Suzuki TS185/TS250 CDI Box Replication [Update](Again)

[mikerj]

I thought R1's value and location look weird, ahhh "it doesn't work!" kind of fix but at the expense of kick- start harder faster, lol. Big difference in easier kick-start (triggering) with it at 1k but I could not find the consequence.

To dampen ringing from the pick-up coil due to the reverse-recovery time of diode D4, or limit the big SCR's gate pulse current, I'm not sure what the low value is trying to do and can only guess at the magnetics.

Maybe it just provides a DC path to ensure C1 gets discharged?

[jeffheath]

[Update] The boards came in, and I have populated one and tested it on the bike. So far, it seems to work just fine.

[jeffheath]

Another update, I have designed a case in rhino, and had it 3d printed. The company that printed it didn't do a very good job, (they didn't know how to print the top, so they just glued a piece on) but it was cheap, and the rest of it seemed ok. I'll try different companies. I also found original style connectors and sleeving that are still being made today from a store called "vintage connections", so I'll probably post an update once I get it wired and potted.

[MoM]

I’m following this thread with great interest. Thank You - Mike

[jeffheath]

Another update, I've been riding the crap out of bike, and the ignition seems fine (not one backfire on shutdown) I've gotten the bike up to 70, (mph) which is fast for a piston port ts185. (Sorry, no fancy dyno tests ) The case I had printed turned out to be a dud (it was way too big) but maybe someone can work from the file I posted. Basically, my bike is doing fine, and because of that I have lost steam on completing a "full" cdi unit, but I feel as though the job is done, and this thread will be here for anyone who needs to build one. (And I will be here to make sure the files stay uploaded)
If anyone wants to link to this post on other (bike) forums, be my guest. I may go back and redesign the circuit board to be smaller, (this was the reason the case was so big) but the layout of the board is not important, and anyone who uses kicad could probably do a better job than I did. Anyways, If anyone wants to make the board smaller, make a good case, and wire and pot these, then they could probably sell them, otherwise I'll be here to help anyone that doesn't want to pay so much for cdi unit that could be up 47 years old!

[yepp]

Hello Jeff

I hope you pick this up, any chance I could ask you a few questions with respect to your CDI unit?

I have 2 Suzuki TS250As and a TS185M and I'm keen to explore the possibility of new CDI units.

Thank you for your time

Best regards

Martin

[stev]

can anyone tell me the voltage output of the generaton coils for the cdi init on a TS 185  1778
thanks

[floobydust]

It depends on engine RPM, it's not a sine-wave or DC. It's complicated.
I would say around 400V and design for 600V (SCR, cap, diodes)