This chart collects the torque figures a Suzuki outboard owner actually reaches for: spark plugs, engine oil drain plug and filter, propeller nut, transom mounting bolts and clamp screws, plus the service-manual items people search for most (flywheel, gearcase bolts, water pump case, thermostat cover, clamp bracket shaft nut, tiller handle). Every figure comes from a Suzuki owner's, set-up or service manual and is printed the way Suzuki prints it.
Two things to know before you use it. First, Suzuki's owner's manuals give ranges (for example a propeller nut at 50 – 60 N·m) while the service and set-up manuals give a single figure (55 N·m). Where both exist we show both: the owner's-manual range is the figure written for owners, and the service or set-up figure is what the dealer manual prints. Second, a dash means the manual we have does not print that value; it does not mean there is no spec. Check the manual for your model year and serial number.
Spark plug, engine oil drain plug and oil filter
Spark plug torques come from both the owner's and the service manuals; drain plug and oil filter torques are only printed in the service manuals. The owner's manuals also give a rotation-angle alternative for the plug: seat it by hand, then a new plug 1/2 – 3/4 of a turn, a re-used plug 1/12 – 1/8 of a turn.
| Family (manuals used) | Spark plug, owner's manual | Spark plug, service manual | Engine oil drain plug | Engine oil filter |
|---|---|---|---|---|
| DF2.5 (owner's 2019; service 99500-97J01-01E) | 10 – 12 N·m (1.0 – 1.2 kg-m, 7.0 – 8.5 lb-ft) | 11 N·m (1.1 kg-m, 8.0 lb-ft) | 10 N·m (1.0 kg-m, 7.0 lb-ft) | — |
| DF4A / DF6A (owner's 2019) | 10 – 12 N·m (1.0 – 1.2 kgf-m, 7.4 – 8.9 lbf-ft) | — | — | — |
| DF4 / DF5 / DF6, earlier carbureted models (service 99500-91J03-01E) | — | 28 N·m (2.8 kg-m, 20.0 lb-ft) with NGK BPR6ES; 11 N·m (1.1 kg-m, 8.0 lb-ft) with NGK CPR6EA-9 from serial 110001 | 10 N·m (1.0 kg-m, 7.0 lb-ft) | — |
| DF8A / DF9.9A (owner's 2014; service 99500-99J00) | 1.0 – 1.2 kg-m (7.2 – 8.7 lb-ft), as printed | 11 N·m (1.1 kgf-m, 8.0 lbf-ft) | 13 N·m (1.3 kgf-m, 9.5 lbf-ft) | — |
| DF9.9B / DF15A / DF20A (owner's 2020 and 2014; service 99500-89L00-01E) | 10 – 12 N·m (1.0 – 1.2 kgf-m, 7.4 – 8.9 lbf-ft); the 2014 manual prints 1.0 – 1.2 kg-m (7.2 – 8.7 lb-ft) | 11 N·m (1.1 kgf-m, 8.0 lbf-ft) | 13 N·m (1.3 kgf-m, 9.5 lbf-ft) | Cap bolts "securely", no figure |
