Somewhere in a drawer at your cottage is a receipt for the wrong oil filter. Maybe a forum thread said your 115 takes the same filter as your buddy's. Maybe a parts site matched on horsepower and ignored the serial number. Either way, Mercury builds two different 115s with...
Quick answer: Mercury publishes a factory part number for every maintenance item on every outboard: oil filter, fuel filter, spark plugs, thermostat, impeller, gear lube, anodes, and pre-assembled 100-hour and 300-hour kits. The tables below list them all, from 2.5 to 600 HP, based on Mercury's Quick Reference Guide (Feb 2024 revision). Confirm fitment against your serial number before ordering, because part numbers change at specific serial breaks.
Somewhere in a drawer at your cottage is a receipt for the wrong oil filter.
Maybe a forum thread said your 115 takes the same filter as your buddy's. Maybe a parts site matched on horsepower and ignored the serial number. Either way, Mercury builds two different 115s with two different filters, and horsepower alone won't tell you which one is on your transom.
Mercury actually publishes all of this in a dealer chart most owners never see. This guide is that chart, written out in plain language: every filter, plug, kit, impeller, and lube spec, organized by motor family and serial range. Bookmark it, check it against your serial number, and you'll never guess at a part again.
Who this is for
Owners of any modern Mercury four-stroke outboard from 2.5 to 600 HP who want the exact factory part numbers for routine maintenance. That covers DIYers doing their own oil changes, buyers pricing out a 100-hour service, and anyone tired of cross-referencing three parts sites that disagree with each other. If you run a two-stroke or a pre-2000s motor, these tables won't cover you; the numbers below apply to the current four-stroke families in Mercury's Feb 2024 reference guide.
Serial Number First, Horsepower Second
Before you touch the tables, find your serial number. It's on a plate on the transom bracket, and it decides everything.
Mercury has built multiple generations of the same horsepower. A 15 HP before serial 0R833820 is a carbureted motor that takes 10W-30. From that serial on, it's an EFI motor that takes 25W-40. Same badge on the cowl, different oil, different filter, different kit.
The big serial breaks to know:
- 15/20 HP: carb vs EFI at serial 0R833820
- 75-115 HP: 1.7L block (1B366823-2B094995) vs 2.1L block (2B095049 and up)
- Verado 200-300 I6: maintenance kits change at serial 2B144123
- V6 and V8 (175-300 HP): current parts apply from serial 2B529482 up
If you're not sure how to decode yours, our serial number guide walks through it.
2.5 to 30 HP: Portables and Tillers
The small motors are simple. Most have no oil filter at all (you just drain and refill), and the maintenance kits are 300-hour only.
| Part |
2.5/3.5 |
4/5/6 |
8/9.9 |
15/20 (carb, to s/n 0R833819) |
15/20 (EFI, s/n 0R833820+) |
25/30 EFI |
| Engine oil |
10W-30, 0.3 L (10 oz) |
10W-30, 0.44 L (15 oz) |
10W-30, 0.8 L (27 oz) |
10W-30, 1.0 L (34 oz) |
25W-40, 1.0 L (1.1 qt) |
10W-30, 1.8 L (1.9 qt) |
| Oil filter |
None |
None |
None |
8M0162831 |
8M0162831 |
8M0162831 |
| Fuel filter |
None |
8M0157133 |
8M0157133 |
8M0157133 |
8M0134466 |
8M0088825 |
| Spark plug |
8M0204682 |
8M0204682 |
8M0204682 |
8M0204682 |
8M0204682 |
8M0204682 |
| Thermostat |
804540 |
804540 |
8M0119207 |
8M0119207 |
8M0139434 |
8M0119207 |
| Gear lube |
Premium, 180 mL (6.1 oz) |
Premium, 190 mL (6.5 oz) |
Premium, 320 mL (10.8 oz) |
Premium, 370 mL (12.5 oz) |
Premium, 460 mL (15.6 oz) |
Premium, 350 mL (11.8 oz) |
| Impeller / kit |
161543 / 889246A16 |
161543 / 8M0155395 |
8M0214945 / 803748K01 |
8M0214944 / 8M0122064 |
8M0135803 / 8M0135821 |
8M0214912 / 8M0208905 |
| 300-hr kit |
None |
8M0120836 |
8M0120837 (std) / 8M0120867 (Command Thrust) |
8M0120838 |
8M0151470 (100-hr: 8M0151469) |
8M0120839 |
Oil part numbers: 10W-30 is 8M0142141 per quart; 25W-40 is 8M0078629. That holds across every table on this page.
