Suzuki Outboard Valve Clearance (Tappet / Valve Lash) Chart by Model, Plus Inspection Interval and Adjustment Method

Suzuki DF4A tiller outboard beside the title Valve Clearance Chart

Boat Max Online Service Team |

Valve clearance (Suzuki's manuals call it tappet clearance or valve lash) is the small gap between each valve and the rocker arm or cam follower that opens it, measured with the engine cold. Suzuki's 2025 four-stroke maintenance manual prints the figure for every family from the DF2.5 to the DF350A under one heading, "Tappet clearance (Valve lash) (Cold engine condition) (mm)", and the first chart below reproduces that table: intake and exhaust clearance in millimeters, by model and model year. The second chart adds what the service manuals and owner's manuals say for the families we hold manuals for: adjustment type, inspection interval, lock nut torque and head cover bolt torque.

Every figure is for a cold engine. And in the Suzuki owner's manuals we have for the DF2.5, DF4A/6A, DF8A/9.9A, DF9.9B/15A/20A, DF40A/50A/60A, DF100A/115A/140A, DF115B/140B, DF150A/175A/200A (A and AP), DF225/250, DF250AP/300AP and DF300B/350A, valve lash (some of them print it as valve clearance or tappet clearance) is an asterisked item in the maintenance chart. The DF2.5 and DF4A/6A manuals spell out what the asterisk means: "Suzuki recommends that only your authorized Suzuki marine dealer or a qualified service mechanic perform maintenance on those items in the chart above which are marked with an asterisk." The portables we hold service manuals for (DF2.5, DF4/5/6, DF8A/9.9A, DF9.9B/15A/20A and DF25A/30A) use a screw-and-lock-nut adjuster, so the service manual procedure needs a feeler gauge and hand tools. The DF40A/50A/60A and every larger family we hold a service manual for, up to the DF300B/325A/350A, use shims, which means the shim thickness has to be measured and a replacement calculated: dealer work. If the motor is under warranty, check with your dealer before opening the cylinder head cover.

Suzuki valve clearance chart, DF2.5 to DF350A (2025 maintenance manual)

Figures are in millimeters as printed; the 2025 manual prints no inch equivalents in this table. "2006 on" means the 2006 model year and later. Where the manual's layout made a row hard to read in the copy we have, the row says so: confirm against the service manual for your serial number. The Note column also marks the rows that a Suzuki service manual in our library confirms. One row, the DF200A/DF200AP, is filled in from the service manual instead, and its note says so.