| DF25A / DF30A (owner's 2018; service 99500-94L10-01E) | 10 – 12 N·m (1.0 – 1.2 kg-m, 7.0 – 8.5 lb-ft) | 11 N·m (1.1 kgf-m, 8.0 lbf-ft) | 13 N·m (1.3 kgf-m, 9.5 lbf-ft) | 14 N·m (1.4 kgf-m, 10.0 lbf-ft), or 3/4 turn after the O-ring contacts |
| DF40A / DF50A / DF60A (owner's 2022; service DF60 99500-88L01-01E) | 15 – 19 N·m (1.5 – 1.9 kgf-m, 11 – 14 lbf-ft) | 17 N·m (1.7 kgf-m, 12 lbf-ft) | 13 N·m (1.3 kgf-m, 9.5 lbf-ft) | 14 N·m (1.4 kgf-m, 10.0 lbf-ft), or 3/4 turn |
| DF70A / DF75 / DF80A / DF90A / DF100B (owner's DF75/90A 2023; service 99500-87L10-01E) | 16 – 19 N·m (1.6 – 1.9 kgf-m, 12 – 14 lbf-ft) | 18 N·m (1.8 kgf-m, 13.0 lbf-ft) | 13 N·m (1.3 kgf-m, 9.5 lbf-ft) | 14 N·m (1.4 kgf-m, 10.0 lbf-ft), or 3/4 turn |
| DF100A / DF115A / DF140A (owner's 2016; service 99500-92J00-01E) | 25 – 28 N·m (2.5 – 2.8 kg-m, 18.1 – 20.0 lb-ft) | 28 N·m (2.8 kgf-m, 20.0 lbf-ft) | 13 N·m (1.3 kgf-m, 9.5 lbf-ft) | 14 N·m (1.4 kgf-m, 10.0 lbf-ft), 3/4 turn after O-ring contact |
| DF115B / DF140B (owner's 2023) | 15 – 19 N·m (1.5 – 1.9 kgf-m, 11 – 14 lbf-ft) | — | — | — |
| DF150A / DF175A / DF200A (owner's 2020) | 15 – 19 N·m (1.5 – 1.9 kgf-m, 11 – 14 lbf-ft) | — | — | — |
| DF150AP / DF175AP / DF200AP (owner's 2020) | 15 – 19 N·m (1.5 – 1.9 kgf-m, 11 – 14 lbf-ft) | — | — | — |
| DF225 / DF250 (owner's 2021) | 25 – 29 N·m (2.5 – 3.0 kgf-m, 18 – 21 lbf-ft) | — | — | — |
| DF250AP / DF300AP (owner's 2021) | 25 – 29 N·m (2.5 – 3.0 kgf-m, 18 – 21 lbf-ft) | — | — | — |
| DF300B / DF350A (owner's 2023) | 15 – 19 N·m (1.5 – 1.9 kgf-m, 11 – 14 lbf-ft); seat the plug by hand, then a new plug 1/2 – 3/4 of a turn, a re-used plug 1/12 – 1/8 of a turn | — | — | — |
The oil drain plug always goes back with a new gasket; the owner's manuals say "Do not re-use gaskets. Be sure to always use new gaskets." Capacities and the oil change procedure are on the oil capacity chart, and plug part numbers and gaps on the spark plug chart. None of the manuals we have prints a torque for the gear oil drain and level plugs; they only insist on new gaskets, because a used gasket may leak and let water into the gearcase.
Propeller nut, transom mounting bolts and clamp screws
Owner's manuals give the propeller nut as a range; set-up and service manuals give a single value. Mounting bolt torques come from the dealer set-up manuals (for the DF4A/6A, DF8A/9.9A, DF9.9B/15A/20A and DF25A/30A, from our notes on those manuals). Clamp-screw motors have no clamp-screw torque: the manuals say to tighten them alternately by hand, and every clamp-screw family from the DF4A up also has to be bolted through the transom.
