Setting the timing sensor

Setting the timing sensor

Watch the walkthrough

Watch on YouTube ↗ · JETSURF tuning. Timestamps in the steps below follow the video's on-screen counter (0:00–3:14).

The timing sensor sets the engine's ignition advance. This is a measure-and-adjust job — you find the magnet's zero point, rotate slowly to top dead center, read the advance value, and nudge the sensor until it lands in range. You need a way to read the advance value off the board.

Tools & supplies

• Medium-strength (blue) Loctite
• Bright light source (to spot the magnet ignition point)
• Diagnostic tool / reader for the ignition advance value
• The timing carrier / rotation tool

Fit the sensor

1. 0:00 — Secure the sensor bolts with medium-strength Loctite.
2. 0:19 — Set the timing sensor roughly in the center of its adjustment range.
3. 0:39 — Connect the wiring to both the sensor and the ECU.

Find the ignition point

4. 1:02 — Using a light source, locate the magnet ignition point.
5. 2:01 — If you rotate past the magnet position, start the rotation over from the beginning.
6. 2:22 — With the exact 0.00 position on the magnet identified, slowly rotate the carrier toward top dead center (TDC).
7. 2:30 — Move very slowly so you can read the exact value at which the reading stops.

Read & adjust the advance

8. 2:38 — Read the ignition advance value. (In the video's example it measured 0.107.)
9. 2:45 — Check it against spec: acceptable range 0.080–0.160, optimal 0.120.
10. 3:03 — Adjust by moving the timing sensor: right decreases the value, left increases it.
11. 3:14 — Move the sensor gradually and re-measure until you reach the target advance, then lock it down.