Model Model years Intake (mm) Exhaust (mm) Note
DF2.5 2006 on 0.13 – 0.17 0.13 – 0.17 Matches the DF2.5 service manual
DF4 / DF5 / DF6 (earlier models, not the A series) 2002 – 2015 0.03 – 0.07 0.03 – 0.07 Printed once beside the 2005 – 2010 range and read as covering all three year ranges; the DF4/5/6 service manual gives the same figure
DF4A / DF5A / DF6A 2017 on 0.13 – 0.17 0.13 – 0.17
DF8A / DF9.9A 2006 on 0.16 – 0.20 0.16 – 0.20 Matches the DF8A/DF9.9A service manual
DF9.9 / DF15 2000 – 2004 0.08 – 0.12 0.13 – 0.17 Row flagged in our extraction (the pressure columns interleave); confirm in your manual
DF9.9 / DF15 2005 – 2012 0.18 – 0.22 0.18 – 0.22 Row flagged in our extraction; confirm in your manual
DF9.9B / DF15A / DF20A 2013 on 0.18 – 0.22 0.18 – 0.22 Matches the DF9.9B/15A/20A service manual
DF25 (V2) 2006 – 2014 0.03 – 0.07 0.03 – 0.07
DF25 / DF30 2006 – 2010 0.13 – 0.17 0.13 – 0.17
DF25A / DF30A 2015 on 0.18 – 0.22 0.20 – 0.24 Matches the DF25A/30A service manual
DF40 / DF50 2000 – 2010 0.18 – 0.22 0.18 – 0.22
DF40A / DF50A / DF60A / DF50AV / DF60AV 2010 on 0.18 – 0.22 0.28 – 0.32 Matches the DF40A/DF50A/DF60A service manual, which also covers the DF50AV/DF60AV
DF60 / DF70 2000 – 2009 0.11 – 0.15 0.13 – 0.17
DF70A / DF80A / DF90A / DF100B 2009 on 0.23 – 0.27 0.30 – 0.34 Matches the DF70A – DF100B service manual (which also covers the DF75)
DF90 / DF100 / DF115 2001 – 2012 0.23 – 0.27 0.23 – 0.27 Shares one printed row with the DF140
DF140 2002 – 2012 0.23 – 0.27 0.23 – 0.27
DF100A / DF115A / DF140A 2013 on 0.23 – 0.27 0.23 – 0.27 Matches the DF100A/115A/140A service manual
DF100C / DF115B / DF140B 2022 on 0.23 – 0.27 0.33 – 0.37 Shares one printed row with the DF115BG/140BG; matches the DF100C/DF115B/DF140B service manual
DF115BG / DF140BG 2021 on 0.23 – 0.27 0.33 – 0.37
DF150 / DF175 2006 on 0.23 – 0.27 0.30 – 0.34
DF150TG / DF175TG 2014 – 2016 0.23 – 0.27 0.30 – 0.34
DF150A / DF175A 2019 on 0.23 – 0.27 0.30 – 0.34 Printed as one group with the DF150AP/175AP; matches the DF150A/DF175A/DF200A service manual
DF150AP / DF175AP 2017 on 0.23 – 0.27 0.30 – 0.34 Matches the DF150A/DF175A/DF200A service manual, which covers the AP models
DF200A / DF200AP 2015 on 0.23 – 0.27 0.30 – 0.34 From service manual 99500-96L30-01E, which prints these for the DF200A and DF200AP; in our 2025 manual copy the model name prints between two rows
DF200 / DF225 / DF250 2004 on 0.23 – 0.27 0.33 – 0.37 Matches the DF200/DF225/DF250 service manual
DF300 2007 – 2011 0.23 – 0.27 0.33 – 0.37 Matches the DF300, DF250AP/DF300AP service manual
DF250AP / DF300AP 2012 on 0.23 – 0.27 0.33 – 0.37 Matches the DF300, DF250AP/DF300AP service manual
DF300B / DF325A 2020 on 0.23 – 0.27 0.33 – 0.37 Matches the DF300B/DF325A/DF350A service manual
DF350A 2018 on 0.23 – 0.27 0.33 – 0.37 The DF350A lines print no lash of their own in the 2025 manual; the DF300B/DF325A/DF350A service manual prints these figures for the DF350A

Adjustment type, interval and torques by family (service and owner's manuals)

This table covers only the families we hold a Suzuki service manual for. Inch figures are the service manual's own conversions. The earlier DF9.9/15, DF25 (V2), DF25/30, DF40/50, DF60/70, DF90/100/115 and DF140, and the DF150/175 and DF150TG/175TG appear only in the chart above: their adjustment method and interval are not stated in the manuals we have. The DF115BG/140BG has no service manual in our library either; its owner's manual (prepared July 2021) lists valve lash as a dealer item (asterisk) with one inspection mark, under the every 300 hrs. column.

