Making a CDI box mapper?

[pitobread]

I want to make this for a few reasons.  I was thinking of using an arduino to trigger the box and then map it out somehow... 

but I am not sure.  I would love to have it graphed out but that seems complex and i'm not a wizzard of programming.

Anyone ever seen anything like this in their travels?

[190mech]

Like this?
www.vespalabs.org/openvespa-com/programmable-ignition

[pitobread]

That seems to be a programmable ignition. I want something that gives me a curve of an existing cdi... I am probably going to go full analog and make a motor that runs a crank stub with a flywheel on it.

But it would be sweet if I could get it into the digital world.

[Lucass2T]

Try search through the RC radio control forums.
I myself once began on making my own programmable cdi ignition about 15yrs ago for as a school project.

www.rcuniverse.com/forum/engine-conversions-92/11636129-robs-gompys-old-tci-files-anyone-got-them.html

This guy Gompy (real name Rob) posten al lot of stuff and tutorials online about building your own programmable cdi ignition. Complete with parts lists, software and how to make your own circuit board (with UV light and acid).

[190mech]

I read a lot of gompys stuff a few years back,could never get a clear path to take as he always would be changing directions...
Here is another site that has some good info;
www.sportdevices.com/ignition/ignition.htm

[pitobread]

Yeah that test machine is more what im looking at... I need to make some sort of test bed to figure out the curves on some MVT CDI boxes so I can set them up properly

They won't even tell you what the base timing is so you can test and troubleshoot with a timing light....

[190mech]

My home made one is an old Mina case,a good size router,toothed belt,variac voltage controller,shaft is a lathe cut steel bar..
There is a short vid of it here;
49ccscoot.proboards.com/thread/18875/poor-mans-retarding-cdi-mod?page=1

[ThaiGyro]

The issues with two strokes and ignition timing are many. The CDI curves are quite luck of the draw", in some regards. High performance ones have the same issues.

One example: Many MX'ers not many years ago would play with swapping CDI's...a CR125 for a 250, say. Some times great results...other times poor or detonation.

On carbs, even one needle position (Leaner) can ruin an engine at high rpm's. You think, what? I have perfect main jet size, but your transition from the pilot performance to the main, with improper timing may have begun the damage.

I recall a Honda MT-125R that would blow by me in corners, but never get good enough top end. Hmmm. So many things it could be. Turned out to be a setup from a CR-125, different ignition timing, same everything else. It blew up quite often. Not enough retarding from 12,500 to 14,000 rpm. Those were total analog days. Easy...not really recordable.