I wasn't aware of any motorcycles that were using a multi strike style or multi fire ignition system up till now. It is a single 4 stroke motocross 450cc. Even more interesting that it is a CDI system. It appears to operate up till 4,500 rpm and then return back to a convectional single fire. Obviously being used to help with low speed running as it appears to extend the spark duration aprox 40%.

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James H wrote on May 6^th, 2017 at 7:35am:

it appears to extend the spark duration aprox 40%.

I dont know anything about CDi ignition so cant comment, but you have proved the longer spark time due to that extra pulse.
Great find James 8-)

James, this is very, and I mean very interesting.  I missed the double strike completely until zoomed in.

This whole thing would, or should be posted somewhere in the bigger forum. I marked a JPEG showing where 1 MS is, yours is about 1/10 of that for a fire time.  Normally in a gas engine  anything less than 1 MS is broaching on the edge of a missfire due to lack of fuel, plasma from flame or mechanical issues.

This event seems to happen in 1/10 of a normal fire time. I have no idea if there is a setting issue on the screen I have missed or what the deal is here?, maybe Mick could comment.

Mick, James could explain better but most bikes run CDI ( capacative discharge ignition) always IMO I thought it nothing more than as stated supplemented with a capacitor to upscale the event, could be wrong, maybe James could chime in.

James, interesting thing with the scope is you will pick up things the others in the industry have no clue, also will over time give you a good thought process for reparing said units, meaning you now know what a good one looked like.

Good for you

StitchB   AKA Larry

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James, interesting to note and I tried to find the file for it, but seems I have lost it.

On my 03 KLR, the alt sends up an AC signal to the CDI and coil, it is never turned into DC which is normal in most casses.

Also interesting is the voltage on the said AC is about 120, about what you would find in a house socket.  Also dully noted is the coil is physically about the size of a roll of nickels, IMO simply the input is 12 times greater than 12 volts so volts times amps equals watts, hence you would not need nearly the windings in the coil to make it happen.

The other interesting thing as in the picture the signatures being AC move up and down like one would think and not from a 0 point then up 12 volts but in a classic sine wave, and also the fire time on the spark plug also looks like a screw or sine wave moving up and down rather than a voltage KV spike then dying out over time.

I found the power to the coil by accident using my DVOM. Thought I had it on wrong setting when in fact it was actually making AC, not DC and @ 120, will see if I can find the file, or capture another one.

Larry

StitchB wrote on May 9^th, 2017 at 4:25am:

This event seems to happen in 1/10 of a normal fire time. I have no idea if there is a setting issue on the screen I have missed or what the deal is here?, maybe Mick could comment.

Good morning Larry

I took the firing time as being normal for this ignition system when measured at lower RPM because of the energy produced by the coil, so as to keep that fuel burning to completion.

Id like to see more examples. 8-)

James H, can you connect an adjustable spark tester to one of the plug wires? See if the coil can fire an ST125 and scope the coil primary and secondary please.

Ray

rayray wrote on May 9^th, 2017 at 7:42am:

James H, can you connect an adjustable spark tester to one of the plug wires?

Ray it only has ONE! [smiley=chopper.gif]

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I guess one coil-on-plug extension lead from the coil to the adjustable spark tester would work?

Ray

Mick wrote on May 9^th, 2017 at 5:19am:

StitchB wrote on May 9th, 2017 at 4:25am: This event seems to happen in 1/10 of a normal fire time. I have no idea if there is a setting issue on the screen I have missed or what the deal is here?, maybe Mick could comment. Good morning Larry I took the firing time as being normal for this ignition system when measured at lower RPM because of the energy produced by the coil, so as to keep that fuel burning to completion. Id like to see more examples. 8-)

Mick, I'm with you as have 2 bikes with them but never had problems or the occasion to actually look. As you stated sure could be just how it is............which is what I suspect.

As we say on the forum, what does a good one look like, I guess we will find out?

Larry