Chinese Kit CDI Reverse Engineering

GoldenMotor.com

Do You Find This Thread Useful and Informative?

  • NO, I will just keep buying a Chinese CDI when mine fails.

    Votes: 3 7.1%

  • Yes, I wanna build it!

    Votes: 39 92.9%
  • Total voters
    42
dakota47l1

dakota47l1

New Member
Oct 2, 2011
132
0
0
st louis mo.
.wee.
rohmell said:
I have one of those tube testers that could usually be found in larger drugstores, grocery stores, and in Radio Shack back in the olde days.

To the left you can see a big ole Tektronix tube scope, model 545A, and below the tube tester is another 545A, and yes, they are fully operational and calibrated.
Click to expand...
i remember those!! they where in every drug store when i was a kid...if you had a blown tube you could take it in and test it.
 
rohmell

rohmell

Active Member
Jun 2, 2010
1,531
6
38
New York
And if it wasn't a bad tube, then you had to call one of these guys to come to the house and fix your TV:
 
Ratchetbirds

Ratchetbirds

Member
Jun 12, 2011
125
1
16
Eastern Wash.
My German shepard trapped the TV repairman in the garage for 4 hours. We had to pay for that time. He was rather upset, I have no idea why. The repairman, not my dog.
 
rohmell

rohmell

Active Member
Jun 2, 2010
1,531
6
38
New York
I am going to breadboard and conduct further experiments on the Chinese CDI schematic.
I hope to have some pics maybe even videos, ready soon.
 
U

UVsaturated

New Member
May 15, 2008
140
4
0
Dayton, Ohio
Considering these units go bad and mine was probably due to wiring in the kill switch improperly (no instructions came with my kit on the correct wiring).

Do any of you know how to wire the kill switch properly? It looks like grounding the blue wire should do it. The white wire from the magneto, I am assuming, is voltage for accessories?
 
biknut

biknut

Well-Known Member
Sep 28, 2010
6,631
409
83
Dallas
UVsaturated said:
Considering these units go bad and mine was probably due to wiring in the kill switch improperly (no instructions came with my kit on the correct wiring).

Do any of you know how to wire the kill switch properly? It looks like grounding the blue wire should do it. The white wire from the magneto, I am assuming, is voltage for accessories?
Click to expand...
The 2 wires from the kill switch just parallel the blue and black wires.
 
rohmell

rohmell

Active Member
Jun 2, 2010
1,531
6
38
New York
CDI UPDATE:
Warm weather is here again in NY, and it's time to revisit the Chinese Kit CDI Reverse Engineering thread.
Currently consulting with a(n) R&D firm to re-engineer the Chinese CDI module, and discussions are to have it on a PCB, mounted in a box, no potting material is to be used, so that all components can be easily seen and identified, and can be repaired by the end-user if needed.
We might be winding our own custom ignition coil, too.
 
happycheapskate

happycheapskate

New Member
Nov 26, 2009
1,989
3
0
Rockwall TX
Great thread, but mine has worked fine a long time, and I think they are cheap. I'm done with grubees anyway. I like brushcutter and r/c motors way better.

I googled "what does CDI do" and got this.
http://wiki.answers.com/Q/What_does_a_CDI_unit_do

Maybe you can do better than just copy the chinese plastic CDIs. If someone on this board is a computer whiz or something, maybe they can build a better one, and ya'll can copy that. Since exact size isn't an issue, maybe they can find a way to get cheap components anyone could buy, and boards amateur soldering work can succeed on. You could get creative by sealing them inside plastic soapdish boxes, mint cans, snuff cans, etc.
 
Ratchetbirds

Ratchetbirds

Member
Jun 12, 2011
125
1
16
Eastern Wash.
happycheapskate said:
Great thread, but mine has worked fine a long time, and I think they are cheap. I'm done with grubees anyway. I like brushcutter and r/c motors way better.

I googled "what does CDI do" and got this.
http://wiki.answers.com/Q/What_does_a_CDI_unit_do

Maybe you can do better than just copy the chinese plastic CDIs.



First off, we are not just copying the China CDI. We are reverse engineering it to know exactly how it works. Once that is known, then improvements can be designed and made. You need to read the companion thred to this called "Roll your own CDI". We already have a "whiz-guy" working diligently on improvements to the chinese CDI. His name is Rohmell and with the help of many others here we now have a very good working basic CDI. It produces a much larger spark than the original. If your original is still working, then you are one of the lucky few.
Click to expand...
 
happycheapskate

happycheapskate

New Member
Nov 26, 2009
1,989
3
0
Rockwall TX
That's awesome. I am sad that there isn't a European or American version, with the bugs worked out of it. The China happytime kit is a great idea, but cuts some corners. It's good that people are making so many mods and aftermarket parts to fix them up right.

