Re: Please Help!!! Ive replaced the entire electrical system and it still wont start!
The fact you replaced the magneto is suspect in itself, the electrical system ground is supplied to the engine body by the tab at the top of mag being soldered to the engine body. If the common ground for the system can't reach the head for the plug ground you will never get a spark. Just Ohm check the tab right out of the mag to the threaded part for the plug, it should read a dead shot (0 ohms).
The magneto coil should have about 350 ohm across the black and blue wires.
There's no way to check the CDI box except substitution.
That is not entirely accurate...
With a good Ohm meter you can check a portion of the CDI circuit like this.
Set you meter in a range to measure ~1K, like 2K or 10K.
Disconnect the CDI from the bike.
Put + (red) probe to the Black (ground) CDI wire.
Put the - (black) probe to the inner part of the plug cap that snaps on the top of the plug.
Around 692 ohms give or take a dozen ohms or so confirms the CDI circuitry does in fact function from ground to hot plug tip.
If you are unsure how an ohm meter works, when you touch the probes together it should read 0 ohms (adjust meter as needed), and a dead short.
Pegged at infinite ohms regardless of scale is an open.