modified cdi and cr 80 coil

That's what we're saying - but we need pics of the guts of one to be able to replicate it. I've ID'd half the parts, but I need better pics to both verify and get the rest of the resistors and diodes, capacitor and thermistor.
 
rohmell said:
The diodes are probably all 1N4007

The resistor labelled 170K , first band is yellow(4), so should be 470K, although 3rd band looks brown to me (470 ohm)

Resistor next to SCR (brown black red) is 1K
Brown black gold resistor (7 o'clock from SCR) is 1 ohm
Click to expand...

Thanks Rohmell - I'll edit and update the pic. My eyes are so bad, I have to keep my resistors in labeled bags. xD
 
Wow, I fail. I was reading them backwards like a dummy. Here it is with updated resistor codes.

cdiboa10.jpg
 
I think you're right on that one rohmell. Sure looks blue to me, but green adds up better. :D

Of course, these pics were taken to show jumpers and headers, not to read components. I'd still really like to see some even more high res pics.
 
Like I said, my eyes are bad, and these pics suck. xD

I'm going both off a printed page and a full screen here, and can't hardly read half of the bands.

Not a problem at all - it helps to have a visual progress bar so we know what we've got left to do. Though you're probably right about the diodes, I do want to hold off on labeling them until we're positive. I'm glad you've jumped on board with this one Rohmell - it helps a lot!

Editadd:

Actually though, wanna take a second look at the 220/22k? Last band looks orange on both screen and page.
 
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I have one of these kits...I need a larger (or more) magnets for the dwell timing, & I need to replace the zeener for a litle higher voltage (& look up the transistor to see if it will work at my LiPo battery total loss system I bought it for)

Mostly I am curious if we could make the timing advance/retard with the cap specs.

I can change & test components but I am ellectarded when it comes to circute design. (i'll hack all day long LOL)

I am totaly open source if we can design our own for a few bucks....I would even etch the boards for a batch if guys wanted to build one.....any one wanna team up?
 
Hi, this is my first post, so hello all, nice forum lots of great info.

I've been following this thread and have been designing a PCB with ExpressPCB, neat program and its free. I've completed the KDX CDI schematic and my first shot at a PCB. But I'm no expert just a hobbyist who acquired a bike with a dead CDI, After seeing some of the schematics offered by rohmell, I'd now like to incorporate a resister pot to be able to fine tune along with a possibly external thermistor to monitor engine temp and adjust timing and have jumpers or switches to activate these extra features.

I have attached my work in a a ZIP file.
 

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Thanks for the feedback, I fixed the double STR+ typo, and created a new file(CDI-2-Trim pot) keeping in mind your input on having the COIL+ trace as short as short as possible. This one has a potentiometer to trim the spark advance based on Rohmel's supplied diagram. This will just have a straight timing curve as I dont have the high RPM spark retard circuit and its extra caps, I'd love input on adding that and a thermistor to alter timing based on engine temp. I think I will build this simple circuit first and then try and get fancy.
 

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if you can figure out a temp guage for the bike i would maybe be interested in buying one from you. good luck on it..your way smarter then me, haha.
 
A temp gauge is simple stuff - I could pull the one I have on my PC off right now and throw it on the bike. You'd just want to bolt to one of the fins in the front of the jug or head.
 
I agree a temp gauge would be pretty simple, Im sure there is something you could buy off the shelf for that application. I want to adjust timing based on temp like the KDX CDI does only have it tailored to our engines and even make it adjustable so you can tune the CDI to match aftermarket parts such as heads pistons and cylinders which may allow more timing advance than a bone stock engine. I just bought a bunch of parts, and instead of the prototype board they seem to use in the $75 CDI kit, I'm going to be etching my final board on a single sided PCB. So my end product should be more rugged and look a bit more professional. I will keep you all updated, also any suggestions for other features would be great, I was thinking of including a half wave rectifier to charge a battery off the white wire, or even having the ignition system powered by a battery, but after reading some threads it seems 3 watts is all you can really get off the white wire's coil so I don't think its worth it. I also wanted to say thanks to all here, I might have some basic electrical knowledge but thanks to forums like these I'm learning more and more, I can draw a CDI schematic from memory now, couldn't say that last week hehe.
 
headtrama said:
It smoothed out the vibrations for sure . You get to run a real coil that's a plus . And you have four timing curves to choose from . I have done a lot of work to my motor besides the Cdi box , I built a pipe for it cleaned up the ports and changed the head the bike has picked up some mph and runs real good with no four stroking at all . The only thing left is for it to blow up now lol .
Click to expand...

How I chose a different timing curve?
 
Do you have a schematic for that unit? Maybe can be modified for use with the MB engines.
Click to expand...

I can sketch it up when i get a minute (absolutly burried in work for a few days).

Exciting stuff going on in this thread...
 
Scootershack said:
if you can figure out a temp guage for the bike i would maybe be interested in buying one from you. good luck on it..your way smarter then me, haha.
Click to expand...

The temp gauge from Pistonbikes and treatland.tv have enough wire so you can mount it on the handlebars.
Pistonbikes has some temp gauge for sale TTO - Temp Gauge

treatland.tv but their out of stock trail tech digital temperature gauge

I use a traxxis temp gauge for radio control cars Traxxas Part I just wrap the cord around the spark plug. It was running hot one day when I was going up a hill and read 390 degrees. I can only take a reading right after I shut down the engine. If the temp gauge is on, theres alot of interference and cannot take a reading. I dont know what the max temp reading is.

You can also use Venom Venom Racing VTM Micro On-Board Temperature Monitor (Green)
 

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