Honda Outboard Winterization Guide

The eight steps are the same for every outboard. What changes brand to brand is which fluids go in and a few details about how the engine is built. This is the Honda version. For the general walkthrough, start with the boat winterization guide.

What your Honda needs

Honda has been four stroke since the beginning

Which is worth saying out loud, because it means every Honda outboard on the water has a crankcase full of oil that needs changing before storage, and it means the oil change is not optional the way it is for a two stroke owner. Honda was doing four stroke outboards when nobody else was, and the engines last a long time if you keep the oil clean.

Fuel, before the last run

Add stabilizer to a nearly full tank and run the engine long enough that treated fuel gets all the way through the system.

If your BF is carbureted, drain the carburetor float bowls after the run. Most of the smaller and older Honda outboards are carbureted, and every one of them has a drain screw on the bowl for exactly this reason. Fuel left standing in a bowl for five months turns into varnish, and varnish in a Honda carb is a spring rebuild that a two minute job would have prevented. Some models also have a fuel shutoff you can close and then run the engine dry.

Then change the fuel filter.

Fog it, then new plugs

Fog it until it smokes and stalls, then install new plugs. In that order. Fogging fouls whatever plugs are in the engine, so a new set installed first is already spent by spring.

Oil and filter, warm

Change it right after the fogging run while it is still hot, so the water and acid come out with the oil rather than sitting in the crankcase until April. Honda BF engines want a Honda Marine FC-W oil in the weight your manual specifies, with a new Honda oil filter.

Lower unit, and the two gaskets everybody reuses

Pull the lower plug and read what comes out before you plan the refill. Clean gear oil is the color it went in. Milky means water got past a seal, and that is a repair to book now instead of finding in May. Glitter means wear inside.

Refill with Honda gear case oil from the bottom until it comes out the top, then close the top plug first.

Both plugs take a new sealing washer. Two cheap parts and the most skipped item on this list every year. Reusing crushed washers is how water gets into a gearcase over a winter. They are specific to your model, so send us your model and serial or call and we will match them.

Impeller

The impeller is a wear item on a schedule. Check what your manual says for your engine, then pick an end of the season and stay consistent.

The case for doing it in the fall is that you are already in the lower unit for the gear oil, and that an impeller sitting all winter with its vanes bent in one direction takes a set. If it was marginal in October it is worse in May, and the way you learn that is the overheat buzzer.

Buy the full water pump kit rather than the bare impeller. The wear plate, housing and seals in the kit are the reason people do this job twice.

Finish it

  • Grease the steering, the tilt tube and the prop shaft with marine grease
  • Check the anodes. More than half gone means replace now, not in the spring queue
  • Battery off the boat, terminals cleaned and coated, on a maintainer if you have one
  • Store the engine tilted all the way down so the gearcase drains
  • Cover it, and vent the cover

Not sure which oil or filter your BF takes? Call us at 631-722-5700 or send us your model and serial number. Always check your Honda owner's manual for capacities, the carburetor drain procedure and service intervals for your specific motor.