1. First make sure you have resistor type plugs.
2. Check Ground Continuity. From inside the spark plug cap to the engine, readings should be 6-7K ohms. If this checks good, go to step 3.
.....a. If one or two are out of range, remove the plug cap and check the resistance between the wire and engine ground. The reading should be between 1200-1600 ohms without the caps.
3. Open the electrical box and check for correct conections between the stator, CDI, coils and the board. Check for pinched wires, corroded connections or water in the electrical box.
Spend the extra moment to check the back side of the board for rust.
.....a. Make sure the yellow stator wire is connected to the "YELLOW" on the terminal board and not the yellow/purple MFD jumper.
.....b. Make sure the is no continuity between the black/yellow and black on the terminal board (with the tether installed).
.....c. Make sure the red/purple wire at the CDI has 12 volts.
.....d. While cranking make sure the brown wire to the CDI has 5-9 volts.
.....e. Check stator resistance. Black meter wire to the black wire from the stator and the red wire goes to;
engine stud: 0-1 ohm.
Purple Wire: 1200 ohms
Gray Wire: 88 ohms
Brown, red, green, blue red/purple: open reading
Then red/purple to yellow .75 ohms.
.....f. Disconnect coil wires and check the resistance from the primary side. Black/White to:
Yellow/Brown: .35 ohms (mag)
Black/Blue: .35 ohms (center)
Black/Green: .35 ohms (PTO)
Secondary Side to:
1200-1600 ohms without plug cap
6000-7000 ohms with plug cap.
4. Check trigger points as outlined in tech section.

If you have a mis-fire or early RPM drop out that makes no sense, test the LR54 (voltage regulator).
With the engine idling, check the voltage at the gray wire, it should be above 3 volts with less than 1/4 tank of fuel.
Pink wire should be below 3 volts
Tam wires should be above 5 volts.
IF these readings are incorrect replace the unit.
If the battery is low so cranking RPM's are down, the engine may have spark with plugs removed BUT have no spark or a weak spark under compression.
Make SURE the battery is fully charged!!!