PRD Fireball Shop Manual/Ignition Timing


Ignition timing is adjustable on both Oppama ignitions, and Easy Start Ignition systems (released January 2012 in USA).

The basic procedure will require measuring a displacement distance of piston travel before Top Dead Center, setting the piston at that distance, and then adjusting the ignition coil to be triggered at that point.

There are two ignition systems that have been used on the PRD Fireball in the US, and the steps to update them are different.

Pre-2012 (Oppama)Edit

2012 to Present (Easy Start Ignition)Edit

See RLV's Easy Start Ignition Adjustment for the procedure to set your timing for an Easy Start Ignition.

The procedure below reflects the same basic steps as officially recommended by RLV.

What You'll NeedEdit


  1. Wrench to remove spark plug.
  2. Caliper.
  3. Allen head wrenches.


  1. Remove the sparkplug.
  2. Rotate the crankshaft such that the piston is approaching Top Dead Center (TDC), but not quite there yet.
  3. Insert the depth gauge of the caliper into the cylinder through the spark plug hole, bringing the gauge to the tip of the piston crown.
  4. Hold the caliper normal to the head, and keep it centered.
  5. Rotate the piston up to TDC and past.
  6. Carefully zero the caliper by pressing the zero button.
  7. Add 0.200" to the caliper reading - this should make the depth gauge longer.
  8. Rotate the engine to roughly Bottom Dead Center (BDC).
  9. Insert the depth gauge of the caliper into the cylinder, again, holding it normal and as centered as possible.
  10. Raise the piston toward TDC until it touches the caliper - ensure you raise it in the correct direction for the engine's normal operational direction.
  11. With the engine in this position, adjust the ignition sensor such that the "button" is within the hollowed out region of the ignition timing wheel. The "button" should be tangentially coincident, albeit on non-intersecting planes, to the upper edge of the timing wheel.
  12. Hand tighten your ignition timing plate's Allen bolts.
  13. Repeat the process to ensure the location of 0.200" is correct.
  14. Torque the Allen bolts.
  15. Reassemble.