Suzuki DF140 service guide

Quick answers

How much oil does a Suzuki DF140 take?

5.5 L (5.8/4.8 US/Imp. qt) oil change only; 5.7 L (6.0/5.0 US/Imp. qt) with filter change.

What engine oil does a Suzuki DF140 use?

API SE, SF, SG, SH or SJ, SAE 10W-40.

What gear oil does a Suzuki DF140 use, and how much?

Suzuki Outboard Motor Gear Oil (SAE #90 hypoid gear oil). Quantity: 1050 ml (35.5/37.0 US/Imp. oz).

What spark plug does a Suzuki DF140 use?

NGK BKR6E, resistor type only, qty 4. Gap: 0.7 to 0.8 mm (0.028 to 0.031 in).

How often should a Suzuki DF140 be serviced?

The factory schedule lists: Initial 20 hours or 1 month; Every 50 hours or 3 months; Every 100 hours or 6 months; Every 200 hours or 12 months. In Hawaiʻi's salt water we do a full yearly service every 200 hours or 1 year, whichever comes first, and a new engine needs its first (break-in) service.

When should the water pump impeller be replaced on a Suzuki DF140?

The factory schedule says to replace it at 200 hours, and we follow that. In any case we never let it go longer than a year in Hawaiʻi's salt water.

What is the idle speed of a Suzuki DF140?

700 ± 50 r/min, in gear about 700.

What is the propeller nut torque on a Suzuki DF140?

55 N·m (5.5 kg-m, 40.0 lb-ft).

Maintenance specs

Engine oil	API SE, SF, SG, SH or SJ, SAE 10W-40
Engine oil quantity	5.5 L (5.8/4.8 US/Imp. qt) oil change only; 5.7 L (6.0/5.0 US/Imp. qt) with filter change
Engine oil filter	14 N·m (1.4 kg-m, 10 lb-ft), 3/4 turn after the O-ring touches; oil filter stand 40 N·m (4.0 kg-m, 29 lb-ft)
Engine oil drain plug	13 N·m (1.3 kg-m, 9.5 lb-ft), new gasket
Gear oil	Suzuki Outboard Motor Gear Oil (SAE #90 hypoid gear oil)
Gearcase oil capacity	1050 ml (35.5/37.0 US/Imp. oz)
Gear oil drain and level plugs	13 N·m (1.3 kg-m, 9.5 lb-ft), new gaskets (standard and counter rotation gearcases)
Gearcase leak test	100 kPa (1.0 kg/cm², 14.2 psi) through the oil level hole, holding steady at least 5 minutes; start at 20 to 40 kPa (2.8 to 5.7 psi). Do not exceed 110 kPa (1.1 kg/cm², 15.6 psi)
Spark plug	NGK BKR6E, resistor type only, qty 4
Spark plug gap	0.7 to 0.8 mm (0.028 to 0.031 in)
Spark plug torque	28 N·m (2.8 kg-m, 20.0 lb-ft) (DF90/115 base procedure)
Idle speed	700 ± 50 r/min, in gear about 700
Thermostat operating temperature	58 to 62 °C (136 to 144 °F)
Anodes	Replace when 2/3 is gone; never paint; Suzuki Silicone Seal on the anode bolts.
Propeller nut	55 N·m (5.5 kg-m, 40.0 lb-ft)
Power trim and tilt fluid	Dexron automatic transmission fluid or equivalent (new 3 cylinder PTT unit); check tilted full up. Manual release valve 3.5 N·m (0.36 kg-m, 2.6 lb-ft)
Tappet clearance, cold	IN and EX 0.23 to 0.27 mm (0.009 to 0.011 in); left hand rotation powerhead, turn the crankshaft counterclockwise only

Service schedule

The factory maintenance intervals, with what is replaced and what is checked at each. Rows marked Hawaiʻi are our shop's yearly service for salt water use.

1. Initial 20 hours or 1 month

   Replace: engine oil, oil filter, oil drain plug gasket, gear case oil, gear case plug gaskets, propeller cotter pin

2. Every 50 hours or 3 months

   Replace: gear case plug gaskets

   Check: fuel filter, anodes

3. Every 100 hours or 6 months

   Replace: engine oil, oil drain plug gasket, gear case oil, gear case plug gaskets, propeller cotter pin

   Check: fuel filter, anodes

4. Every 200 hours or 12 months

   Replace: engine oil, oil filter, oil drain plug gasket, spark plugs, gear case oil, gear case plug gaskets, propeller cotter pin, water pump impeller

   Check: fuel filter, anodes

Source: Suzuki DF90/115 service manual 99500-90J07-03E; Suzuki DF140/140Z supplementary service manual 99501-92J00-01E. Specs can change by model year and serial number, so always confirm your exact model from the serial tag on the clamp bracket.