Suzuki Cylinder Head Assembly Part Numbers by Model, and How to Tell a Complete Head from a Bare One

A complete Suzuki cylinder head is one of the part numbers on Suzuki's assembly bulletin PA23-13 (June 2023), or a number in the same supersession chain. In our catalog those are the listings named Cylinder Head Set or Cylinder Head Assembly. A cylinder head under any other part number is the bare part: it ships empty, with no internal parts.

The tables below list every cylinder head on that bulletin by model, with a link where we carry the number. The bulletin prints the part number, the model and the production years. It does not print a contents list, so we do not publish one here. Send us the model code and serial number from the motor's ID plate and we will confirm the part number that fits before you order.

How to tell a complete head from a bare one in our catalog

The listing name and the start of the part number tell you which one you have found.

V6 heads are side-specific. On Suzuki V6 outboards the starboard and port cylinder head sets are separate part numbers, so order by side.

Cylinder head part numbers on Suzuki bulletin PA23-13

Suzuki Marine USA parts bulletin PA23-13 is dated June 16, 2023 and gives what it calls the latest part numbers, current as of June 2023, for lower units, cylinder heads and short engines. The other two lists are on our complete lower unit part numbers and short engine assembly part numbers pages. The bulletin splits cylinder heads into later and earlier models, and the tables keep that split.

• Model is as the bulletin prints it. STBD is the starboard head and PORT the port head.
• Production years are the bulletin's from and to years; "2010 and later" is its own wording. No row names a year after 2022, so ask us about a newer motor.
• Bulletin note is Suzuki's remark. The DF40 and DF60 heads are marked "Discontinued 2022" and the DF90 head "Discontinued 2023"; ask us before you plan a repair around one.
• In our store says whether we list that exact number; where we do, the part number links to the listing. "Not listed under this number" does not mean the head cannot be had: Suzuki has superseded numbers since June 2023, so send us the model code and serial number.

Check the year as well as the model. The DF70A is 11010-87LV0 in the earlier-model list, from 2009, and 11010-87LV2 in the later-model list, for 2020 to 2021.

The bulletin's head list starts at the DF25 V-Twin and the DF25A/30A. It has no row for the DF2.5, DF4/DF5/DF6, DF8A/9.9A or DF9.9B/15A/20A. For those, send us the model code and serial number, and treat any listing as bare unless it is named Cylinder Head Set or Cylinder Head Assembly.

Later models

This is the bulletin's "Later Model" list, from the DF25A/30A up to the DF350A.

Earlier models

This is the bulletin's "Earlier Model" list, from the DF25 V-Twin up to the DF300.

Other cylinder head sets in our catalog

We also list cylinder head sets under numbers that are not on the June 2023 bulletin. They are listed as Cylinder Head Set or Cylinder Head Assembly, not as bare heads, and where our listing states a supersession it is shown. We make no fitment claim for them here. Send us the model code and serial number and we will match one to your motor.

• 11010-87LV3
• 12000-88815
• 12000-93Y32 (our catalog shows it superseded by 12000-93Y33)
• 12000-93Y36
• 12000-93Y37
• 12000-93Y46
• 12000-93Y47
• 12000-93Y53 (our catalog shows it superseded by 12000-93Y54)
• 12000-93Y57
• 12000-93Y61 (our catalog shows it superseded by 12000-93Y62)
• 12000-93Y62 (our catalog shows it superseded by 12000-93Y63)
• 12000-93Y67
• 12000-93Y77
• 12000-93Y84 (our catalog shows it superseded by 12000-93Y85)
• 12000-93Y87
• 12000-93Y93
• 12000-93Y94
• 12000-96845 (our catalog shows it superseded by 12000-96846)
• 12000-96888
• 12000-96Y16
• 12000-96Y26
• 12000-96Y30
• 12000-98843 (our catalog shows it superseded by 12000-98845)
• 12000-98867
• 12000-98Y14
• 12000-98Y24
• 12000-98Y33
• 12000-99844

Is the old head reusable? What the service manuals measure

A new head only fixes a fault that is in the head. Suzuki's service manuals list five causes of low compression. Two are at the head: poor seating of valves, and a ruptured or otherwise damaged cylinder head gasket. The other three (excessively worn cylinder wall, worn piston or piston rings, stuck piston rings) are in the block. Run a compression test first; if the block is the problem, see the short engine page linked above.