40 to 60 HP: The Cottage Workhorses
Two versions here, and the gearcase is the difference. Command Thrust runs a bigger gearcase with more than double the lube capacity, a different impeller, and different kits. Check your model code before ordering. Our Command Thrust guide explains what the gearcase actually does.
| Part |
40/50/60 Command Thrust |
40/50/60 Standard Gearcase |
| Engine oil |
25W-40, 2.8 L (3.0 qt) |
25W-40, 2.8 L (3.0 qt) |
| Oil filter |
8M0162829 |
8M0162829 |
| Oil change kit |
8M0081916 |
8M0081916 |
| Fuel filter |
879884T |
879884T |
| Spark plug |
883323001 |
883323001 |
| Thermostat |
8M0168892 |
8M0168892 |
| Gear lube |
High Performance, 710 mL (24 oz) |
Premium, 340 mL (11.5 oz) |
| Impeller / kit |
43026T2 / 8M0100527 |
19453T / 812966A12 |
| 100-hr kit |
8M0090558 |
8M0090558 |
| 300-hr kit |
8M0090559 |
8M0113483 |
75 to 150 HP: Where the Serial Number Really Matters
The 75-115 range is the most commonly mis-ordered family we see. Two blocks, two oils, two filter part numbers, and nothing on the cowl tells you which you have. Serial number or nothing.
| Part |
75/90/115 1.7L (s/n 1B366823-2B094995) |
75/90/115 2.1L (s/n 2B095049+) |
150 FourStroke (s/n 1B905505+) |
| Engine oil |
25W-40, 4.9 L (5.2 qt) |
10W-30, 5.2 L (5.5 qt) |
10W-30, 6.0 L (6.3 qt) |
| Oil filter |
877761K01 |
8M0162829 |
877761K01 |
| Oil change kit |
8M0081917 |
8M0107510 |
8M0188357 |
| Fuel filter |
879885K |
879885K |
879885K |
| Spark plug |
8M0157328 |
8M0204728 |
8M0204728 |
| Thermostat |
8M0090819 |
8M0090819 |
8M0090819 |
| Drive belt |
897574Q01 |
None |
8M0031641 |
| Gear lube |
High Performance, 710 mL (24 oz) |
High Performance, 800 mL (27.1 oz) std gearcase |
High Performance, 830 mL (28.1 oz) |
| Impeller / kit |
43026T2 / 8M0100527 |
43026T2 / 8M0100527 |
43026T2 / 8M0094529 |
| 100-hr kit |
8M0097856 |
8M0097854 |
8M0094232 |
| 300-hr kit |
8M0097857 |
8M0097855 |
8M0094233 |
The 2.1L block covers the current 75, 90, and 115, including the 115 Pro XS. The 1.7L is the earlier generation, and it takes different oil, a different filter, and a different plug. This is the table to screenshot.
175 to 300 HP: V6 and V8 FourStroke and Pro XS
Current-generation V6 (3.4L) and V8 (4.6L) motors, serial 2B529482 and up. These share most consumables, with a kit split on the V8 depending on gearcase.