Family (service manual) Clearance, cold, IN / EX Adjustment type Inspection interval Lock nut torque Cylinder head cover bolt torque
DF2.5 (99500-97J01-01E) IN and EX 0.13 – 0.17 mm (0.005 – 0.007 in) Adjusting screw and lock nut on the rocker arm Initially after 20 hours (1 month) and every 200 hours (12 months). Dealer item (asterisk) in the 2019 owner's manual 7 N·m (0.7 kg-m, 5.0 lb-ft) 7 N·m (0.7 kg-m, 5.0 lb-ft), four bolts, diagonally
DF4 / DF5 / DF6, earlier models (99500-91J03-01E) IN 0.03 – 0.07 mm (0.001 – 0.003 in); EX 0.03 – 0.07 mm (0.001 – 0.003 in) Pivot nut and lock nut on the rocker arm Initially after 20 hours (1 month) and every 200 hours (12 months) 11 N·m (1.1 kg-m, 8.0 lb-ft) 8 N·m (0.8 kg-m, 6.0 lb-ft)
DF4A / DF5A / DF6A (no service manual in our library) IN and EX 0.13 – 0.17 mm (2025 maintenance manual) Not stated in the manuals we have Dealer item (asterisk) with two inspection marks in the 2020 – 2024 owner's manual; which columns they fall in does not read cleanly in our copy Not stated Not stated
DF8A/DF9.9A (99500-99J00-01E) IN 0.16 – 0.20 mm (0.006 – 0.008 in.); EX 0.16 – 0.20 mm (0.006 – 0.008 in.) Adjusting screw and lock nut on the rocker arm; the manual lists valve adjustment driver 09917-14910 Initially after 20 hours (1 month) and every 200 hours (12 months). Dealer item (asterisk) at the same two marks in the 2014 owner's manual 11 N·m (1.1 kgf-m, 8.0 lbf-ft) 10 N·m (1.0 kgf-m, 7.2 lbf-ft)
DF9.9B / DF15A / DF20A (99500-89L00-01E) IN 0.18 – 0.22 mm (0.007 – 0.009 in); EX 0.18 – 0.22 mm (0.007 – 0.009 in) Adjusting screw and lock nut (the manual lists a "valve adjusting lock nut") Initially after 20 hours (1 month) and every 200 hours (12 months). Dealer item (asterisk) in the 2020 owner's manual 11 N·m (1.1 kgf-m, 8.0 lbf-ft) 10 N·m (1.0 kgf-m, 7.2 lbf-ft)
DF25A / DF30A (99500-94L10-01E) IN 0.18 – 0.22 mm (0.007 – 0.009 in); EX 0.20 – 0.24 mm (0.008 – 0.009 in) Adjusting screw and lock nut (the manual lists a "valve adjusting screw lock nut") Initially after 20 hours (1 month) and every 200 hours (12 months) 11 N·m (1.1 kgf-m, 8.0 lbf-ft) 10 N·m (1.0 kgf-m, 7.2 lbf-ft)
DF40A/DF50A/DF60A (99500-88L11-01E) IN 0.18 – 0.22 mm (0.007 – 0.009 in); EX 0.28 – 0.32 mm (0.011 – 0.013 in) Shim: IN A = B + (C – 0.20 mm), EX A = B + (C – 0.30 mm) Procedure page: every 200 hours (12 months); charts from serial 310001: every 300 hrs. or 36 months. Asterisked, one mark, in the 2022 owner's manual None (shim type) 11 N·m (1.1 kgf-m, 8.1 lbf-ft)
DF70A / DF75 / DF80A / DF90A / DF100B (99500-87L10-01E) IN 0.23 – 0.27 mm (0.009 – 0.011 in); EX 0.30 – 0.34 mm (0.012 – 0.013 in) Shim: IN A = B + (C – 0.25 mm), EX A = B + (C – 0.32 mm) Every 300 hours (36 months) per the service manual. The 2023 DF75/DF90A owner's manual prints the same clearances in its specification table; its schedule rows do not read cleanly in our copy None (shim type) 11 N·m (1.1 kgf-m, 8.0 lbf-ft)
DF100A / DF115A / DF140A (99500-92J00-01E) IN 0.23 – 0.27 mm (0.009 – 0.011 in); EX 0.23 – 0.27 mm (0.009 – 0.011 in) Shim: IN and EX A = B + (C – 0.25 mm) Every 300 hours (36 months) in both the service manual and the 2016 owner's manual, where it is a dealer item (asterisk) None (shim type) 11 N·m (1.1 kgf-m, 8.0 lbf-ft)
DF100C/DF115B/DF140B (99500-99L10-01E) IN 0.23 – 0.27 mm (0.009 – 0.011 in.); EX 0.33 – 0.37 mm (0.013 – 0.015 in.) Shim: IN A = B + (C – 0.25 mm), EX A = B + (C – 0.35 mm) Every 300 hours (36 months). Dealer item (asterisk) with one inspection mark in the DF115B/DF140B owner's manual None (shim type) 11 N·m (1.1 kgf-m, 8.1 lbf-ft)
DF150A/DF175A/DF200A, A and AP (99500-96L30-01E) IN 0.23 – 0.27 mm (0.009 – 0.011 in.); EX 0.30 – 0.34 mm (0.012 – 0.013 in.) Shim: IN A = B + (C – 0.25 mm), EX A = B + (C – 0.32 mm) Every 300 hours (36 months). Dealer item (asterisk) with one inspection mark in the 2023 (A) and 2019 (AP) owner's manuals None (shim type) 11 N·m (1.1 kgf-m, 8.0 lbf-ft), tightened in ascending order of the numbers
DF200/DF225/DF250 (99500-93J05-01E) IN 0.23 – 0.27 mm (0.009 – 0.011 in.); EX 0.33 – 0.37 mm (0.013 – 0.015 in.) Shim: IN A = B + (C – 0.25 mm), EX A = B + (C – 0.35 mm) Base procedure: initially after 20 hours (1 month) and every 200 hours (12 months); later pages change it, see the notes below None (shim type) 11 N·m (1.1 kg-m, 8.0 lb-ft)
DF300, DF250AP/DF300AP (99500-98J02-01E) IN 0.23 – 0.27 mm (0.009 – 0.011 in.); EX 0.33 – 0.37 mm (0.013 – 0.015 in.) Shim: IN A = B + (C – 0.25 mm), EX A = B + (C – 0.35 mm) Every 200 hours (12 months). Dealer item (asterisk) with one inspection mark in the 2021 DF250AP/DF300AP owner's manual None (shim type) 11 N·m (1.1 kg-m, 8.0 lb-ft)
DF300B/DF325A/DF350A (99500-98L10-01E) IN 0.23 – 0.27 mm (0.009 – 0.011 in.); EX 0.33 – 0.37 mm (0.013 – 0.015 in.) Shim: IN A = B + (C – 0.25 mm), EX A = B + (C – 0.35 mm) Every 300 hours (36 months). Dealer item (asterisk) with one inspection mark in the 2022 DF300B/DF350A owner's manual None (shim type) 11 N·m (1.1 kgf-m, 8.0 lbf-ft)

