new high RPM Jaguar CDI

[Deleted member 12676]

Timing factors

useful info from http://www.msdpowersports.com/FAQ/

Timing factors

factors requiring more ignition advance:
low cylinder pressure, low spark energy, high fuel octane, rich fuel mixture, cold ambient temperature, low combustion turbulence (no squish band), light engine load

factors requiring more ignition retard:
high cylinder pressure, high spark energy, low fuel octane, lean fuel mixture, hot ambient temperature, high combustion turbulence, heavy engine load (heavy rider or going uphill)

 

[Deleted member 12676]

new Jaguar CDI video

After buying three different timing lights and they all being only for four strokes or not working at all (revenge of the orientals) I finally made my own LED timing light. I successfully used it to make this video showing the changes in ignition timing with changes in RPM. It is of the regular Jaguar without the lessened ignition retard at high RPM. Next I will make that and record the timings and make resultant graphs.
http://youtu.be/aTCKmnqaF6g

 

[Fabian]

Great video.

Can you make a video of the OEM CDI ignition timing and place it on the graph for comparison with the other Jaguar CDI graphs showing various jumper settings, as well as making a graph of the new Lightning CDI.

 

[Deleted member 12676]

Jaguar CDI timing curve graph

Here is the graphed timing curve of the CDI in the video:

 

[Fabian]

So that particular graph is of the Jaguar CDI with jumpers attached to the "A" Jumper pins and the "B" Jumper pins?

 

[Deleted member 12676]

I cant answer with absolute certainty because of minor design changes that have happened during its evolution.
The details of values hold no importance at all when compared to the results.
The graphs just give people an idea of what is happening technically. The only thing that really matters is what settings give you the best results.
There are so many variables that it is hard to predict what is the best setting for any engine.
16 ohms is what is usually the best input resistance, and 4.9uf is around the most commonly used value of timing capacitance.

 

[Fabian]

A prolix reply Jaguar.
Can you just tell me what the jumper settings were on that CDI you tested?

 

[Deleted member 12676]

This is my latest version that replaced the jumpers with on-board micro switches and the capacitors are of slightly different value.

 

[Fabian]

Ahh, that explains things. Can you post a photo of the circuit board and micro switches. I am particularly keen to see how the micro switches are laid out on the board and their ease of access.to adjust the settings.

 

[Deleted member 12676]

You can find that on my pages for JNMotors: http://www.dragonfly75.com/motorbike/JNM/CDI.htm