8M0118177 Mechanical Fuel Pump Assembly

Mechanical Fuel Pump — Compatible with select Mercury Mariner 30–60 HP Four-Stroke EFI

Which pump is this?

This is one complete mechanical lift pump for Mercury / Mariner four-stroke EFI engines in the 30–60 HP class. Current ordering numbers are 8M0118177 and 8M0141827. Predecessors: 881862T, 881862T08, 892874T01, 899106T01. Compatible with the EFI rows in the table: 30 HP EFI 3-cyl, 35 HP EFI jet, 40 HP EFI 3-cyl and 4-cyl (including jet and SeaPro), 50 HP EFI 4-cyl, 60 HP EFI 4-cyl / SeaPro / 1.0L APX / 60R / Formula 60. It is not the carb 25 / 30 / 40 HP 3-cyl family (8M0141844 / 881862T1 / T07 — that is 21FP004). Aftermarket pages that mix carb and EFI under one number are too wide. 25 HP four-stroke carb is not on this page.

Signs yours is due

• 30–60 HP four-stroke EFI cranks, fires, then dies or will not build rail pressure after a hot soak — the mechanical lift pump ahead of the EFI system is tired.
• Fuel weep at the block pump on an EFI motor (throttle body / injectors, not carb bowls).
• Old stamp is 881862T08 or 899106T01, not 881862T07 / 8M0141844.
• Not a VST high-pressure electric module failure alone, and not a cooling impeller.

Will it fit?

Compatible with Mercury / Mariner EFI serial bands in the table — organized by serial, not model year. Examples: 30 HP EFI 0P153500–0P400999, 0T409000–1B226999, and later 1C109093 & up; 40 / 50 / 60 HP EFI 4-cyl share long 0P / 0T / 1B / 1C lists; 35 jet / 40 SeaPro / 60 SeaPro 1C453840 & up; 60 HP 1.0L APX 1C782688 & up; 60R 1C615064 & up; Formula 60 1C104574–1C782687. Read EFI vs carb on the cowl and the serial on the midsection. Some parts lists also print 8M0141827 on later 40 HP carb — that carb application is 21FP004, not a reason to mix the two pages.

Engine horsepower alone does not prove fit. Match the number stamped on the pump you remove to the OEM column.

Every row is from this SKU fitment workbook (12 rows after empty-line filter). Same horsepower name shipped different pumps.

OEM and swap numbers

OEM / predecessor numbers keep the engine-brand column. Aftermarket cross-refs are numbers only.

Wrong part

• NOT 8M0141844 / 881862T1 / 881862T07 — carb 25 / 30 / 40 HP 3-cyl (21FP004).
• NOT diaphragm kit 883520A1 (rebuild kit, not the complete pump).
• NOT high/low dual-pump assemblies 1399-39540 / 883202T02.
• NOT 2-stroke 14360A16 / A78.

What ships

One complete mechanical fuel-pump assembly. No EFI high-pressure module, no filter, no carburetor.

Often replaced together

Carb 25 / 30 / 40 HP 3-cyl is 21FP004. Pump-plus-filter kit is 26FFK032. Diaphragm-only kit 883520A1 is not this page.

Install

Confirm the motor is EFI, not carb, before you open the cowl. Read the serial against the table. Photograph the pulse hose. This pump is the mechanical lift pump on the block, not the high-pressure electric unit. Clean the pad, align the pulse hole, snug screws evenly. Prime, leak-check, idle on muffs. If the stamp is 881862T07 or 8M0141844, you want 21FP004.

Frequently Asked Questions

Will this fit my Mercury 40 HP four-stroke?

Only EFI 40 HP rows in the table. 40 HP carb 3-cyl uses 8M0141844 (21FP004). Read EFI vs carb and the serial.

Is 18-8866 this pump?

18-8866 is a cross-ref number for this EFI family. We list the number only. It is not the carb 25–40 HP pump.

T08 vs T07?

881862T08 is EFI (this page). 881862T07 is carb (21FP004). One suffix off is a different pump.

Does it fit 25 HP?

No 25 HP EFI row is on this table. 25 HP carb is 21FP004.

What ships?

One mechanical lift pump. Not the 26FFK032 kit.

Please note

Aftermarket fuel pump by GHMarine. Not affiliated with the engine brands named above. «Compatible with», «Replaces», and cross-ref numbers mean this part is built to work like the originals listed — always confirm the stamp on the removed pump, the engine model, and the serial range before you order. This page is the pump only, not a multi-part kit.