polypropylene charge caps, not the speaker crossover types. Cheers punters, enjoy

 

[ivan H]

also, I still havent learned to post photo,s off my phone, but I can email someone photo's of both sides of my cdi so they could post for everyone to see how I have laid components out & the tracks on the back of the board. Cheers

 

[ivan H]

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Hi, the Rohmell redrawn schematic is on page 42 of the "Roll Your Own CDI" thread. Maybe someone that is computer able could lift it over here, as its much more legible, thankyou Rohmell. The 1 posted here I drew on paper & mailed 2 Headtrauma & asked him 2 post here,,, & I was "crissed as a picket" when I drew it, as u can c. Cheers

 

[Drewd]

I've read this thread and its hard to follow; a lot of postings don't reference what is being built. Can someone pinpoint me to a schematic for Jaguar's CDI box so I can make one myself? With the prices he and JNM are charging, they should have enough money in the bank to patent protect it. thanks!

 

[ivan H]

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Hi Drewd, go 2 page 17 of this thread. The 6th posting on that page is by Headtrauma. Its the schematic I snail mailled him & ask 2 post. 4 a better drawn 1 go 2 page 42 of roll ur own cdi, I asked Rohmell 2 redraw it. Its close enough 2 use & u can customize it further 2 ur liking. I've been running it 4,,, I'nt know, a long while now, maybe close 2 a year no problems. Also, someone recently emailed me thru this forum, needing 2 cure detonation occuring from using a very high comp head. I advised him the same as I've posted regarding changing resistance values to alter the timing in various ways. He emailed the other day & gave positive feedback, so if u do build & need advice just post or contact me thru the forum. Cheers

 

[ivan H]

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Also, I aint so sure Jaguar could patent protect, seeing as its already a knock off he might just run into a few,,, how would u say,,, obstacles. Cheers

 

[DaveC]

I've read this thread and its hard to follow; a lot of postings don't reference what is being built. Can someone pinpoint me to a schematic for Jaguar's CDI box so I can make one myself? With the prices he and JNM are charging, they should have enough money in the bank to patent protect it. thanks!

I think it's a Kawasaki box if I remember right with mods.

 

[Drewd]

Thanks everyone. I did buy a Jaguar CDI out of guilt and will use this info and wiring from the JAG CDI possess to build future ones for myself and not spend almost 90 dollars with shipping for another one.

 

[ivan H]

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Thats the 1 Dave C. Really, u could add as many jumpers as u like, or advance the timing, retard it, bring the point where it starts to retard forward or back, steepen or lessen the retard, change the kathode/gate relaationship. If u went to far, well I've already told how to tell if ur too advanced off ur plug, thats probly the only way u'd do harm, unless u retarded it so far u got it to run backwards, & even then it'd be a retarded fireing, so u could still change it back to where it was ok. Cheers