I am having the same problem went thru and bought a magneto cdi and plugs still the same will not spark unless i hold the plug it it cause i have the cdi mounted on the frame where it is painted or what this is my daily driver to work so got to get it figured out plz helppp
The CDI is normally in a plastic casing, the painted frame will not affect the CDI in any way or form.
Sparks if you hold it? Well if you're doing that right then it's sparking inside the motor as well. Now that leaves you with not enough fuel/air, a weak magneto that will only make the plug spark outside the motor, or a faulty plug, but since you ran through getting new ones perhaps it's something you haven't thought of or maybe don't know about. Magnet on correctly on the crank? If it's installed upside down you'll still get a spark but it won't happen at the right time and you'll never get the bike running. Take the plug out and engage the clutch with the wheel and turn it till you can clearly see through the spark plug hole that the piston is in the highest position possible. This is normally called top dead centre.
With the piston at top dead center (tdc) look at the magneto magnet under the mag cover. There's a slot for the key to keep the magnet in place, and the magnet is held down by a nut. You'll need to take the nut off to see the slot or judge it by the position of the magnet itself. The slot would be at "1 o'clock" on the magnet as it were being installed but the angle of the magnet would be a dead giveaway. Look at this pic. Just remember the piston needs to be at its highest point to make an accurate judgment. You can feel the highest point as well by holding a pen against the piston through the plug hole and feel for when the piston is at the very highest point. Look at pictures, first one is how the magnet is aligned when correctly installed in the motor with the piston TDC (sourced from Fabian)
This next image is how the magnet will look if installed backwards, even with the nut on the magnet you'll be able to tell its wrong simply by the tilted angle, normally the magnet should be basically horizontal
Even if this isn't your problem you'll have an idea of what to do in the future should you ever tear a motor down. Please keep up updated.
