Step‑by‑Step Guide to Basic Parsun 4‑Stroke Engine Maintenance

This guide covers the basic service tasks most owners can do themselves on a Parsun 4‑stroke outboard: engine oil, fuel filter, spark plugs and simple checks. For the complete overview, see How to maintain your Parsun outboard engine.

Always follow the safety instructions and torque values in your Parsun owner’s manual.

1. Checking and Changing Engine Oil

Engine oil is the lifeblood of your Parsun 4‑stroke.

  • Warm the engine briefly so the oil flows easily.
  • Stop the engine and keep it upright.
  • Check level with the dipstick (between min and max).
  • Drain old oil via the drain screw into a suitable container.
  • Replace the oil filter and drain plug gasket where fitted.
  • Refill with the recommended oil grade.

See the detailed instructions: Checking and changing engine oil.

2. Inspecting and Replacing Fuel Filters

Clean fuel prevents carburettor and injection problems.

  • On small engines (F9.8 and below), check the disposable filter inside the tank or fuel line.
  • On larger engines, inspect the serviceable filter in its cup and clean or replace it.
  • If you see water or dirt in the filter, clean the tank and fuel line.

Full guide: Inspecting and replacing fuel filters.

3. Cleaning or Replacing Spark Plugs

Good spark plugs give easy starting and smooth running.

  • Remove each plug and check colour and wear.
  • Clean or replace and set the correct gap (usually 0.6–0.9 mm, see manual).
  • Fit new plug gaskets and tighten to the specified torque.

Details and model links: Cleaning or replacing spark plugs.

4. Visual Checks: Propeller and Lower Unit

  • Remove the propeller and check for fishing line around the shaft.
  • Inspect blades for chips and bends.
  • Make sure the cotter pin and nut are in good condition.

For more advanced work (gear oil and impeller), see Advanced maintenance techniques for Parsun enthusiasts.

Order the Right Basic Service Parts

You’ll need the correct oil, oil filter, spark plugs, fuel filter and drain plug gaskets for your model. These are available in ready kits for Parsun 4‑stroke outboards:

We specialise in Parsun 4‑stroke outboards and ship parts quickly from Sweden.