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 Suzuki version. For the general walkthrough, start with the boat winterization guide.
What your Suzuki needs
- Suzuki fuel additives
- Fogging oil
- Spark plugs
- Suzuki 4-stroke engine oil
- Suzuki oil filters
- Suzuki fuel filters and water separators
- Suzuki gear oil
- Suzuki water pump and impeller kits
- Marine grease
- Suzuki anodes
Use the fresh water flush port
Suzuki builds a fresh water flush connection into most of the DF range, and it works with the engine shut off. It is one of the genuinely nice things about owning a Suzuki and a lot of owners never touch it. Salt sitting in cooling passages for five months does real damage, so flush until what comes out is clean before you do anything else.
Fuel, before the last run
Add stabilizer to a nearly full tank and run the engine long enough that treated fuel reaches the water separating filter and the injectors. A Suzuki four stroke is fuel injected across most of the modern range, and injectors do not like sitting in untreated ethanol gas.
Then change the fuel filter. If your boat has a separate water separating canister filter in the rigging, do that one too.
Fog it, then new plugs
Fog it through the intake until it smokes and stalls, then install new plugs. In that order. Fogging fouls whatever plugs are in the engine, so new plugs installed first are already spent by spring.
Oil and filter, warm
Change it immediately after the fogging run, while the oil is still hot and carries the water and acid out with it. Suzuki DF engines want a Suzuki FC-W marine oil in the weight your manual calls for, with a new Suzuki oil filter.
Suzuki has been four stroke only for a long time, so if you are running an older two stroke Suzuki, skip this step and check your TC-W3 supply instead.
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 past a seal and that is a repair to book now rather than discover in May. Glitter means wear inside.
Refill with Suzuki gear oil from the bottom until it comes out the top level hole, then close the top plug first.
Both plugs take a new gasket. Two washers, a couple of dollars, and the most skipped item on this list every year. Reusing crushed gaskets is exactly 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, not a lifetime part. Read what your manual says for your engine and hold to it.
Fall or spring both work. The case for 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 takes a set. A marginal one in October is worse in May, and you find that out with an overheat alarm.
Buy the full water pump kit, not the bare impeller. The wear plate, housing and seals are why 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 weight or filter your DF takes? Call us at 631-722-5700 or send us your model and serial number. Always check your Suzuki owner's manual for capacities and service intervals for your specific motor.