The casting itself

• Cracks. The manuals check the intake and exhaust ports, the combustion chambers, the head surface and the valve seats. The DF9.9B/15A/20A manual says to replace the cylinder head if cracks or other damage is found.
• Gasket-surface distortion. It is measured with a straightedge and a thickness gauge at six locations. Over the limit, resurface or replace the head. A distorted mating surface, the manual says, lets combustion gas and/or cooling water leak, which may result in overheating and reduced power.
• Resurfacing. The DF2.5, DF4/DF5/DF6 and DF9.9B/15A/20A manuals describe a surface plate and #400 grit wet sandpaper, moving the head in a figure eight pattern. How much material may come off is not stated in the DF9.9B/15A/20A manual we have.

The DF200/DF225/DF250 row also covers the DF250S. On that family, the DF300 family and the DF300B/DF325A/DF350A, each bank has its own cylinder head. In the DF300, DF250AP/DF300AP manual the inspection procedure is printed only for the 2007 DF300 (DF300T/DF300Z), but the service data tables in the DF300AP, DF250AP/DF300AP, DF250ATSS and DF250AUN supplements print the same two limits.

Valves, guides, seats and springs

These printed figures decide whether the valves, guides and springs go back in.

The DF300, DF250AP/DF300AP row quotes the 2007 DF300 (DF300T/DF300Z) inspection procedure. The service data tables in the DF300AP, DF250AP/DF300AP, DF250ATSS and DF250AUN supplements print the same limits, with the seat contact width as 1.1–1.3 mm (0.04–0.05 in) and the spring limit as 38.2 mm (1.50 in).

On the DF2.5 a worn guide can condemn the head by itself: over the limit, the manual says to replace the valve and/or the cylinder head. On the DF4/DF5/DF6 the same reading means replacing the valve and/or the valve guide, and a removed guide is never reused.

On the DF4/DF5/DF6, from serial number 110001 the spark plug hole thread in the head changed from 14 mm to 10 mm. The manual says the new cylinder head can be installed on an early model with the new cylinder head, spark plug and spark plug cap used together as a set.

Camshaft and tappet bores

The camshaft runs in the head, so its checks can end a head's life too.

• Rocker-arm engines (DF8A/DF9.9A, DF9.9B/DF15A/DF20A, DF25A/DF30A): camshaft journal oil clearance service limit 0.100 mm (0.0039 in.). Over it, replace the camshaft and, if necessary, the cylinder head and/or the oil gallery block; the DF8A/DF9.9A manual names the oil pump in place of the oil gallery block. These engines work their valves through rocker arms, not tappets, so there is no tappet bore figure. All three manuals print a rocker arm shaft to rocker arm clearance limit instead: 0.060 mm (0.0024 in.).
• Tappet engines, from the DF40A/DF50A/DF60A to the DF300B/DF325A/DF350A: every manual prints the same two limits. Camshaft journal oil clearance service limit 0.120 mm (0.0047 in.); cylinder head bore to tappet clearance service limit 0.150 mm (0.0059 in.). That covers the DF40A/DF50A/DF60A, DF70A/DF80A/DF90A/DF100B, DF100A/DF115A/DF140A, DF100C/DF115B/DF140B, DF150A/DF175A/DF200A, DF200/DF225/DF250 with the DF250S, the DF300 and the DF300B/DF325A/DF350A.
• Over those limits: the DF40A/DF50A/DF60A and DF100A/DF115A/DF140A manuals say to replace the tappet or the cylinder head when tappet clearance is over the limit. Over the journal limit, the DF100C/DF115B/DF140B and DF300B/DF325A/DF350A manuals have you replace the camshaft and/or the cylinder head, based on the measurements.
• Camshafts differ by model on several engines: the DF70A/DF80A/DF90A/DF100B manual says the DF70A, DF80A and DF90A/100B camshafts differ and prints an identification mark for each; the DF200/DF225/DF250 manual says the DF200, DF225 and DF250 camshafts differ from each other, and it prints a camshaft runout service limit of 0.10 mm (0.004 in.). On the DF300B/DF325A/DF350A the exhaust camshaft is different between the DF325A and DF350A.

For the DF300, DF250AP/DF300AP family the measuring procedure is printed only for the 2007 DF300 (DF300T/DF300Z); the service data tables in the DF300AP, DF250AP/DF300AP, DF250ATSS and DF250AUN supplements print the same two limits.

Every one of the tappet-engine manuals adds that the camshaft housing and cylinder head must be replaced as a set. That is a service instruction, not a statement of what ships under a head part number, so confirm with us before you order. A cam lobe worn past its height limit means a new camshaft, not a new head; see valve train and camshafts.

What replacing a head involves

This is dealer or experienced-shop work. On both engines below, the power unit comes off the motor before the head does, and the cam drive has to be removed and timed again. Suzuki's DF9.9B/15A/20A service manual says it is intended for authorized Suzuki outboard motor dealers and qualified service technicians only. If the motor is under warranty, check with your dealer first.

