Roll Your Own CDI

Are You Going to Roll Your Own CDI?

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e616, got new cdi in installed ran stopped all signs point to bad magneto, lord knows every time I got killer voltage from the homemade one then not the magneto was inconsistent. Probably had 3 good CDI's lol. Live and learn.
 
Hi everyone, one my first bike an trying to find a way to a get the little rocket to run better at top end AND wait for it, find a way to get the magneto to produce enugh current for spak AND.. ( the good part) ALSO charge a 12 volt 1 amp batttery that is running led head lights, indicators tail light ( yep alrwady got the flasher unit to run LED indicators,) and horn.
Can anyone share their wealth of knowledge and trail and error wisdome please.

A responce here is cool as is to my email
 
Hi, just so u know, the lighting coil on these Chinagirls is a 6 volt coil, & at quite low current. It is possible to charge a 12 volt battery of it tho, u will need to use a rectifier & voltage amplifier. Cheers
 
I am still a bit puzzled and inexperienced with these motorcycle coils.
Is the solid metal part sticking out both ends bolt holes or bolt holes/negative wire post?
Where do the other wires hook to?

Would these work fine, these fit within my budget whereas I really have no budget at all and bills to pay and mortgage etc. life sucks sometimes, bleh!

Here
And Here
 
Hi Toadmund, if there is only 1 terminal or wire on the coil (besides the plug lead), then the earth connection (black magneto wire) goes to the iron core that u ask about, as well as the CDI u r using. If the coil has 2 terminals or leads other than the plug lead, 1 will be the earth, tho it probably would still be internally connected to the iron core. Cheers
 
ivan H said:
Hi Toadmund, if there is only 1 terminal or wire on the coil (besides the plug lead), then the earth connection (black magneto wire) goes to the iron core that u ask about, as well as the CDI u r using. If the coil has 2 terminals or leads other than the plug lead, 1 will be the earth, tho it probably would still be internally connected to the iron core. Cheers
Click to expand...
Like this then?
 

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Thats it, spot on. Its best to hook it up like that using wire & an electrial eye connector rather than just using the connection to the frame,,, u can get bad connection between motor & frame or coil & frame. This way u know u have all good connections. Cheers
 
Hey, thanks a lot, you daved (er saved) me a lot of interweb searching, I placed a bid on one of those coils.
Now, I'll keep my eyes peeled for a nice housing box for my retard circuit CDI, the one that rohmell has in photobucket account.

What ever happened to rohmell? I feel like I missed something important, I came too late, like a hippy missing Woodstock.
 
goto Jameco electronics ,they have plastic enclosures the same exact size and bigger than the original jag I just ordered some for my projects .box lid and screw $4.59 each also they will send you a free catalog in the mail off all their stuff . Peace, HD
 
But before I buy enclosures, I wonder if anybody can verify something for me.

It's rohmell's retard circuit, something tells me the electrolytic capacitors bias is the wrong way.
Can anyone confirm this?

Here is rohmells pictorial:
boardlayoutwithretard.jpg

Here's his circuit diagram without the retard addition:
rohmellcdischem.jpg

And here is the circuit diagram with the electrolytic capacitor and resistor that I added in:
(See attachment)
 

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OK, I may understand a bit better, when the negative pulse from the coil is off, the SCR diverts the positive pulse down toward the electrolytic cap, otherwise the resistor parallel to the E cap absorbs the negative pulse.

Yes?
 
Hmmm, this is becoming a lonely thread.

Anyway, I finally finished my CDI unit, the simpler one with the retard function.
And I just got my Ignition Coil in the mail yesterday, it cost me 10 bux on fleebay.
Now I just got to check it over again for the 'nth' or 'eth' time, then I'll put it on my bike.
Now, I'll have to make the jag clone sometime soon.

Here are some pics:
 

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Toadmund said:
Hmmm, this is becoming a lonely thread.

Anyway, I finally finished my CDI unit, the simpler one with the retard function.
And I just got my Ignition Coil in the mail yesterday, it cost me 10 bux on fleebay.
Now I just got to check it over again for the 'nth' or 'eth' time, then I'll put it on my bike.
Now, I'll have to make the jag clone sometime soon.

Here are some pics:
Click to expand...

Does it look like you can remove the plug wire from that coil easily enough to replace with automotive wire? Reason being, once upon a time I was ready to build my own CDI, ordered parts and everything. When I got the coil (different from yours) it was the type where the wire would rotate at the coil, didn't seem like it would come out well to be replaced. My bike frame is so small that I NEED to use a rubber automotive plug boot cause there isn't enough clearance to seat a plastic one (like on the coil I ordered or the coil you picture) Since my bike runs pretty good on the stock CDI and I haven't had an issue in about 2,500 miles with it I kinda lost interest in the project, but it would be kool to get a DIY CDI put together eventually...
Sorry to be long winded about it, if somebody knows a good coil that works and can have the wire replaced I would be interested in the info.......
thanks
 
Is yours a straight or slant plug? I have no room either, if I want to remove the head, or head and cylinder, the motor has to mostly come off, but I have no issues with my plug boot.

I would tell you about the plug wire but I am not about to find out how removable it is unless I absolutely have to, just in case it alters the structural integrity of the unit.
It may fall apart just as well on its own anyway!
 
Toadmund said:
Is yours a straight or slant plug? I have no room either, if I want to remove the head, or head and cylinder, the motor has to mostly come off, but I have no issues with my plug boot.

I would tell you about the plug wire but I am not about to find out how removable it is unless I absolutely have to, just in case it alters the structural integrity of the unit.
It may fall apart just as well on its own anyway!
Click to expand...

Is the wire solid in its connection to the coil or does it rotate?
 
It doesn't move,..... well it did, but I tightened it back up again, so I assume it screws out just like the stock one.
I saw the same one up for bid if you want the link.
 
Toadmund said:
It doesn't move,..... well it did, but I tightened it back up again, so I assume it screws out just like the stock one.
I saw the same one up for bid if you want the link.
Click to expand...

Yah, if it seems the wire goes in similar to the stock CDI then I would be interested in the link... Thanks....
 
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