Mercury 250XB (3.0L EFI) (0G980600 THRU 0T800999) Parts & Diagrams

🔎 Mercury 250XB (3.0L EFI) Reference Library — Exploded parts diagrams (31 diagrams), specifications, common issues, and maintenance checklist.

The Mercury 250XB (3.0L EFI) is a 4-Stroke, V8 64-degree, DOHC, 32-valve outboard motor. Designed for large center-consoles, offshore sport-fishing boats, and multi-engine configurations.

Quick Reference Specifications

Specification	Value
Engine Type	4-Stroke, V8 64-degree, DOHC, 32-valve
Horsepower	250 HP
Displacement	4600 cc (4.6L / 279 CID)
Bore x Stroke	92 mm x 86 mm (3.62 in. x 3.38 in.)
Spark Plug (Type & Gap)	NGK LKAR7C-9
Engine Oil Capacity	7.0 L (7.4 qt)
Recommended Engine Oil	Mercury FourStroke Oil 25W-40 (NMMA FC-W SAE 10W-30)
Gear Case Oil Capacity	802 mL (27.1 oz)
Idle Speed (in gear)	600 RPM
Full Throttle RPM Range	5200-6000
Fuel	Unleaded Gasoline, 87 Octane min.

Always verify specifications against your owner's manual for your specific serial number range.

Common Issues & Recommended Parts

Below are common maintenance scenarios for the Mercury 250XB (3.0L EFI):

Water Pump / Overheating: If the tell-tale stream is weak or absent, the water pump impeller likely needs replacement. Inspect annually or every 100 hours. → Recommended: Water Pump Impeller Kit
Engine Oil / Maintenance Light: 4-stroke engines require regular oil and filter changes. Use marine-grade oil rated for your engine. Change every 100 hours or annually. → Recommended: Oil Filter, Engine Oil
Fuel Injector Issues (EFI models): Rough idle or misfires may indicate clogged fuel injectors. Use fuel stabilizer and clean injectors periodically. → Recommended: Fuel Injector, Fuel Filter
Gear Case Oil Leak: Check lower unit seals if gear oil appears milky (water contamination). Replace seals and gaskets during lower unit service. → Recommended: Lower Unit Seal Kit, Drain Plug Gaskets
Anode Corrosion: Inspect sacrificial anodes regularly, especially in saltwater. Replace when 50% depleted to protect against galvanic corrosion. → Recommended: Zinc/Aluminum Anode Kit

Parts Diagrams & OEM Part Numbers

Expand the sections below to view detailed exploded parts diagrams and find the exact OEM replacement components for your Mercury 250XB (3.0L EFI).

▶ACCESSORIES (1 parts)

Ref	OEM Part #	Part Name
-	79-895288A23	GAUGE KIT, Water Pressure (2-30 PSI) White Face, Black Graduation, White Bezel

▶ANCHOR BRACKET/THROTTLE LINKAGE (30 parts)

Ref	OEM Part #	Part Name
1	87-8M0052931	SWITCH
2	10-82470620	SCREW, (M3.5 x 20)
3	824010T05	BRACKET
4	10-42975	DRIVE SCREW
5	824016	LATCH
6	824015	CUP, Barrel Retainer
7	10-82155025	SCREW, (M8 x 25) Stainless Steel
8	23-824013	BUSHING
9	23-812707	BUSHING
10	24-824014	SPRING
11	8240111	GUIDE, Roller
12	8142392	CAM
13	23-26856	BUSHING
14	11-401386	NUT, (M6) Stainless Steel
15	825377	LINK, Throttle
16	23-8M0215006	BUSHING
17	826205	BRACKET, Oil Link
18	878190	LINK
19	10-82155025	SCREW, (M8 x 25) Stainless Steel
20	11-401388	NUT, (M8) Stainless Steel
21	8M0040987	LEVER
22	10-81893435	SCREW, (M8 x 35)
23	12-36042	WASHER
24	42927	INSERT
25	23-821113	BUSHING
26	11-401386	NUT, (M6) Stainless Steel
27	10-40124	SCREW, (M6 x 55)
28	11-400212	NUT, (M6) Stainless Steel
29	42942	CAP
30	12-35459	WASHER

▶BLEED SYSTEM (14 parts)