| Family | Propeller nut, owner's manual | Propeller nut, service or set-up manual | Transom mounting bolts / nuts (set-up manual) | Clamp screws |
|---|---|---|---|---|
| DF2.5 | Not printed; tighten the nut and fit the cotter pin | — | Clamp screws only, plus a safety rope or cable to the clamp bracket hole | Tighten alternately by hand; check occasionally |
| DF4A / DF6A | Not printed; nut with cotter pin | — | M8 × 90 bolts (not included with the motor): 13 N·m (9.5 lb-ft) | 2-M10 × P1.5, by hand; the motor must also be bolted |
| DF8A / DF9.9A | 16 – 20 N·m (1.6 – 2.0 kg-m/12 – 14 lb-ft) | 18 N·m (1.8 kgf-m, 13.0 lbf-ft) service | M8 × 90 bolts: 13 N·m (9.5 lb-ft) | 2-M14 × P2.0, by hand; must also be bolted |
| DF9.9B / DF15A / DF20A | 16 – 20 N·m (1.6 – 2.0 kgf-m/12 – 15 lb-ft); 2014 manual prints 12 – 14 lb-ft | 18 N·m (1.8 kgf-m, 13.0 lbf-ft) service | M8 × 90 bolts: 13 N·m (9.5 lb-ft) | 2-M14 × P2.0, by hand; must also be bolted |
| DF25A / DF30A | 20 – 30 N·m (2.0 – 3.0 kg-m/14.5 – 21.5 lb-ft) | 25 N·m (2.5 kgf-m, 18.0 lbf-ft) service; 25 N·m (18 lb-ft) set-up | Tiller and R models, M10 × 110: 38 N·m (27.5 lb-ft). T/TH/Q models, four M12 × 100: 55 N·m (40 lb-ft) | 2-M14 × P2.0 on tiller/R, by hand; must also be bolted |
| DF40A / DF50A / DF60A | 50 – 60 N·m (5.1 – 6.1 kgf-m/37 – 44 lbf-ft) | 55 N·m (5.5 kgf-m, 40.0 lbf-ft) service; 55 N·m (5.6 kgf-m, 41 lbf-ft) set-up | Four M12 × 100 bolts with lock nuts: 55 N·m (5.6 kgf-m, 41 lbf-ft) | None, bolt-through only |
| DF70A / DF75 / DF80A / DF90A / DF100B | 50 – 60 N·m (5.1 – 6.1 kgf-m/37 – 44 lbf-ft) | 55 N·m (5.5 kgf-m, 40.0 lbf-ft) service; 55 N·m (5.5 kgf-m) set-up | Four M12 bolts: 55 N·m (5.6 kgf-m, 41 lbf-ft) | None |
| DF100A / DF115A / DF140A | 50 – 60 N·m (5.0 – 6.0 kg-m/36.0 – 43.5 lb-ft) | 55 N·m (5.5 kgf-m, 40.0 lbf-ft) service; 55 N·m (5.5 kgf-m) set-up | Four M12 × 115 bolts: 55 N·m (5.5 kgf-m, 40 lb-ft) | None |
| DF115B / DF140B | 50 – 60 N·m (5.1 – 6.1 kgf-m/37 – 44 lbf-ft) | 55 N·m (5.6 kgf-m, 41 lbf-ft) set-up | Four M12 bolts: 55 N·m (5.6 kgf-m, 41 lbf-ft) | None |
| DF150A / DF175A / DF200A | 50 – 60 N·m (5.1 – 6.1 kgf-m/37 – 44 lbf-ft) | 55 N·m (5.5 kgf-m) set-up | 1/2-20 UNF bolts with nylon-insert lock nuts: 80 N·m, printed as (8.0 kgf-m, 58.0 lbf-ft) on one page and (8.2 kgf-m, 59 lbf-ft) on another. Six bolts recommended for rigid-hull inflatables; four-bolt method needs a reinforcement plate | None |
| DF150AP / DF175AP / DF200AP | 50 – 60 N·m (5.1 – 6.1 kgf-m/37 – 44 lb-ft) | 55 N·m (5.5 kgf-m, 40 lbf-ft) set-up | 80 N·m (8.0 kgf-m, 58.0 lbf-ft) / (8.2 kgf-m, 59 lbf-ft), both as printed | None |
| DF225 / DF250 | 50 – 60 N·m (5.1 – 6.1 kgf-m/37 – 44 lbf-ft) | — | — | None |
| DF250AP / DF300AP | 50 – 60 N·m (5.1 – 6.1 kgf-m/37 – 44 lbf-ft) | 55 N·m (5.5 kgf-m, 40 lb-ft) set-up | 1/2-20 UNF bolts, nylon-insert lock nuts: 80 N·m (8.2 kgf-m, 59 lbf-ft); also printed (8.0 kgf-m, 58.0 lb-ft). Six bolts recommended for rigid-hull inflatables; the four-bolt method needs a transom reinforcement plate | None |
| DF300B / DF350A (dual prop) | Front nut 125 – 135 N·m (13 – 14 kgf-m/92 – 100 lbf-ft), left-hand thread; rear nut 50 – 60 N·m (5.1 – 6.1 kgf-m/37 – 44 lbf-ft) | Front 130 N·m (13 kgf-m, 96 lbf-ft); rear 55 N·m (5.6 kgf-m, 41 lbf-ft) set-up | Six 1/2-20 UNF bolts: 80 N·m (8.2 kgf-m, 59 lbf-ft) | None |
The propeller install sequence and the prop sizes for each family are on the propeller chart; the transom-height, hole-drilling and sealant details are in the mounting guide. On the DF300B/DF350A the front nut is left-hand thread and needs the Suzuki "Propeller nut remover & installer"; the set-up manual calls the tool 09923-29810.