The intervals line up with Suzuki's wider schedule: the screw-type portables get a 20-hour first check and then a 200-hour cycle, and most of the shim engines from the DF70A up go 300 hours (36 months), with the exceptions noted below. The maintenance schedule explainer walks through what else falls at those marks, and the torque spec chart has the rest of the fasteners you will touch on the way in.

Three families need a closer look, because the service manual prints the interval more than one way or differs from its neighbors:

  • DF40A/DF50A/DF60A: the procedure page reads "Every 200 hours (12 months)", and the schedule charts for the first serial ranges agree. The chart for serial 310001 and later (2012/09) adds an "Every 300 hrs. or 36 months" column and puts tappet clearance in it; the DF50AV/DF60AV chart (2013/05) does the same.
  • DF200/DF225/DF250: the base procedure reads "Inspect initially after 20 hours (1 month) and every 200 hours (12 months)." The 2006 (K6) chapter says "The maintenance interval of tappet clearance has been changed" and prints "Inspect every 200 hours (12 months)." The chart for serial 540001 and later (2024/06) lists tappet clearance under every 300 hrs. or 36 months. The 2021 DF225/DF250 owner's manual shows valve lash as a dealer item (asterisk) with one inspection mark.
  • DF300, DF250AP/DF300AP: "Inspect every 200 hours (12 months)" on the procedure page, and the DF300 and DF300AP schedule charts both put tappet clearance in the every 200 hrs. column.

Go by the chart that covers your serial number; the manuals judge intervals "by number of hours or months, whichever comes first." The owner's manual charts for the DF115B/DF140B and larger engines run to an every 300 hrs. column as well and show valve lash with a single inspection mark. In the 2023 DF150A/DF175A/DF200A and 2022 DF300B/DF350A owner's manuals that mark sits under every 300 hrs. The text copies we hold of the others do not preserve which column it sits in, so read it off your own manual.

