Routine & 100-Hour Annual Maintenance Checklist · Japan · all prices

No maker publishes sales figures. These lists are built from best-seller and most-reviewed proxies (retailer rankings, review volume, awards) over the last five years — the source is shown under each entry.

1. Yamalube 4-Stroke Marine Oil 10W-40 4L — ¥6,800
   Factory marine oil engineered in Japan; NMMA FC-W certified with exceptional shear stability.
2. Suzuki Genuine 4-Stroke Oil + Filter Kit — ¥8,500
   OEM maintenance pack designed for DF series outboards; includes crush washer and O-rings.
3. Tohatsu Genuine 100h Maintenance Pack — ¥7,900
   Official Tohatsu parts kit keeping warranty intact; includes primary and secondary filters.
4. Honda Ultra 4-Stroke Oil SJ 10W-30 — ¥6,200
   Clean burning marine oil formulated specifically for Honda VTEC and BLAST engines.
5. Easterner 10-Micron Fuel Water Separator — ¥5,800
   Clear bowl separator kit widely used on Japanese bass and rental boats to catch tank moisture.
6. Quicksilver High-Performance Gear Oil 946ml — ¥3,800
   Extreme pressure gear lubricant ensuring transmission safety even with emulsified water.
7. NGK Marine Iridium Plugs (Japan Spec) — ¥8,200
   Japanese domestic market iridium plugs delivering peak spark energy in cold mornings.
8. Yamaha Impeller Service Kit — ¥6,500
   Genuine neoprene water pump impeller ensuring optimal engine cooling block flow.
9. Wako's Fuel One Marine Additive — ¥2,400
   Japan's most trusted fuel additive; clears carbon deposits from injector nozzles quickly.
10. Salt-Away Engine Flush Mixer Kit — ¥6,900
    Essential freshwater mixer flushing out salt and minerals after coastal and brackish runs.