Service-manual items: flywheel, gearcase, water pump, thermostat, clamp bracket, tiller
These are the fasteners you meet during an impeller or thermostat job or a lower-unit reseal. They come from the service manuals we have, which stop at the DF140A; trim tab bolt figures are from the set-up manuals.
| Family (service manual) | Flywheel nut / bolt | Gearcase bolts | Water pump case | Thermostat cover | Clamp bracket shaft nut | Tiller handle |
|---|---|---|---|---|---|---|
| DF2.5 (99500-97J01-01E) | Nut 45 N·m (4.5 kg-m, 32.5 lb-ft) | 8 N·m (0.8 kg-m, 6.0 lb-ft) | Bolt 5 N·m (0.5 kg-m, 3.5 lb-ft) | — | — | Pivot bolt 17 N·m (1.7 kg-m, 12.5 lb-ft) |
| DF4 / DF5 / DF6 (99500-91J03-01E) | Nut 50 N·m (5.0 kg-m, 36.0 lb-ft) | 17 N·m (1.7 kg-m, 12.5 lb-ft) | Nut 8 N·m (0.8 kg-m, 6.0 lb-ft) | Thermostat sits under the intake manifold; manifold bolts 10 N·m (1.0 kg-m, 7.0 lb-ft) | 25 N·m (2.5 kg-m, 18.0 lb-ft) | Pivot bolt 12 N·m (1.2 kg-m, 8.5 lb-ft); pivot nut 17 N·m (1.7 kg-m, 12.5 lb-ft) |
| DF8A / DF9.9A (99500-99J00) | Nut 78.4 N·m (7.9 kgf-m, 57.0 lbf-ft) | 17 N·m (1.7 kgf-m, 12.3 lbf-ft) | Nut 6 N·m (0.6 kgf-m, 4.3 lbf-ft) | 23 N·m (2.3 kgf-m, 16.5 lbf-ft), 8 mm bolt | R models 43 N·m (4.3 kgf-m, 31.0 lbf-ft); tiller models 50 N·m (5.0 kgf-m, 36.0 lbf-ft) | Cover bolt 17 N·m (1.7 kgf-m, 12.5 lbf-ft) |
| DF9.9B / DF15A / DF20A (99500-89L00-01E) | Nut 90 N·m (9.0 kgf-m, 65 lbf-ft) | 17 N·m (1.7 kgf-m, 12.3 lbf-ft) | Nut 6 N·m (0.6 kgf-m, 4.3 lbf-ft) | 10 N·m (1.0 kgf-m, 7.2 lbf-ft) | 43 N·m (4.3 kgf-m, 31.0 lbf-ft) | Cover bolt 23 N·m (2.3 kgf-m, 16.5 lbf-ft) |
| DF25A / DF30A (99500-94L10-01E) | Nut 100 N·m (10.0 kgf-m, 72.5 lbf-ft) | 23 N·m (2.3 kgf-m, 16.5 lbf-ft) | Nut 6 N·m (0.6 kgf-m, 4.3 lbf-ft) | 11 N·m (1.1 kgf-m, 8.0 lbf-ft) | 43 N·m (4.3 kgf-m, 31.0 lbf-ft); revised to 52 N·m (5.3 kgf-m, 38.3 lbf-ft) for serial 540001 and later (2024/06 supplement) | Cover bolt 23 N·m (2.3 kgf-m, 16.5 lbf-ft) |
| DF40A / DF50A / DF60A (DF60 manual 99500-88L01-01E) | Bolt 166 N·m (16.6 kgf-m, 120.0 lbf-ft) | 23 N·m (2.3 kgf-m, 16.6 lbf-ft) | Nut 8 N·m (0.8 kgf-m, 5.8 lbf-ft) | 10 N·m (1.0 kgf-m, 7.2 lbf-ft) | 43 N·m (4.3 kgf-m, 31.0 lbf-ft) | Mounting bolt 50 N·m (5.0 kgf-m, 36.0 lbf-ft); pivot bolt 25 N·m (2.5 kgf-m, 18.0 lbf-ft); pivot nut 45 N·m (4.5 kgf-m, 32.0 lbf-ft) |
