electronic ignition... no spark

[HxPaul]

It could be that both LT coils might not be working on your stator plates.

[HxPaul]

EDIT.Have just watched your video and it seems that the LT coils are working.

[johnny650]

good idea i'll do that .
I'm hoping that I can use my vernier gauge to measure both the pickup height and the height of the centre of the magnet fingers off the mag housing baseplate which should give me an exact vertical alignment of the two.
Thats the theory anyway. Whether it is going to be possible is another matter lol

An external pickup is just making such sense right now. Trying to establish the correct proximity and alignment between the pickup and flywheel through a tiny slit in the flywheel is just madness . The only way I can see this working is to have an access slit above the pickup so that a feeler gauge can be used and some sort of adjustment facility to set the height of the pickup.

[johnny650]

EDIT.Have just watched your video and it seems that the LT coils are working.

yes they both seem to working fine . i have at least 55v AC from one of the LT coils which should be fine for charging the CDI capacitor.

I'm reasonably confident now that the issue has to be the pickups not pulsing the CDI due to misalignment .

What a nightmare ...does everyone have this problem when converting to electronic ignition I wonder.?

[johnny650]

What holty is referring to on the stators is the woodruff key slot should be in the position on the photo as a while back some came with the slot above the rivet and you could not set them up here is two good electronic flywheel on the left an li150 taper and the right a gp taper I've marked in white were the slot is if yours is above this say by 5/10mm then that could be your problem

Sent from my SM-A320FL using Tapatalk

I missed this post somehow ?

I did check the keyway position when i first got the flywheel because I read about the misaligned flywheels .
There is an image of my flywheel earlier in this thread which I believe has the correct keyway position yes !?

[johnny650]

Ah, OK. If you have a small red LED, connect this between the red and white on the CDI (anode to red). This will tell you that the pick up is sending a pulse.

this works brilliantly firedp thank you for the suggestion .
Your post actually coincided with a very old post I recently read of yours , on the LCGB forum where you suggested using Leds to test the Stator outputs.

It also works of course with the ignition low tension coil output (green wire) . Its handy to have Leds connected for an immediate visual confirmation whilst circuit testing instead of having to use a multimeter

Over the years I have often thought about constructing some sort of visual indicator for testing and monitoring the stator outputs for points and electronic stators and then Anthony brought out his excellent range of electronic ignition components with a CDI that incorporates Leds.

[johnny650]

OK a quick update.
I fitted the flywheel with some Engineers blue and the flywheel fits perfectly all round the crank spigot although the front edge of the fan sits proud of the mag housing rim 6mm

I put an LED across the stator LT coil wires (white and green at the CDI ) and spun the flywheel with my drill and the led flashed perfectly and the multimeter read 56v ACso the LT coil is definitely pulsing the CDI

I tried the same LED trick with the pickup (red wire to white wire) but no flashing light !....?

I measured everything from the mag housing base which the stator sits on and found the following
base to pickup top 42mm
base to centre of the pickup strips 34mm
base to centre of flywheel magnet fingers 34mm

So the pickup fingers are vertically centered exactly on the pickup strips yipee! so far so good.

i still haven't been able to measure the exact distance between the pickup strips and the magnet fingers but it looks very close to 0.5-0.7 mm no larger for sure so that looks ok too.

I guess the only possibility left now is a faulty pickup on both the stators ?! yet the pickups on both stators read 93 ohms (red wire to white wire) ?
I have a spare Vespa PX pickup which should be working. Until I can order a replacement pickup I might try and fix the vespa pickup externally on the flywheel with a small metal strip on the flywheel to trigger .

[firekdp]

Before you condemn the pick ups, try the LED across a 1.5v battery, some Led's require more voltage to light than others. If the battery can light it, then it should flash when connected across the pick up.
A better way to test the LT coil is do a similar test but with a neon lamp, the type fitted into electrical test screwdrivers.

[johnny650]

ok so are you saying that I put a 1.5v DC battery across an AC output from the pickup ? ie put both the battery and the LED in parallel across the wed wire and white wire from the pickup yes ?

[firekdp]

Also, a standard vespa pick up, will not work externally as it needs two magnets to produce the correct pulse.
The Chinese external pick ups work differently and are simply a magnet wrapped by a coil, so only need a ferrous metal, interacting with the field, to produce a pulse.