CDI READING,MAP PLOTTING AND PROGRAMMING

[Dave G]

I put this info together a while back and thought it's about time I shared it!. Here's a few taster pics first to give you an insight.

[imghttps://themotorbikeforum.co.uk/uploads/monthly_2025_12/20250602_154032.jpg.259b0288920ebf11fcd6f1871402adbf.jpg][/img]



Here's the PDF I put together. Any questions?

https://themotorbikeforum.co.uk/applica ... 91af4fb4e6

[Yorick]

Any clues?

[Dave G]

About what?

[Yorick]

About what?

I have absolutely no idea of what any of it is about.

[Dave G]

About what?

I have absolutely no idea of what any of it is about.

I got rid my ECU and replaced it with a CDI unit when I did a carburettor conversion. I initially used a standard off the shelf CDI unit designed for use with NC450 sohc engine. When I upgraded to the NC450S dohc engine I wasn't sure whether the CDI would or wouldn't be compatable so I decided to go for a programmable CDI to allow me to experiment. The pdf that I attached to the first post explains how I did this. Any questions!, please ask.

[Yorick]

About what?

I have absolutely no idea of what any of it is about.

I got rid my ECU and replaced it with a CDI unit when I did a carburettor conversion. I initially used a standard off the shelf CDI unit designed for use with NC450 sohc engine. When I upgraded to the NC450S dohc engine I wasn't sure whether the CDI would or wouldn't be compatable so I decided to go for a programmable CDI to allow me to experiment. The pdf that I attached to the first post explains how I did this. Any questions!, please ask.

That was complete Chinese to me. I'll leave you to it.

[Dave G]

Maybe this isn't the right place for this kind of stuff!

[Yorick]

Maybe this isn't the right place for this kind of stuff!

I've been riding and fettling bikes 50 years and never come across this before.

[Count Steer]

Maybe this isn't the right place for this kind of stuff!

I'm sure there'll be some interest, it's just a bit of a quiet time as people finish digesting their sprouts and stiffen the sinews ready for NYE.

[Dave G]

Maybe this isn't the right place for this kind of stuff!

I'm sure there'll be some interest, it's just a bit of a quiet time as people finish digesting their sprouts and stiffen the sinews ready for NYE.

If there's anybody out there wanting to replace there CDI with a programable variety so that they can play around with the ignition timing but revert back to standard ignition if things don't work out! then this PDF might be a good bedtime read.

[mangocrazy]

I'd have been interested to read the PDF, but when I clicked on the link I got this message:

This attachment is not available. It may have been removed or the person who shared it may not have permission to share it to this location.

[Dave G]

Anybody else struggling to download PDF. Maybe it's me doing something wrong. I tried it as an attachment first but it wouldn't allow me to do so!

[Dave G]

Am I allowed to attach PDF's to a post?. Some forum's seem to allow it!

[Dave G]

Lets see if this works!

[KungFooBob]

Hi Dave!

The NC450 sohc, is that the Zongshen engine that's very similar to the old Honda RFVC lump?

What was the driver for replacing the EFI throttle body with a carb?

Have you considered points over CDI (thats a joke btw)?

[Dave G]

Hi Dave!

The NC450 sohc, is that the Zongshen engine that's very similar to the old Honda RFVC lump?

What was the driver for replacing the EFI throttle body with a carb?

Have you considered points over CDI (thats a joke btw)?

I'm using the NC450s engine now which is basically the same as the NC450 but DOHC. I think the NC450 is an early Honda CRF450 copy. The story behind the conversion is here.

https://www.motoblog.it/post/fantic-cab ... ve-gillery

[KungFooBob]

Oh, I remember who you are now!

Instead of a carb, did you consider a custom EFI setup, like a megasquirt?

[Dave G]

Oh, I remember who you are now!

Instead of a carb, did you consider a custom EFI setup, like a megasquirt?

I developed a system to modify the fuel injector times, but still had reliability issues with ECU so decided to get rid of ECU and all associated sensors and replace with CDI and carb. This bike review talks about it.

https://www.bikebound.com/2025/09/13/dohc-caballero/

[crust]

Which CDI did you use? Was it from these people?

https://www.ignitech.cz/en/

[Dave G]

Which CDI did you use? Was it from these people?

https://www.ignitech.cz/en/

Yes, it's this one.
https://www.ignitech.cz/en/vyrobky/dccdip/dccdip.htm