scooter spark questions

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scooter spark questions

Post by chazdo2 »

I am trying to understand exactly how the spark is produced. Reason being Im having trouble with my Malaguti Yesterdays spark. On almost everything I have ever worked on the flywheel spins at a certain point the magnet passes the pickup then makes and breaks the coil to produce the spark. The flywheel on the scooter is all magnetic I cant find the small magnet and I think the entire flywheel is magnetic because my tools stick to it everywhere on it. Can somebody explain to me exactly how the spark is produced? The cdi/coil unit has to get a signal exactly when to spark I need to know what does it. Any help much appreciated!!!!!!
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Re: scooter spark questions

Post by motormike »

I looked at a Malaguti Yeasterday stator and clearly it is performing the job you describe, signaling the coil to make fire.
Not sure how that flywheel is constructed, but I guess it has some hidden element to generate the signal.
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Re: scooter spark questions

Post by pitobread »

Short answer, if you don't see a pickup and a raised boss like a reluctor ring, it uses the swapping of the north and south poles of the magnet. To a piece of steel it will just seem magnetic all over but if you got a pole checker(used for winding motors) or another magnet you would see the poles as attraction and repelling of the same pole. N-S-N-S etc. So the AC voltage goes high, then goes low and the field collapses creating spark.

Its the old as dirt way of making spark, like every briggs and stratton, chainsaws all used to use this principle.
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