Electrical Troubleshooting for Parsun Carbureted Outboards
This guide and all component values below apply only to carburetor models in these engine families: F2.6, F4/F5, F5A/F6A, F8/F9.8, F9.9/F15, F20/F25 and F20A.
F20A EFI, F30/F40 and F50/F60 are outside this guide's scope. Use their separate alarm-indicator guides:
- F20A EFI alarm indicators and buzzer guide.
- F30/F40 and F50/F60 EFI alarm indicators and buzzer guide.
An engine that will not crank needs different checks from one that cranks but will not start. Identify the symptom before replacing a coil, starter or rectifier.
Check the full model designation and the part number fitted to your engine. Match the wiring and test procedure to your engine's manual; similar horsepower does not establish compatibility.
Start With the Symptom
| Symptom | Check first |
|---|---|
| Electric starter does not turn the engine | Shift control in neutral, battery condition, battery terminals, main cable connections and the specified fuse. Do not bypass the neutral-start protection or bridge starter terminals. |
| Engine turns over but will not start | Stop-switch lanyard correctly fitted, ignition switched on where applicable, fresh fuel, fuel supply and spark-plug condition. A starting problem does not by itself prove an electrical fault. |
| Battery loses charge | Battery condition and connections, electrical loads and the charging-system checks for the equipment fitted to your engine. A failed battery or poor connection can resemble a charging fault. |
With the engine stopped, look for loose plug caps, damaged insulation, corroded connectors and disconnected earth wires. Replace a blown fuse only with the specified rating. If it blows again, find the fault before fitting another fuse.
For fuel and cooling checks, see Troubleshooting common Parsun outboard issues.
Safety Before Electrical Checks
- Secure the outboard to the boat or a suitable stand and put the gear control in neutral.
- Stop the engine, switch off the ignition, remove the key where fitted and remove the stop-switch lanyard before disconnecting components.
- If a battery is fitted, disconnect the negative cable first, then the positive cable before working on wiring. Reconnect positive first and negative last, with the ignition off.
- Work in a ventilated area away from smoking, flames and sparks. Do not perform a spark test if fuel is leaking or fuel vapour is present. Repair the leak and ventilate the area first.
- Keep hands, clothing, tools and test leads away from the flywheel, starter and propeller. Wear eye protection.
Resistance checks below are performed with the engine stopped and the component isolated. Spark and charging tests require a different setup because the engine must turn or run. Prepare those tests completely before restoring power or enabling the ignition.
Using a Multimeter for Resistance Checks
- Disconnect the component from the rest of the circuit as described in its service manual. Switching off the ignition alone does not isolate parallel electrical paths.
- Set the meter to resistance (Ω). Never use this setting on an energised circuit or while cranking the engine.
- Check the resistance of the meter leads by touching the probes together. Use the meter's zero function, or account for lead resistance, particularly for windings below 2 Ω.
- Measure between the specified wires or terminals, with clean contacts and the component at 20 °C for the reference table below.
- Check whether the measurement includes the spark-plug cap. A resistor cap adds resistance; a winding measured with its cap fitted cannot be compared directly with a cap-removed specification.
A reading within the specified range does not prove that a component works under load or when hot. If a reading is outside the range, first recheck the part number, test points, connections, temperature and meter accuracy before deciding to replace it.
Electrical Component Resistance (at 20 °C)
The resistance values below are supplied by Parsun for the carburetor models listed above, measured at 20 °C. kΩ means thousands of ohms.
Use the service manual to identify test connections and whether to include the spark-plug cap. Match the specification to the part number fitted to your engine before assessing the reading.
| Model | Part number | Component | Test points / resistance |
|---|---|---|---|
| F2.6 | F2.6-04000600 | Ignition coil assembly | High-voltage winding: 6.9 kΩ ±10% |
| F4/F5 | F4-04000038 | Ignition winding assembly | Low-voltage winding: 1.5 Ω ±10% High-voltage winding: 6.5 kΩ ±10% |
| F5A/F6A | F6-04000400 | Ignition coil assembly | White / Black: 424 Ω ±10% High-voltage winding: 2.87 kΩ ±10% |
| F8/F9.8 | F8-05000200 | Pulser coil | 207 Ω ±20% |
| F8-05000300 | Magneto coil | 320 Ω ±10% | |
| F8-05000500 | Ignition coil assembly | Low-voltage winding: 0.3 Ω ±10% High-voltage winding: 12.2 kΩ ±10% | |
| F9.9/F15 | F15-11030000W | Electromagnetic solenoid | 4.2 Ω ±10% |
| F15-07000600 | Ignition coil assembly | Low-voltage winding: 0.2 Ω ±10% High-voltage winding: 11.8 kΩ ±10% | |
| F15-07000200 | Pulser coil | 207 Ω ±20% | |
| F15-07000300 | Magneto coil | 350 Ω ±10% | |
| F15-07000400 | Charge coil A & B assembly | 0.4 Ω ±10% | |
| F20/F25 | F25-05120000 | Ignition coil assembly | Low-voltage winding: 0.3 Ω ±10% High-voltage winding: 12.3 kΩ ±10% |
| F25-05140000 | Stator assembly | Brown / Blue: 716 Ω ±10% Yellow&Green: 7.7 Ω ±10% Yellow&Yellow: 1 Ω ±10% | |
| F25-05110000 | Pulser coil | 330 Ω ±10% | |
| F20A | F20-05000200 | Magneto coil assembly | Black & Red / Green & Red: 25.5–34.5 Ω Blue / Blue: 0.77 Ω ±1.2 Ω Green / Green: 0.3 Ω ±0.5 Ω |
| F20-05000100 | Pulser coil | 152–228 Ω | |
| F20-05000400 | Ignition coil assembly | Spark-plug cap: 3.75–6.25 kΩ High-voltage winding: 9.5 kΩ ±10% |
For rectifier DC output values, see Charging and rectifier checks.
