Part of the Yanmar Operator Manuals.
Drain the gear oil from an SD20 leg and its color tells you at a glance whether the outer seal is still keeping the sea out, and this 33-page Yanmar operator manual tells you what to do about it either way. It covers the SD20, SD50, and SD50-4T sail drives, with the approved engine combinations listed inside: 1GM10C, 2YM15, 3YM20, 3YM30, 3JH4E, 4JH4E, and 4JH3-TCE.
Guessing is expensive on a sail drive. The wrong oil grade wears gears you cannot see, an under-torqued propeller nut costs you the prop, and a skipped diaphragm check ends with water where lubricant should be. This manual replaces the guess with Yanmar's own numbers: reduction ratios, oil capacities, propeller nut torque, and service intervals.
It also walks through first startup, the alarm system check, the cooling water routine, oil changes with the boat in or out of the water, and wiring diagrams for each instrument panel type.
Complete the set for your Yanmar Sail-Drive & Marine Engine Series
- Repair Manual: Yanmar SD40–SD50 Series Sail Drive Unit Service Manual
Other edition of this manual
What's Inside This Operator Manual
| System | Pages | Key Topics |
|---|---|---|
| Introduction | 3 | Sail-Drive Models, Engine Models, Engine and Sail-Drive Combinations |
| For Your Safety | 4-6 | Safety Precautions for Inspection |
| Specifications | 7 | Reduction Gear System, Direction of Rotation, Reduction Ratio, Propeller Speed, Lubrication System, Dry Weight |
| Selecting Lubricating Oil | 8-9 | Choice of Lube Oil, Kind of Lube Oil, Lube Oil Viscosity |
| Starting the New Sail-Drive for the First Time | 10-15 | Filling with Lubricating Oil (SD20 and SD50/-4T), Check of Instrument Panel Alarm System, Remote-Control Device Check, Fitting for Fixed Propeller, Recommended Propeller Size |
| Method of Operation | 16-17 | Engine Cooling Water (SD20, SD50/SD50-4T) |
| Periodic Inspections and Maintenance | 18-30 | Lubricating Oil System (SD20, SD50/-4T), Procedure for Filling and Removing Oil in the Sail-Drive; SD50/-4T (When Boat: in the Water, Out of the Water) |
| Electrical Wiring Diagrams | 31-33 | Color Coding, A-Type Instrument Panel, B-Type Instrument Panel, B X B-Type Instrument Panel, C X B-Type Instrument Panel, Cross Sectional Area |
Quick Reference Specifications
| Specification | Value | Page |
|---|---|---|
| SD20 | ||
| Propeller Nut Tightening Torque, SD20 | 60-70 Nm | p. 14 |
| Lube Oil Change Interval, SD20 | first 50 hours of operation or after long storage, and every 100 hours of operation thereafter | p. 19 |
| Reduction Ratio Ahead, SD20 | 2.64 | p. 7 |
| Lubrication Oil Capacity (Long-reach Unit) | 2.5 L | p. 7 |
| Dry Weight | 30 Kg | p. 7 |
| SD50/SD50-4T | ||
| Propeller Nut Tightening Torque, SD50/SD50-4T | 80-100 Nm | p. 14 |
| Lube Oil Change Interval, SD50/SD50-4T | first 50 hours of operation or after long storage, and every 250 hours of operation thereafter | p. 20 |
| SD20 and SD50/-4T | ||
| Rubber Diaphragm Seal Ring Replacement Interval | at least every 6 years | p. 18 |
| SD50, SD50-4T | ||
| Reduction Ratio Ahead (SD50, SD50-4T) | 2.32 | p. 7 |
| All Models | ||
| Lubrication Oil Capacity (Standard Unit) | 2.2 L | p. 7 |
| SD50 | ||
| Lubrication Oil Capacity (Long-reach Unit, Extension 58) | 2.35 L | p. 7 |
| SD50-4T | ||
| Lubrication Oil Capacity (Long-reach Unit, Extension 100) | 2.45 L | p. 7 |