DF70A, DF80A, DF90A and DF100B

1. Remove the power unit, then the oil pump and the timing chain. Do not rotate the camshaft or crankshaft with the timing chain removed.
2. Remove the bolts securing the camshaft housings, then the intake and exhaust camshafts, then the tappets and tappet shims. All of them must be installed in their original positions.
3. Loosen and remove the fifteen cylinder head bolts in the order shown in the manual's figure, with the 10 mm deep socket wrench (09919-16010). Lift off the head and gasket.
4. Fit the dowel pins and a new head gasket. The manual's words: "Always use a new gasket."
5. Apply engine oil to the head bolts and tighten in four stages:
   • all bolts to 50 percent of specified torque: 35 N·m (3.5 kgf-m, 25.5 lbf-ft) on the 10 mm bolts, 12 N·m on the 8 mm bolts;
   • loosen all bolts to 0, in the reverse sequence;
   • again to 50 percent: 35 N·m (3.5 kgf-m, 25.5 lbf-ft) and 12 N·m (1.2 kgf-m, 8.5 lbf-ft);
   • finally to specified torque: 70 N·m (7.0 kgf-m, 51.0 lbf-ft) and 23 N·m (2.3 kgf-m, 16.5 lbf-ft).
6. Install the camshafts; the camshaft housing bolts go to 11 N·m (1.1 kgf-m, 8.0 lbf-ft) in three passes (1/3, 2/3, then full torque). Install the timing chain and turn the crankshaft two complete turns in its normal running direction to check the match marks. Then adjust tappet clearance and install the oil pump.

DF9.9B, DF15A and DF20A

1. Remove the power unit and the camshaft. Loosen the valve adjusting screws first, to prevent valve damage, and do not turn the cam pulley or crankshaft independently with the timing belt removed.
2. The camshaft comes out after the camshaft pulley, oil pump, rocker arm shaft, spring and rocker arms, pulled toward the oil pan side. Each rocker arm goes back in its original position.
3. Loosen and remove the eight cylinder head bolts in the order shown in the figure, with the 8 mm deep socket wrench (09919-19910).
4. Always use a new head gasket. First apply SUZUKI Bond 1207B sealant to the hatched areas in the manual's illustration, carefully, to avoid overflow.
5. Apply engine oil to the inside head bolts only, not the outside bolts.
6. Lightly seat all the bolts, then follow the order in the figure: 1/2 of specified torque, 15 N·m (1.5 kgf-m, 11 lbf-ft), then full torque, 30 N·m (3.0 kgf-m, 21.7 lbf-ft).
7. Install the camshaft with a new oil seal, the rocker arms, oil pump, power unit and camshaft pulley; the pulley bolt gets thread lock and 10 N·m (1.0 kgf-m, 7.2 lbf-ft). Install the timing belt, check valve clearance before installing the cylinder head cover, and fit a new cover gasket.

The tightening order is not in this article. On both engines it is shown only as numbers on the manual's figure. Work from the manual.

Cylinder head bolts for every engine

The table gives each service manual's bolt count and tightening stages. Read a row left to right: each arrow is the next stage, and a 0 means every bolt is loosened back to zero before the next one.

For every engine in the table the tightening order is shown only in the manual's figure, so work from the manual. On every row that has a 0 stage, the manual says to loosen in the reverse sequence. The DF150A/DF175A/DF200A, DF200/DF225/DF250, DF300 and DF300B/DF325A/DF350A manuals each warn you not to forget the bolts their figures show. Three manuals print a different final figure for the 8 mm bolt in their fastener tables: 27 N·m in the DF200/DF225/DF250 base table (25 N·m in its DF250S and DF200TL tables) and 25 N·m in the DF300 and DF300B/DF325A/DF350A tables. Their procedures all say 23 N·m, which is what the table above gives; check the manual for your model.

Three rows need a note. The DF4/DF5/DF6 row is the base DF4/DF5 manual; the DF6 supplement prints two steps, 14 N·m then 28 N·m. On the DF8A/DF9.9A the bolts come in two lengths, and the shorter ones go in the holes the manual marks A and B. The DF300, DF250AP/DF300AP row is printed only for the 2007 DF300 (DF300T/DF300Z), the only cylinder head procedure in that manual.

