electronic ignition... no spark

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johnny650
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Thu Dec 06, 2018 10:16 pm

made a video of my testing the new K2 pickup today and still no sign of a spark.
I cannot believe a few simple components have me beat .
[youtube]https://youtu.be/W9I4gD9Uc-Q[/youtube]
https://youtu.be/W9I4gD9Uc-Q

mick1
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Thu Dec 06, 2018 11:13 pm

I couldn't see a spark on my engine as well. Moved it into the garage, switched of lights, closed doors, pitch black.......no spark.

Put same spark plug in engine and engine fired up first time !! took spark plug out.....still no spark, put plug back in and engine fired up again !!

I came to the conclusion that "seeing" a spark didn't necessarily mean there wasn't one. I then fitted one of the flashing suppressor caps and could see it working fine.

Do you have the confidence to put your finger in the suppressor cap and kick it over :mrgreen:

It certainly proves if there's power there or not.

johnny650
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Fri Dec 07, 2018 12:19 am

mick1 wrote:
Thu Dec 06, 2018 11:13 pm
I couldn't see a spark on my engine as well. Moved it into the garage, switched of lights, closed doors, pitch black.......no spark.

Put same spark plug in engine and engine fired up first time !! took spark plug out.....still no spark, put plug back in and engine fired up again !!

I came to the conclusion that "seeing" a spark didn't necessarily mean there wasn't one. I then fitted one of the flashing suppressor caps and could see it working fine.

Do you have the confidence to put your finger in the suppressor cap and kick it over :mrgreen:

It certainly proves if there's power there or not.

ha ha no I am not going to stick my finger on the end thanks Mick .. :D I've had a fair few shocks and don't want another lol.
You have made a good point though . Now I have the carb issue sorted out I'll see if it will fire up tomorrow.

mick1
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Fri Dec 07, 2018 8:18 am

Pity......i was looking forward to the video that confirmed there was power :lol:

johnny650
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Fri Dec 07, 2018 10:22 am

yeah me to Mick :lol: I think I'm missing a flux capacitor :D

I read online last night that some flywheels have positive /negative pickup triggers and some have negative /positive depending on where the magnets are positioned.

I'm beginning to wonder if I have a reverse polarity flywheel thatisn't compatible with my CDI :?

I am certain that it is a AF Rayspeed flywheel but they may have them made to suit their own stator , pickup and CDI.

The only way I can be sure of the pickup output is to use an oscilloscope..... Apparently I should see both a negative and a positive output as the pickup passes the trigger fingers if the pickup is properly aligned and working.

I have one of those cheapo Chinese manufactured oscilloscope kits I bought a while back I might try and get it set up and working . It would make testing a whole lot easier .

I cannot believe that there isn't someone on this forum reading this thread that hasn't got the experience and knowledge to know how to sort this sort of problem ...god knows the net is full of Lambretta ignition problems. :roll:

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HxPaul
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Fri Dec 07, 2018 4:39 pm

There's a bit in here about AF flywheels
https://www.facebook.com/groups/1655094 ... SEARCH_BOX

firekdp
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Fri Dec 07, 2018 7:23 pm

johnny650 wrote:
Fri Dec 07, 2018 10:22 am
I read online last night that some flywheels have positive /negative pickup triggers and some have negative /positive depending on where the magnets are positioned.
Where did you read that, as I've never heard that before??
I believe there are problems with alignment/ misfiring on the AF lightweight ones, but yours like a standard lightened Indian one.

Using the LED to test the LT feed coil is a waste of time, as even a faulty coil could put out enough to light it. As said earlier, a neon lamp is better for this as it it needs a greater voltage to light. However your voltage checks seem to prove this ok.

The voltage readings of the pick up are also not going to tell you a lot either. The positive pulse, that occurs when both magnetic fingers are over the pick up, is of a very small duration so hardly detectable on a volt meter amongst the AC waveform produced by the other magnets. Your reading is about right for the average voltage of that waveform. If you have a oscilloscope then that is the best way to have a look and see what is going on.

Looking at where you are earthing the CDI and plug, have you removed the paint from these areas to ensure good contact?

johnny650
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Fri Dec 07, 2018 8:41 pm

HxPaul wrote:
Fri Dec 07, 2018 4:39 pm
There's a bit in here about AF flywheels
https://www.facebook.com/groups/1655094 ... SEARCH_BOX
cheers Paul good link I'll join the group . ;)

johnny650
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Fri Dec 07, 2018 8:55 pm

firekdp wrote:
Fri Dec 07, 2018 7:23 pm
johnny650 wrote:
Fri Dec 07, 2018 10:22 am
I read online last night that some flywheels have positive /negative pickup triggers and some have negative /positive depending on where the magnets are positioned.
Where did you read that, as I've never heard that before??
I believe there are problems with alignment/ misfiring on the AF lightweight ones, but yours like a standard lightened Indian one.

typical !....I've had the link cluttering up my tabbed browser all week and close it seconds before reading your post . If I find the reference I'll post it.

I did find this similar post by Fast n furious on LCGB (scroll down to last post ) I have a feeling it was originally one of Captain Pugwash's posts where I read it
http://www.ilambretta.co.uk/forum/viewt ... est#p96325

yes earthing is fine checked and double checked but I have some great news .

I have a spark a nice big fat strong healthy spark. The scoot fired up and ran in the shed this afternoon and revved like a racer ....fantastic the first time it has run properly all summer .It needs jetting and timing strobed
I'll make a seperate thread about how I solved it and include all the tests and checks I have done and all the infomation and help I have got from you guys .

Thank you one and all :D

johnny650
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Sat Dec 08, 2018 2:22 am

I'm sure that anyone following this saga will be pleased (or maybe relieved ?) :lol: to hear that tonight I got my scoot running after probably 6 months of problems with drive side oil seal leaks, cylinder leaks , carburetor issues and constant no spark problems.

Thank you all who offered help and advice it was very much appreciated

After months of problems I ditched my 6v points ignition and upgraded to a 12v AC Electronic ignition system. then I faced weeks of no spark problems but today I finally solved the no spark issue. It was simply that the pickup needed to be 1.5 thou closer to the trigger magnets on the flywheel.

Who would have thought that 1.5 thou would make the difference between no spark and perfect spark ! :shock:

All I did was to remove the trigger magnets from the flywheel and shim behind them with some thin pieces of business card approx 3 thou thick. once crushed under the magnets the actual shim would probably have been 1.5 thou
[youtube]https://youtu.be/CyW_E38TeV0[/youtube]
https://youtu.be/CyW_E38TeV0

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