| Part |
175-225 V6 (3.4L) |
225-300 V8 (4.6L) |
| Engine oil |
10W-30, 6.6 L (7.0 qt) |
10W-30, 6.6 L (7.0 qt); SeaPro versions run 25W-40 |
| Oil filter |
8M0123025 |
8M0123025 |
| Oil change kit |
8M0187621 |
8M0187621 |
| Fuel filter |
8M0106635 |
8M0106635 |
| Spark plug |
8M0204737 |
8M0204737 |
| Thermostat |
8M0162139 |
8M0162139 |
| Drive belt |
8M0142251 |
8M0142251 |
| Gear lube |
High Performance, 710 mL (24 oz); 5.44 gearcase 720 mL (24.4 oz) |
High Performance, 710 mL (24 oz); 5.44 gearcase 720 mL (24.4 oz) |
| Impeller / kit |
43026T2 / 8M0205802 |
43026T2 / 8M0205802 |
| 100-hr kit |
8M0149929 |
8M0149929 |
| 300-hr kit |
8M0149930 |
8M0149931 (std gearcase) / 8M0149932 (Verado and SeaPro gearcase) |
| MerCathode kit |
88334A2 |
88334A2 |
Verado: 150 to 600 HP
Verado spans four very different machines, from the older four-cylinder to the V12 with its own service logic (200-hour and 1,000-hour intervals instead of 100/300). The I6 has a kit split at serial 2B144123, which catches people constantly.
| Part |
150/175/200 4-cyl (s/n 1B517159-2B576734) |
200-300 I6 (s/n 2B144123-2B578935) |
350-400 6-cyl (s/n 2B141124+) |
350-400 V10 (5.7L, s/n 3B266064+) |
600 V12 (7.6L, s/n 3B060061+) |
| Engine oil |
25W-40, 6.0 L (6.3 qt) |
25W-40, 7.0 L (7.4 qt) |
25W-40, 7.0 L (7.4 qt) |
25W-40, 9.5 L (10 qt) |
10W-30, 13.2 L (14 qt), PN 8M0173224 |
| Oil filter |
877767K01 |
877769K01 |
877769K01 |
8M0205848 |
8M0168366 |
| Oil change kit |
8M0188358 |
8M0188359 |
8M0188359 |
None listed |
None listed |
| Fuel filter |
8M0122424 (red castle nut) |
8M0122424 (red castle nut) |
8M0122424 (red castle nut) |
8M0157616 |
8M0166596 |
| Spark plug |
889246Q39 |
889246Q39 |
889246Q39 |
8M0204737 |
8M0180173 |
| Thermostat |
8M0174561 |
8M0174561 |
8M0174561 |
Upper 8M0205186 / Lower 8M0205215 |
8M0177662 |
| Drive belt |
880566Q14 |
880566Q14 |
880566Q14 |
8M0178243 |
8M0178243 |
| Gear lube |
High Performance, 970 mL (32.8 oz) |
High Performance, 970 mL (32.8 oz); 5.44 HD 510 mL (17.2 oz) |
High Performance, 970 mL (32.8 oz); 5.44 HD 510 mL (17.2 oz) |
High Performance, 1.4 L (1.5 qt) |
High Performance, 2.8 L (3 qt) |
| Impeller / kit |
443026T2 / 8M0100527 |
443026T2 / 8M0100527 |
443026T2 / 8M0100527 |
8M0200115 / 8M0200136 |
8M0177706 / 8M0177997 |
| 100-hr kit |
None (300-hr only) |
8M0120657 (s/n 2B144122 and below: 8M0097858) |
8M0120657 |
8M0207807 |
200-hr: 8M0179987 |
| 300-hr kit |
8M0130835 |
8M0133617 (s/n 2B144122 and below: 8M0097859) |
8M0133617 |
8M0207808 |
1000-hr: 8M0179988 |
| MerCathode kit |
88334A2 |
88334A2 |
88334A2 |
8M0180081 |
8M0180081 |
100-Hour Kits vs 300-Hour Kits: Which One You Actually Need
Mercury's maintenance kits bundle the parts for the scheduled service in one box, at less than the parts cost individually in most cases.
The 100-hour kit covers the annual service: oil filter, fuel filter, gaskets, and drain plug seals. If you boat a normal Rice Lake season (50-100 hours a year), this is your every-year kit.