Starting Switch F15-13000200W
Disconnect the switch from the wiring and test it without power. “X” indicates continuity between the listed wires; “—” means no connection is indicated for that switch position.
| Wire pair | STOP | RUNNING | START | PUSH |
|---|---|---|---|---|
| Red / Brown | — | — | X | — |
| Red / Yellow | — | X | X | — |
| Black / White | X | — | — | — |
| Red / Blue | — | — | — | X |
Checking Spark Safely
The Parsun service manuals describe spark testing with an ignition tester connected to the plug cap. Use a tester suitable for the ignition system and follow its connection and gap-setting instructions. Avoid testing with a loose spark plug held against the engine: it creates an exposed spark and leaves an open plug hole from which fuel vapour can escape.
- Prepare with the ignition off and the lanyard removed. Keep the spark plugs installed. Check for fuel leaks and vapour, secure the engine and select neutral. Keep everyone clear of the propeller. For a test in a tank, follow the owner's manual's propeller-removal and water-level instructions.
- Provide cooling water as specified in the owner's manual. The engine may start during the test, especially on a multi-cylinder engine. Do not crank or run the outboard dry.
- Connect the tester before enabling the ignition. Remove the cap from the plug being checked and connect it to the tester. Fit any required earth connection according to the tester instructions. Position the tester and leads clear of the flywheel and other moving parts.
- Restore power only when ready. If a starting battery was disconnected, reconnect it with the ignition off, positive first and negative last. Fit the lanyard and set the ignition for starting as described in the manual.
- Crank briefly and observe the tester's discharge window. Do not hold the cap, tester connections or high-voltage lead, and do not touch the ignition coil while the engine is turning. Observe the starter's cranking and rest limits in the owner's manual.
- Stop before changing the setup. Switch off the ignition and remove the lanyard before moving leads or disconnecting the tester. Disconnect the battery again before further wiring work. Refit the plug cap securely after testing.
A spark at the tester confirms ignition output under those test conditions; it does not prove that the spark plug fires correctly under compression. No spark can result from a stop-switch circuit, wiring, cap, coil, pulser or CDI fault. Check the manual's diagnostic sequence before ordering a replacement coil or CDI unit.
Charging and Rectifier Checks
A rectifier's DC output is a voltage measurement, not a resistance measurement. Check the battery, connections and charging equipment fitted to the engine before suspecting the rectifier or regulator.
Parsun supplies the following DC output values for the listed carburetor models:
| Model | Part number | Component | DC output |
|---|---|---|---|
| F9.9/F15 | F15-07060001 | Rectifier assembly | 13.5 V ±1 V |
| F20/F25 | F25-05170500W | Rectifier assembly | 13.5 V ±1 V |
Use the DC voltage meter setting and the test points, engine speed and load specified in the correct manual. Keep the required battery connections in place during the test; never disconnect a battery while the engine is running. Apply each figure to the listed component and prescribed test conditions.
CDI, pulser and ignition-charge-coil peak-voltage tests require the specified peak-voltage adaptor and procedure. Do not connect an ordinary multimeter directly to a spark-plug lead. Have a marine mechanic perform powered tests if you do not have the correct equipment or cannot identify the test points.
Manual References and Finding the Correct Part
Follow the procedures for your engine in these manuals:
- F2.6 service manual: spark testing and ignition checks.
- F4/F5 service manual: ignition testing and spark-plug cap checks.
- F9.9/F15 service manual: coil-test connections, with pulser testing under CDI inspection.
Once a fault is confirmed, use the parts catalog to match the model, diagram and part number. If specifications conflict or you cannot identify the fitted component, contact us with the full model designation, serial number, part number, photographs and your readings, including where you placed the probes and whether the plug cap was fitted.