The goal

A disciplined spring routine catches winter damage at the dock instead of a mile offshore. Budget 1.5–2.5 hours for a single outboard; use this as your working checklist.

Fuel system first

• Inspect the fuel line end-to-end: cracked primer bulbs, hard hoses, weeping fittings. Ethanol-era hose that's stiff gets replaced, not trusted.
• Replace the water-separating fuel filter and any on-engine filters. Drain the old separator into a clear jar — water or gel means the tank needs attention before starting.
• Smell the fuel. Sour, varnish-smelling gas from last summer should be pumped out, not "run through."

Engine

• Check gear oil condition if it wasn't changed in fall (milky = stop, pressure test).
• Confirm engine oil level/condition on four-strokes; change it if it wasn't done at layup.
• New or cleaned/inspected spark plugs — check the service manual for the plug type and gap.
• Inspect the impeller/water pump if it's due (2 seasons or per manual).
• Grease all fittings, check anodes (replace past ~50% consumed), inspect the prop for dings and fishing line at the seal.

Electrical

• Load-test the battery, don't just voltage-check it. Clean and re-torque terminals; verify the battery switch and that the bilge pump float still has power with the switch off (if wired that way).
• Test nav lights, horn, gauges, and the kill lanyard — actually pull it while running.

Hull and trailer

• Drain plug IN — physically verify, make it the same ritual every time.
• Check the bilge pump by lifting the float; verify steering lock-to-lock is smooth; check trailer lights, straps, and bearings before the first tow.

First start

1. Muffs on with strong water flow, or launch and start at the ramp dock.
2. Confirm telltale within seconds, no alarms, oil pressure/charging on the gauges.
3. Short sea trial: verify shifts, full-throttle rpm in the range listed in the service manual, and no overheating after sustained cruise.

Common mistakes

• Starting on last year's untreated fuel "just to test"
• Skipping the lanyard and bilge pump tests — the two cheapest safety checks there are
• Forgetting the drain plug (put it on the invoice checklist so the customer sees it was verified)

When to walk away

If you find milky gear oil, mouse-chewed harnesses, or fuel gel, stop and re-quote before proceeding — spring surprises should change the estimate, not get buried.