Yeah, I'm surprised it has lasted this long. I cracked the case a little when I built the bike, by tightening the little clamp that came with it. I superglued it back and threw the clamp away, and just double-taped it and zip tied it to the frame with about 4 or 5 zip ties, around the whole box, not through the ears/tabs. I also ran the kill switch to the white wire and grounded it to a water bottle bolt. I didn't ground the CDI for the killswitch. Maybe that is the difference.

I just replaced the stock boot. The stock boot "clamps" on the standard spark plug ball for a while, till the rubber degrades. It arcs to the ball tip, and after a while starts skipping. The stock type can grip the threads if you take the ball off. The instructions didn't mention that, so I'm sure a lot of people do like I did and just plug it on a regular ball tip. I bought a spark wire from Autozone and clipped it in half, and it fit on the Grubee/Bikeberrry CDI without any problem, and clips on the normal spark plug ball.
 
Last edited:
rohmell

rohmell

Active Member
Jun 2, 2010
1,531
6
38
New York
Mr. Ratchetbirds, thank you for your kind words.

But don't forget that you were extremely helpful by providing important and useful pictures of the insides of a Grubee Chiinese CDI, and I thank you very much for that.

We will not be simply copying the Chinese CDI, but instead redesigning it from the ground up. In fact, one of the engineers said that he doesn't want to see any schematics, "just show me the engine, and I will figure it out from there." (of course, I have the schematics on standby, if needed).

The plan is to have the following products, depending upon interest:
1) An assembled and tested CDI with internal coil
2) An assembled and tested CDI that uses an external coil. (Like the 'Roll Your Own CDI" thread)
2) A kit of all parts to build a CDI. (parts, PCB, enclosure, etc.

Everything will be open source, so to speak, all schematics and diagrams will be available, nothing potted, easy to see the parts and easy to repair in case of problems.
Using 'normal' off the shelf parts nothing weird and hard to get, except for the coil, which we might be winding our own, if we cannot find a suitable vendor of coils.
I don't know how long all this will take, we have just begun working on it.
 
rohmell

rohmell

Active Member
Jun 2, 2010
1,531
6
38
New York
Mr. Ratchetbirds, thank you for your kind words.

But don't forget that you were extremely helpful by providing important and useful pictures of the insides of a Grubee Chiinese CDI, and I thank you very much for that.

We will not be simply copying the Chinese CDI, but instead redesigning it from the ground up. In fact, one of the engineers said that he doesn't want to see any schematics, "just show me the engine, and I will figure it out from there." (of course, I have the schematics on standby, if needed).

The plan is to have the following products, depending upon interest:
1) An assembled and tested CDI with internal coil
2) An assembled and tested CDI that uses an external coil. (Like the 'Roll Your Own CDI" thread)
2) A kit of all parts to build a CDI. (parts, PCB, enclosure, etc.

Everything will be open source, so to speak, all schematics and diagrams will be available, nothing potted, easy to see the parts and easy to repair in case of problems.
Using 'normal' off the shelf parts nothing weird and hard to get, except for the coil, which we might be winding our own, if we cannot find a suitable vendor of coils.
I don't know how long all this will take, we have just begun working on it.
 
Ratchetbirds

Ratchetbirds

Member
Jun 12, 2011
125
1
16
Eastern Wash.
All very exciting and heady stuff goin on. Thank you for letting us know what is coming down the pike. Almost done with most of my upgrades, but still need to get back to my all-in-one unit to change the SCR and the resistors. I will post updated pics in the correct forum when I get done. Thank you for the kind words as well, I love doing teamwork projects.
 
fx-2

fx-2

New Member
Oct 7, 2011
125
13
0
Tucson Arizona
rohmell said:
Mr. Ratchetbirds, thank you for your kind words.

But don't forget that you were extremely helpful by providing important and useful pictures of the insides of a Grubee Chiinese CDI, and I thank you very much for that.

We will not be simply copying the Chinese CDI, but instead redesigning it from the ground up. In fact, one of the engineers said that he doesn't want to see any schematics, "just show me the engine, and I will figure it out from there." (of course, I have the schematics on standby, if needed).

The plan is to have the following products, depending upon interest:
1) An assembled and tested CDI with internal coil
2) An assembled and tested CDI that uses an external coil. (Like the 'Roll Your Own CDI" thread)
2) A kit of all parts to build a CDI. (parts, PCB, enclosure, etc.

Everything will be open source, so to speak, all schematics and diagrams will be available, nothing potted, easy to see the parts and easy to repair in case of problems.
Using 'normal' off the shelf parts nothing weird and hard to get, except for the coil, which we might be winding our own, if we cannot find a suitable vendor of coils.
I don't know how long all this will take, we have just begun working on it.
Click to expand...
Is there any progress on the Kits or complete CDI unit ? Have watched this thread an will build one once you have them ready . Thanks Dan
 
  • Like
Reactions: Twitchtopher
You must log in or register to reply here.
Top Bottom