H1D/H2 CDI Ignition
Use the diagram below for reference:
No Spark on any Cylinder
- Make sure kill switch is in "Run" position (if present).
- Make sure the four ground wires of the CDI units have good
connections to the mounting plate.
- Make sure the CDI monting plate has a good connection to frame
ground with a ground wire from it to a grounding bolt.
- Measure the Low Speed coil resistance between Green & White wires
from stator (3 pin connector). It should measure approximately 200 ohms
and no less than 180 ohms.
Intermittent or Missing Spark on one or
- Install new sparkplugs... properly gapped.
- Insure that ignition coil mounts have a clean ground to frame.
- Insure that motor has a solid frame ground. Engine case to battery
should measure 0 ohms.
- Check to see if plug wires are arcing to frame or engine. (A
darkened room works best.)
- Measure pickup coil resistance on all pickups... single White wires
to ground should each be approximately 200 ohms and no less than 160
- Measure primary resistance of each ignition coil. It should measure
approximately 0.8 ohms from the red wire to gnd. Touch the meter leads
together and read that resistance. Then subtract that from the measured
coil primary resistance to get actual resistance.
- Measure secondary resistance of ignition coils. It should measure
approximately 4.5K (4,500) ohms from sparkplug cap to gnd.
Testing CDI Boxes
- Individual ignition units can be swapped between cylinders by
swapping both the Red & White leads from one box to another to determine
if a dead cylinder can be revived with a different ignition unit.
Testing the rectifier unit with an
- Testing is with analog meter with meter set at Rx1K and meter
zeroed when leads are touched together. All CDI leads must be
1. Meter - connected to CDI Black/White
Meter + connected to: Grn = 3.9
Blu = 3.9
Wht = 12
Lt Grn (all) = infinity
2. Meter + connected to CDI Black/White
Meter - connected to: Grn = infinity
Blu = infinity
Wht = some high value
Lt Grn (all) = 3.9
Any reading substantially different than shown above indicates a
Testing the rectifier unit with a digital meter that has a
diode test function
1. Meter - connected to CDI rectifier unit
Meter + connected to: Grn = approx. 0.6v
Blu = approx. 0.6v
Wht = approx. 1.2v
Lt Grn (all) = no
2. Meter + connected to CDI rectifier unit
Meter - connected to: Grn = no reating
Blu = no reading
Wht = no reading
Lt Grn (all) = approx. 0.6v
Testing the rectifier unit with a battery and test light
1. Connect battery - to CDI rectifier unit
Black/White, and battery + to one wire of test lamp
other wire of lamp connected to: Grn = lit
Blu = lit
Wht = lit
Lt Grn (all) =
2. Connect battery + to CDI rectifier unit
Black/White and battery - to one wire of test lamp
Other wire of lamp connected to: Grn = not lit
Blu = not lit
Wht = not
Lt Grn (all)
Alternative CDI Test
An alternative CDI test is offered
- A defective regulator/rectifier (open) can cause misfire/rev limiting.
- A defective hi spd coil can cause rev limiting at approx 4000 rpm.
- Inadvertently swapped coil/pickup wires between cylinders can cause
difficulty starting and/or misfiring.