The 300-hour kit adds the bigger-interval items: water pump components, thermostat pieces, and on belt-driven motors, the belt. Think of it as the 100-hour kit plus the wear parts that live on a three-year clock.
The rhythm is simple: 100-hour kit annually, 300-hour kit every third year. Our maintenance intervals guide breaks down what gets done at each stage and why the hour counter isn't the only trigger. Water pump impellers in particular age out before they wear out; we covered what actually happens to them in our impeller replacement post.
Oil and Gear Lube: The Spec Details People Get Wrong
Engine oil. Mercury four-strokes run either 10W-30 or 25W-40 depending on model, and both must carry the FC-W marine four-stroke rating. TC-W3 is two-stroke oil. It's not a "marine oil" catch-all, and it does not go in your four-stroke. Capacities are in the tables above; for a deeper dive on fill volumes, see our oil capacity chart.
Gear lube comes in two grades, and they're not interchangeable spec-for-spec:
- Premium Gear Lube (802844K02 / 858058K01): small motors and standard gearcases up to 60 HP
- High Performance Gear Lube (858064K01): Command Thrust gearcases and everything from 75 HP up
If your gear lube comes out looking like coffee with cream, stop and read our milky gearcase oil post before you just top it up. That colour means water, and water means a seal problem.
Anodes: Aluminum for Rice Lake
Anodes are the one item on Mercury's chart where the answer depends on your water, not just your motor.
- Aluminum anodes work in fresh, brackish, and salt water. They're the right call for Rice Lake and the Kawarthas.
- Magnesium anodes are freshwater-only and more active. Fine here, wrong the moment the boat sees salt.
Mid-range motors (40-115 HP) use anode kit 8M0107547. Larger families split by gearcase and trim configuration, and the anode list gets long enough that we'd rather confirm against your serial number than have you order three wrong ones. The rule that matters: replace anodes when they're half gone, and never paint them.
What we see at HBW
The parts counter tells the same story every spring. Someone winterized their own 115 last fall, ordered the filter their forum thread recommended, and it was the 1.7L filter for a 2.1L motor. Or a Verado owner grabbed the pre-2B144123 kit for a post-break motor and ended up with two returns and a lost weekend.
Out of 584 winterizations and 507 paid service jobs last season, the pattern is consistent: the motors that hit trouble are rarely the ones that missed a spec. They're the ones where the right part got guessed at instead of looked up. Serial number first. Every time. That habit is most of what separates a 20-year motor from a 10-year one.
Common mistakes
- Ordering by horsepower alone. The 75-115 family and the Verado I6 both changed parts mid-run. The serial break decides, not the badge.
- Automotive filters and oil. Car filters lack the anti-drainback and burst specs for marine duty, and car oil isn't FC-W rated. The few dollars saved aren't worth a warranty argument.
- Mixing gear lube grades. Premium in a Command Thrust or V8 gearcase is the wrong spec for the load those gears carry.
- Skipping the 300-hour items because "it runs fine." Impellers and thermostats fail by age and heat cycles, not just hours. Running fine is what every motor does right up until it doesn't.
- Buying anodes for the wrong water. Magnesium anodes in salt water erode fast. Aluminum covers you everywhere, including here.
Ready to Order Parts or Book the Service?
If you know what you need, look it up and order through our Mercury parts lookup. If you'd rather have the whole 100-hour or 300-hour service done right in one visit, put in a service request and we'll take it from there.
Parts: harrisboatworks.ca/mercuryparts
Service: hbw.wiki/service
Phone: 905-342-2153
Sources
- Mercury Marine Quick Reference Guide: Maintenance Products for Mercury Outboards, MER-5746, Feb 2024 revision (part numbers, capacities, serial ranges)
- Mercury Marine owner's manuals (service intervals, oil specifications)
- Metric conversions: 1 US qt = 0.946 L, 1 US fl oz = 29.57 mL, rounded to the nearest 0.1 L / 5 mL
Phone: 905-342-2153
Address: 5369 Harris Boat Works Rd, Gores Landing, ON
Configurator: mercuryrepower.ca