| DF70A / DF75 / DF80A / DF90A / DF100B (99500-87L10-01E) | Bolt 196 N·m (19.7 kgf-m, 142.0 lbf-ft), left-hand thread | 55 N·m (5.5 kgf-m, 40.0 lbf-ft) | Bolt 17 N·m (1.7 kgf-m, 12.3 lbf-ft) | 10 N·m (1.0 kgf-m, 7.0 lbf-ft); the procedure page prints 7.2 lbf-ft | 43 N·m (4.3 kgf-m, 31.0 lbf-ft) | Bracket bolt 50 N·m (5.0 kgf-m, 36.0 lbf-ft), set-up manual |
| DF100A / DF115A / DF140A (99500-92J00-01E) | Bolt 245 N·m (24.5 kgf-m, 177.0 lbf-ft) | 54 N·m (5.5 kgf-m, 40.0 lbf-ft) | Bolt 17 N·m (1.7 kgf-m, 12.5 lbf-ft) | 10 N·m (1.0 kgf-m, 7.0 lbf-ft) | 43 N·m (4.3 kgf-m, 31.0 lbf-ft) | — |
Trim tab bolt, from the set-up manuals: 23 N·m (2.3 kgf-m, 17 lbf-ft) on the DF40A–60A, DF115B/140B and DF150A–200A; 23 N·m (2.4 kgf-m, 17 lbf-ft) as printed on the DF150AP–200AP and DF250AP/300AP. The full impeller and thermostat procedures, with these torques in context, are in impeller and thermostat replacement.
General bolt torque when no figure is listed
Every Suzuki service manual we have prints the same general table for bolts that are not in its "Important Fasteners" list, and the DF9.9B/15A/20A manual adds that these values apply only when a torque for the bolt is not listed there. The bolt head marking tells you which column to use.
| Thread | Conventional or "4" marked bolt | Stainless steel bolt | "7" marked bolt |
|---|---|---|---|
| 5 mm | 2 – 4 N·m (1.5 – 3.0 lb-ft) | 2 – 4 N·m (1.5 – 3.0 lb-ft) | 3 – 6 N·m (2.0 – 4.5 lb-ft) |
| 6 mm | 4 – 7 N·m (3.5 – 5.0 lb-ft; the DF2.5 and DF4/5/6 manuals print 3.0 – 5.0) | 6 – 10 N·m (4.5 – 7.0 lb-ft) | 8 – 12 N·m (6.0 – 8.5 lb-ft) |
| 8 mm | 10 – 16 N·m (7.0 – 11.5 lb-ft) | 15 – 20 N·m (11.0 – 14.5 lb-ft) | 18 – 28 N·m (13.0 – 20.0 lb-ft) |
| 10 mm | 22 – 35 N·m (16.0 – 25.5 lb-ft) | 34 – 41 N·m (24.5 – 29.5 lb-ft) | 40 – 60 N·m (29.0 – 43.5 lb-ft) |
Torque-wrench notes from the manuals
- Transom nuts: no impact tools, and lock nuts are single use. The set-up manuals say not to use an impact tool to tighten or loosen the transom nuts, and never to reuse the lock nut after it has been threaded into position and torqued. To get an accurate torque, hold the bolt and turn the nut. Sealant (Suzuki Silicone Seal or equivalent) goes in all bolt holes and on the shanks of the bolts, but not the threads. If the specified torque cannot be reached because the transom material is weak, a reinforcement plate may be needed.
