modified cdi and cr 80 coil

I built my CDI, and mounted most components, I'm still unsure on a the resisters. When I first tried the CDI on the bike I got nothing, no spark, so I pulled (D4) and (R1) and set the pot to 18 and 82ohms and she fired up and I got to ride my bike for the first time under gas power, but then it died after only going half way around my block. I fiddled with the pot, tightened my connections and pulled the plug out. I pushed the bike with the clutch dumped and eventually I got spark again. Went for another short ride then again lost spark, and now I can't get it back. I checked I am getting voltage on the blue wire and even the red wire to the coil. I might also try adding one more capacitor I could not get a 2.0uf 250V polypropylene I had to use 4 0.47uf caps in parallel so I only have around 1.8uf as tested on my meter.
I'm using a 6volt coil from a 79 dodge I had laying around.

I have attached my latest .pcb file

Note: The jumper for the caps is the only one installed and again D4 and R1 are pulled
 

Attachments

hi, i found this details.
scaled.php

im not sure, but for me te conection of these resistors is
scaled.php


Greetings friends, and that will not freeze the postauflg
 
disculpa, no me di cuenta, aca las cuelgo de vuelta con mejor tamaño
(sorry, I did not realize, here I back with the best size)

cdiboardcopia.jpg

wiredcdiboard12.jpg

for me there are 2 resistors between the capacitors

regards
 
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I will try to find some higher voltage caps, I know my SCR is only rated for 400V as I could not get the 600V that was spec'd in jaguars build, jaguar also spec's 250V for the cap, either metalized polyester or metalized polypropylene which is supposed to be better for this application and is what I got. I tested my caps and they still measure 1.8uf, if they had failed would I still be getting this reading? Would the SCR fail in a wierd way working for a short time than dying than working some more?

I'm planning on removing the pot and installing 18 and 82 ohm resisters to keep it simpler while testing, and adding 1 more cap.

Yes the '79 dodge was 12 volt but the coil used a ballast resister to drop the 12v down to 6v, the coil is kinda big but i will eventually get a motorbike coil when its all working. Is there an ideal primary winding resistance, or can the CDI be matched to a coil, It would be neat to make a Coil On Plug setup, as I have a few, but they are 12v coils.

The weirdest thing is that it only runs for short bursts like there is something heating up or coming loose from the vibrations. I bet it will work when i try it tomorrow, its really frustrating to be so close and being such a simple machine there are not to many options the fix must be something simple.

I will take some pics of my setup, my CDI box really turned well now I just have to make it work well.

Thanks again to the people on this forum I could not have done it without you as a resource.
 
sorry rohmell i dont see blue wire, i only see black, red and green wires ;)

i cant indentify the value of these resistor, because i dont have one of these cdis to take a photo :(

anyone can take a photo of the pcb of other angle?, or underside?

saludos gente, y que no caiga el post
 
No one is even talking about marketing anything, if they were it'd have been moved to our 'Swap and Shop' section as per our rules: http://motorbicycling.com/f21/please-read-these-simple-rules-2.html

This forum is specifically for our members to discuss any and all topics relating to motorized bicycles, including the specifics of any and all products purchased.

You may wish to read: http://motorbicycling.com/f21/attention-vendors-8015.html specifically;

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rohmell said:
The stock black box contains a CDI and an ignition coil, all potted together so that you can't see the circuit, make repairs or modifications.

The CDI is just the portion that takes the engine's magneto output, charges up a capacitor, then at the right time, discharges that capacitor, into an ignition coil.
Click to expand...

thinking of putting a 1uF instead of the normal 2uF in mine to see how she goes :)
 
rohmell said:
1uF will work fine. Since it is smaller it will charge faster, and you can attain higher RPMs. But, since it is smaller, the discharge pulse to the ignition coil will be smaller, but probably will be unnoticeable.
Click to expand...

I was thinking that.

i went and bought a 1uF 450v capacitor :)

but it's polarized :S

ok i tried to open the CDI box and no luck look what happened :(
 

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well no luck anyways the damn CDI box is filled solid.

just want a simple diagram where i can get a nice CDI going after i go to the electronic store to get the parts
 
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