The DF300B/DF325A/DF350A row ends with an angle: lightly seat all the bolts, tighten in sequence to 50 N·m (5.0 kgf-m, 36.0 lbf-ft) on the 12 mm bolts and 12 N·m (1.2 kgf-m, 8.5 lbf-ft) on the 8 mm bolts, loosen them all to 0, tighten again to 30 N·m (3.0 kgf-m, 22.0 lbf-ft) and 12 N·m, then bring the inside bolts to 58 N·m (5.8 kgf-m, 42.0 lbf-ft) and turn them a further 90 degrees with an angular torque gauge, and finish the outside bolts at 23 N·m (2.3 kgf-m, 16.5 lbf-ft).

Always use a new head gasket. Every manual says so, and the DF9.9B/DF15A/DF20A, DF25A/DF30A, DF70A/DF80A/DF90A/DF100B, DF100A/DF115A/DF140A, DF100C/DF115B/DF140B, DF150A/DF175A/DF200A and DF300B/DF325A/DF350A manuals give the reason: a previously used gasket may leak combustion gas and/or cooling water. Every manual also has you apply engine oil to the head bolts before tightening; on the DF9.9B/DF15A/DF20A that is the inside bolts only. The DF2.5, DF40A/DF50A/DF60A, DF100A/DF115A/DF140A, DF100C/DF115B/DF140B, DF200/DF225/DF250, DF300 and DF300B/DF325A/DF350A manuals also have you apply sealant to both surfaces of the hatched areas they illustrate before the gasket goes on; where a manual names it, that is SUZUKI Bond 1207B (99000-31140), the sealant in the DF9.9B/DF15A/DF20A steps above. Other fastener torques are in our torque spec chart.

Parts the manuals say to replace

The DF70A/80A/90A/100B and DF9.9B/15A/20A manuals both call for a new cylinder head gasket, a new cylinder head cover gasket and a new intake manifold gasket, and say valve stem seals and valve guides are not reused once removed. The DF9.9B/15A/20A manual adds the camshaft oil seal. Neither tells you to fit new head bolts; both say a replacement fastener must have the same part number or, if that is not available, be the same size with equal or higher strength. Bolts are under engine bolts and fasteners.

What to check after the head is back on

Two checks follow a head job: valve clearance, measured with the engine cold, and compression. The table gives each service manual's figures. The valve clearance chart and the compression test guide cover each check in more detail.

The manuals note that these compression figures are guidelines only, not absolute service limits. The DF2.5 and DF4/DF5/DF6 manuals have you adjust valve clearance after the head goes back on. On the tappet engines the manuals call the valve clearance check tappet clearance.

• DF8A/DF9.9A: the piston must be at TDC on its compression stroke to check or adjust valve clearance.
• DF25A/DF30A: the decompression system affects the reading. Cranked with the starter motor it will usually be 1,500–1,800 kPa; with insufficient engine warm-up or a low capacity battery it will match the recoil starter figure.
• DF100C/DF115B/DF140B: the table gives the procedure's figures. The service data table prints 18.3 kgf/cm² at the top of the range and 14 psi for the maximum difference.
• DF200/DF225/DF250: the DF250W is listed at the same 1,100–1,700 kPa.
• DF300, DF250AP/DF300AP: the 1,100–1,500 kPa standard is printed for the DF300T/DF300Z only, in the 2007 base manual and the later DF300 service data. The DF300AP, DF250AP, DF250ATSS and DF250AUN service data print 880–1,500 kPa. Every one of those tables prints the same 100 kPa maximum difference and the same valve clearance.
• DF300B/DF325A/DF350A: both compression lines are exactly as the manual prints them.

Parts for this job

The complete heads are in the tables above; send us the model code and serial number before you order. If the old head passes inspection, the parts to refit it are in gaskets, seals and O-rings and valve train and camshafts, with the rest under engine and powerhead parts.

Sources: Suzuki Marine USA parts bulletin PA23-13 (June 16, 2023); Suzuki service manuals 99500-97J01-01E (DF2.5), 99500-91J03-01E (DF4/DF5/DF6), 99500-99J00-01E (DF8A/DF9.9A), 99500-89L00-01E (DF9.9B/DF15A/DF20A), 99500-94L10-01E (DF25A/DF30A), 99500-88L11-01E (DF40A/DF50A/DF60A), 99500-87L10-01E (DF70A/DF80A/DF90A/DF100B), 99500-92J00-01E (DF100A/DF115A/DF140A), 99500-99L10-01E (DF100C/DF115B/DF140B), 99500-96L30-01E (DF150A/DF175A/DF200A), 99500-93J05-01E (DF200/DF225/DF250), 99500-98J02-01E (DF300, DF250AP/DF300AP) and 99500-98L10-01E (DF300B/DF325A/DF350A), with their bound-in supplements; Boat Max Online catalog, October 2026. Figures are Suzuki's published values; confirm against the manual for your model year and serial number.