no spark help something smiple stupid

I'd start by removing the magneto cover. If that rain got in there it could certainly kill the spark.

Ok, if u look at the stator coil inside the magneto housing it should have
(1) a blue wire exiting the winding at the top.
(2) a white wire exiting the winding at the bottom.
Both of these should exit the magneto housing along with a black wire. The black wire should be attached inside the magneto housing to the stator coil laminates with an eye connector to one of the 4 mounting bolts that attach the stator coil to the motor. U need a good connection here.
Also, look at the laminate corner just above the coil winding. The inner end of the winding is soldered to the laminate core here & also needs a good connection.
If ur not using the white wire to run a small light or charge a battery via a rectifier, insulate the free end with heatshrink (or snip it off at the coil, but leave the solder tab intact). Check that all these are good & get back to us. Cheers

there are newer coils that have no white wire, there are older coils that have a brown wire - find a wire that measures 320-360ohms to ground & use it for the power to the CDI blue wire

Thanks for that regarding the older/newer stator coils Crassius. If he has a newer (no white wire) type it'll be easy, there will only be 1 insulated wire exiting the coil & as Crassius noted it should read somewhere in the viscinity of 390 ohms. A variation either way is normal. If it has a white wire it'll read only a few ohms, almost a dead short. The laminate core must also make a good connection to ur motor so if it got moisture in there check for high resistance between the laminate & motor.
I think everyone into these motorized bicycles should have a small, inexpensive multimeter for troubleshooting things like this. If ur not familiar with the use of these there are small publications like "1001 uses for multimeter's" that will give u the lowdown. I imagine there are plenty of online guides to the use of these as well. Cheers