Screw-and-lock-nut vs shim: what each means for you

Screw type (DF2.5, DF4/DF5/DF6, DF8A/DF9.9A, DF9.9B/DF15A/DF20A, DF25A/DF30A)

A threaded adjuster sits in the rocker arm with a lock nut behind it. You hold the adjuster, loosen the nut, turn the adjuster until a feeler gauge of the right thickness drags lightly between the valve stem and the rocker, then tighten the lock nut to the torque in the table while still holding the adjuster, and recheck. No parts are consumed except the head cover gasket. It is a tools-and-patience job, but Suzuki still asterisks it in the owner's manuals we can read, so it is on the dealer-recommended list. The DF8A/DF9.9A, DF9.9B/DF15A/DF20A and DF25A/DF30A manuals list two special tools for it: thickness gauge 09900-20803 and valve adjustment driver 09917-14910, which turns the adjusting screw.

Shim type (DF40A/DF50A/DF60A and every larger family we hold a service manual for)

There is no adjuster. The clearance is set by a hardened shim of a specific thickness between the cam and its follower, so correcting it means measuring the existing clearance, calculating the shim you need from the manual's formula, and swapping it. The DF40A/DF50A/DF60A manual states the formula as "IN. side: A = B + (C – 0.20 mm) EX. side: A = B + (C – 0.30 mm) A: Correct thickness of shim for proper tappet clearance (mm) B: Thickness of original shim (mm) C: Original tappet clearance (mm)", and it adds: "When installing shim, identification mark on the shim should face down (towards tappet)." The DF100A/115A/140A manual uses A = B + (C – 0.25 mm) for both sides. The other six families keep 0.25 mm on the intake side and change the exhaust side: A = B + (C – 0.32 mm) on the DF70A/DF80A/DF90A/DF100B and DF150A/DF175A/DF200A, and A = B + (C – 0.35 mm) on the DF100C/DF115B/DF140B, DF200/DF225/DF250, DF300 and DF250AP/DF300AP, and DF300B/DF325A/DF350A. Measuring is possible with the cover off, but swapping shims is dealer work.

All eight shim-type manuals describe the same layout: a shim disc "fitted to the top of the tappet", measured with thickness gauge 09900-20803 between the cam and the shim surface. To change one, a tappet holder goes on with the camshaft housing bolts and the shim is lifted out with a magnet. The tappet holder numbers as printed:

Two things in these manuals change how you work. First, direction: the DF40A/DF50A/DF60A manual says "Rotate crankshaft clockwise to prevent water pump impeller damage." The seven larger families are left hand (LH) rotation powerheads, and their manuals turn the crankshaft counterclockwise to bring each cam nose vertical to the shim surface; the DF300, DF250AP/DF300AP manual puts it as "Rotate crankshaft counterclockwise to prevent water pump impeller damage." The DF150A/DF175A/DF200A and DF300B/DF325A/DF350A manuals each attach a NOTE to one step of the shim change, marked "This step only": "Rotate the crankshaft clockwise, otherwise the valves may contact with the piston head." Second, hands: every one of them tells you to keep your hand or fingers out from between the camshaft and the tappet when a shim is removed or installed. The DF300B/DF325A/DF350A manual's WARNING reads "Failure to take proper precautions when installing or removing the tappet shim can result in severe personal injury."

All of this is the service manuals' procedure condensed for reference. Suzuki writes it for trained technicians with the special tools; the DF100C/DF115B/DF140B manual, like the other shim-type manuals, carries the line "This service manual is intended for authorized Suzuki outboard motor dealers and qualified service technicians only." If the motor is under warranty, check with your dealer.

The screw-type procedure, as the service manuals print it

This is an overview of the DF2.5 and DF4/5/6 procedure, quoted where the step matters. It is not a substitute for the service manual, which has the drawings that identify the parts.