- Re-torque after break-in. After completing break-in operation (10 hours), retighten the transom nuts to the specified torque, and check the nuts periodically. The DF25A/30A set-up notes carry the same instruction for the bolted T/TH/Q models.
- Clamp screws are hand-tight. Center the motor and tighten the clamp bracket screws alternately by hand. On the DF4A/6A, DF8A/9.9A, DF9.9B/15A/20A and DF25A/30A the owner's manual adds: "Be sure to bolt the motor to the transom. The motor may come off if it is held only by the clamp screws. Occasionally check the clamp screws for tightness." The DF4A/6A manual also warns that over-tightening the transom bolts can damage the clamp bracket.
- Spark plugs. If you have no torque wrench, use the rotation-angle method printed in the owner's manuals: a new plug 1/2 – 3/4 of a turn after seating, a re-used plug 1/12 – 1/8 of a turn.
- Oil filter. The service manuals give 14 N·m, but the procedure they describe is to screw the filter on by hand until the O-ring contacts the mounting surface, then tighten it 3/4 turn with an oil filter wrench.
- Gaskets and cotter pins are new every time. Drain plugs get a new gasket. The DF2.5 service manual sums up the lower unit rule: do not re-use the gasket, the O-ring and the cotter pin once removed; always use new parts. After torquing the propeller nut, align the grooves in the nut with the hole in the shaft, insert the cotter pin and bend the ends over to lock it.
- Left-hand threads. The flywheel bolt on the DF70A–DF100B is a left-hand thread, and so is the front propeller nut on the DF300B/DF350A.
- Serial-number revisions. Suzuki revises figures with supplements: the DF25A/30A clamp bracket shaft nut went from 43 N·m to 52 N·m for serial 540001 and later, and the DF4/5/6 spark plug torque dropped from 28 N·m to 11 N·m when the plug changed at serial 110001. Match the figure to your serial number.
Parts for this job
For an oil change, the Suzuki oil change kits include the filter and drain gasket for your family. Plugs are under NGK spark plugs by model, propeller nuts, washers, spacers and cotter pins under propeller hardware, and mounting bolt kits under rigging hardware and fasteners. We are an authorized Suzuki, Honda and Yamaha dealer; orders over $149 ship free to the lower 48.
Sources: Suzuki owner's manuals for DF2.5, DF4A/6A, DF8A/9.9A, DF9.9B/15A/20A (2014 and 2020), DF25A/30A, DF40A/50A/60A, DF75/90A, DF100A/115A/140A, DF115B/140B, DF150A/175A/200A, DF150AP/175AP/200AP, DF225/250, DF250AP/300AP and DF300B/350A (99011-98L60-03B); Suzuki service manuals 99500-97J01-01E, 99500-91J03-01E, 99500-99J00, 99500-89L00-01E, 99500-94L10-01E, 99500-88L01-01E, 99500-87L10-01E and 99500-92J00-01E; Suzuki set-up manuals 99505-88L40-01E, 99505-87L50-01E, 99505-92J20-01E, 99505-99L40-01E, 99505-96L60-01E, 99505-96L70-01E, 99505-98J40-01E and 99505-98L40-01E, plus our notes from the DF4A/6A, DF8A/9.9A, DF9.9B/15A/20A and DF25A/30A set-up manuals. Figures are Suzuki's published values; confirm against the manual for your model year and serial number.