The shrink wrap is off, the batteries came home in November and spent the winter on a maintainer, and the F25 kicker and the F200 main engine on a 25-foot walkaround are about to turn over for the first time since October. This is the morning that decides whether your first trip is a fishing day or a day in the parking lot with the cowling off. A few minutes with a scan before and after the first start take a lot of guessing out of it.
Before you turn the key
Batteries first. Install them, clean the terminals, and with the M-JET DIAGNOSTIC connected, check battery voltage with the key on. A battery that looks good on the maintainer can still sag hard under a cold crank, so watch the value during the first start too.
Then read the fault memory, before anything gets cleared and before the engine runs. Entries from last fall or from storage are useful. A battery voltage entry from a crank on a weak battery in the fall explains itself. An entry for a sensor you've never had trouble with is worth a note, because winter storage in a damp shed is when connectors start growing green crust.
While you're there, check the engine shut-off switch state. If the lanyard clip went missing over the winter or got stuffed in a drawer, this is where you find out, before the starter clicks and nothing happens.
Prime the fuel system properly
After a winter with stabilized fuel, the engine's fuel system still has air in it if filters were changed. The actuator tests on many engines include the electric fuel pump and on some the low-pressure pump. Running the pump for a few seconds through the app fills the system without cranking the starter for ages. Listen for the pump and check for leaks at the filter you just changed. A fuel smell under the cowling now is easy to fix. On the water it isn't.
The first run, on muffs or in the water
Watch the tell-tale first. Then, depending on what your engine reports, put engine temperature, cooling water pressure and oil pressure on one screen and let it warm up.
- Oil pressure should come up quickly after start. If the engine shows a pressure value, note it at warm idle.
- Temperature should climb steadily to operating range and settle once the thermostat opens. Very slow warm-up or none at all, with an overcooling entry later, means a thermostat stuck open.
- Cooling water pressure on muffs isn't comparable to running in the water. Use it only as "there or not there". Your real baseline comes from the first run on the water.
- Battery voltage with the engine running should rise clearly above the key-on reading.
Shift, trim and the rest
Run the trim through its full travel and watch the trim sensor value change smoothly. Shift gently into gear and back, on a boat that's in the water or tied up securely. If you have digital shift, glance at neutral judgement once the lever is back in neutral.
After the first real trip
Read the memory again. Anything that came back after a clean start in the driveway is a real issue. Then screenshot the engine hours and the live values at 2000 and 3000 rpm in gear while you have a calm day. Those are the numbers you'll compare against in August. The spring commissioning checklist covers the full routine with the mechanical items, and the live data page explains each value in more depth. On a boat with a kicker, do the kicker too. It's the engine you'll need on the day the main one has a problem.