  1. Engine cold. Remove the motor cover, recoil starter and spark plug, then the four bolts and the cylinder head cover.
  2. Bring the piston to top dead center on the compression stroke. Both manuals print it the same way: "Rotate the flywheel clockwise to bring the piston to the Top Dead Center (TDC) on a compression stroke." Only ever turn it clockwise. The same manuals say "Rotate the crankshaft clockwise to prevent water pump impeller damage."
  3. Confirm you are on the compression stroke, not exhaust, with the rocker test: "If both rocker arms do not move at all, the piston is at the position on a compression stroke. If any rocker arm moves, the piston is at the TDC position on an exhaust stroke. Rotate the flywheel one more turn."
  4. Measure the clearance between the valve stem end and the rocker arm with a feeler gauge and compare it with the chart.
  5. Adjust if it is out. DF4/5/6: "Loosen the valve adjusting lock nut 1 while holding the pivot nut 2. Turn the pivot nut 2 to bring the valve clearance to within the specification." DF2.5: "Tighten the lock nut 1 to the specified torque while holding the adjusting screw 2." Recheck after tightening, because the nut moves the setting.
  6. Refit the head cover with a new gasket (Suzuki's general rule: gaskets, locking nuts and similar parts removed in service are always replaced with new) and "Tighten the four cylinder head cover bolts diagonally to the specified torque."

The DF9.9B/15A/20A and DF25A/30A are the same screw-and-lock-nut design with an 11 N·m lock nut and 10 N·m cover bolts, but they drive the cam with a timing belt (inspected every 200 hours, replaced every 4 years), so use that family's service manual for finding TDC rather than the single-cylinder rocker test above. One warning from the DF9.9B/15A/20A manual applies if you go further than the cover: "Do not rotate the cam pulley and/or crankshaft with timing belt removed." The DF8A/DF9.9A is the same design again, with the same 11 N·m lock nut and 10 N·m cover bolts and a timing belt replaced every 4 years. Its manual finds TDC for each cylinder at the cam pulley: "Align each PUNCH mark on cam pulley with INDEX mark on thermostat cover", punch mark 1 for the No.1 cylinder and 2 for the No.2 cylinder. It turns the flywheel clockwise to get there, under the CAUTION "Rotate the crankshaft in the normal running direction only (clockwise) to prevent water pump impeller damage."

Symptoms of valves out of adjustment

Keep this short because the only real test is a feeler gauge. Clearance that has closed up (too tight) holds the valve slightly off its seat, so compression bleeds off: hard starting, rough idle, and in the long run a burned exhaust valve. The low-compression cause list in every Suzuki service manual we hold includes "Poor seating of valves", which is why a compression test is the right first step when a motor that once ran well starts hard. Clearance that has opened up (too loose) is noisier, a light ticking from the top of the powerhead at idle, and costs a little lift and power. Neither is an emergency, but neither fixes itself, and a tight valve gets worse with hours.

Parts for this job

On the screw-type portables the only consumable is the head cover gasket, in our Suzuki OEM gaskets, seals and O-rings collection. Shims, rocker arms, adjusters and lock nuts for the whole range are in Suzuki OEM valve train and camshafts, and Suzuki's special tools are in Suzuki OEM service tools. If you are doing the 20-hour or 200-hour service at the same time, the model guides cover the rest: DF2.5, DF4A/5A/6A, DF9.9B/15A/20A and DF25A/30A. Orders over $149 ship free to the lower 48.

Sources: Suzuki 4-Stroke Outboard Maintenance Manual (2025.02 edition); Suzuki owner's manuals for DF2.5, DF4A/6A, DF8A/9.9A, DF9.9B/15A/20A, DF25A/30A, DF40A/50A/60A, DF75/90A, DF100A/115A/140A, DF115B/140B, DF115BG/140BG, DF150A/175A/200A, DF150AP/175AP/200AP, DF225/250, DF250AP/300AP and DF300B/350A; Suzuki service manuals 99500-97J01-01E (DF2.5), 99500-91J03-01E (DF4/5/6), 99500-99J00-01E (DF8A/9.9A), 99500-89L00-01E (DF9.9B/15A/20A), 99500-94L10-01E (DF25A/30A), 99500-88L11-01E (DF40A/50A/60A, with the earlier DF60 edition 99500-88L01-01E), 99500-87L10-01E (DF70A/80A/90A/100B), 99500-92J00-01E (DF100A/115A/140A), 99500-99L10-01E (DF100C/115B/140B), 99500-96L30-01E (DF150A/175A/200A, A and AP), 99500-93J05-01E (DF200/225/250), 99500-98J02-01E (DF300, DF250AP/300AP) and 99500-98L10-01E (DF300B/325A/350A). Figures are Suzuki's published values; confirm against the manual for your model year and serial number.