Ref	OEM Part #	Part Name
-	61-848700A7	POWERHEAD ASSEMBLY
1	32-892024122	TUBING, (20.00 Feet Bulk) (Cut to 13-1/4 IN.) Comment: (Starboard)
2	22-768431	FITTING Comment: (Starboard)
3	21-8348041	CHECK VALVE Comment: (Starboard)
4	21-8282182	CHECK VALVE Comment: (Starboard)
5	32-892024122	TUBING, (20.00 Feet Bulk) (Cut to 5-1/4 IN.) Comment: (Starboard)
6	32-892024122	TUBING, (20.00 Feet Bulk) (Cut to 8-1/2 IN.) Comment: (Port)
7	32-892024122	TUBING, (20.00 Feet Bulk) (Cut to 9-1/2 IN.) Comment: (Port)
8	21-8282182	CHECK VALVE Comment: (Port)
9	21-8348041	CHECK VALVE Comment: (Port)
10	22-59169003	FITTING, Tee Comment: (Port)
11	32-892024122	TUBING, (20.00 Feet Bulk) (Cut to 5-1/4 IN.) Comment: (Port)
12	32-892024122	TUBING, (20.00 Feet Bulk) (Cut to 1 IN.) Comment: (Port)
13	32-892024122	TUBING, (20.00 Feet Bulk) (Cut to 16 IN.) Comment: (Port)

▶BOTTOM COWL (17 parts)

Ref	OEM Part #	Part Name
1	4009-818448A1	BOTTOM COWL Comment: (PORT)
2	4009-818447A1	BOTTOM COWL Comment: (STARBOARD)
3	8M0109217	SEAL, Cowl (41.00 Inches)
4	10-82130040	SCREW, (M6 x 40)
5	10-824868	SCREW, (M6 x 75)
6	889740A02	FRONT HANDLE, Black
7	23-335891	BUSHING
8	25-48462	O-RING, (.614 x .070)
9	8219423	PAWL
10	12-69057	WASHER, (.281 x .734 x .063)
11	11-401366	NUT, (M6) Stainless Steel
12	10-8214281	SCREW, (#10-16 x .625)
13	54-822873	CLIP
14	87-8M0042301	SWITCH ASSEMBLY
15	54-822024	CLAMP
16	54-822023	CLAMP
17	10-92799	SCREW, (#10-16 x 1.12)

▶CRANKSHAFT, PISTONS - AND CONNECTING RODS (26 parts)

Ref	OEM Part #	Part Name
-	61-848700A7	POWERHEAD ASSEMBLY
1	482-9784A11	CRANKSHAFT ASSEMBLY
2	NSS	NOT SOLD SEPARATE, Wear Sleeve
3	30-67923T	BEARING, Ball (LOWER)
4	53-67446	RING
5	43-19301	GEAR
6	39-843198T01	RING
7	28-91800	KEY, Woodruff
8	25-35126	O-RING, (.859 x .139)
9	31-88270A02	RACE ASSEMBLY Comment: SN# 0T325117 & Up
10	NSS	NOT SOLD SEPARATE, Roller Bearing Comment: SN# 0T325117 & Below
11	700-858294T2	PISTON Comment: (PORT)
12	40-841202	RING
13	39-827179A12	RING SET, Piston
14	NSS	NOT SOLD SEPARATE, PISTON RING (SECOND)
15	600-8M0125869	CONNECTING ROD ASSEMBLY
16	10-94320	SCREW, (.375-24 x 1.250)
17	31-844338A01	BEARING/CAGE KIT
18	NSS	NOT SOLD SEPARATE, Bearing
19	12-88263	THRUST WASHER
20	29-8M0204715	NEEDLE, Roller Bearing
21	31-816773A2	BEARING ASSEMBLY (UPPER)
22	26-859093	SEAL
23	25-823683	O-RING, (1.989 x .070)
24	12-33001	WASHER, (.641 x 1.250 x .190)
25	11-42979	NUT, (M16)

▶CYLINDER BLOCK AND END CAP (55 parts)

Ref	OEM Part #	Part Name
-	61-848700A7	POWERHEAD ASSEMBLY
1	885-9811A56	CYLINDER BLOCK
2	16-903509	STUD, (M10 x 1.5 x 64)
3	16-8154431	STUD, (M10 x 1.5 x 155)
4	22-328022	PLUG, Pipe (.125-27) Brass
5	8248577	DEFLECTOR
6	21-8781051	CHECK VALVE
7	17-43044	PIN, Dowel - Without Hole (.375 x .625)
8	8215832	PIN, Special
9	10-81893435	SCREW, (M8 x 35)
10	10-82446180	SCREW, (M10 x 80)
11	17-8M0036405	PIN
12	19-850309001	PLUG
13	21-426585	CHECK VALVE
14	21-8159234	CHECK VALVE
15	32-892024122	TUBING, (20.00 Feet Bulk) (Cut to 22-1/2 IN.)
16	32-892024122	TUBING, (20.00 Feet Bulk) (Cut to 3-3/4 IN.)
17	22-77863A1	FITTING ASSEMBLY
18	8217621	TIMING POINTER
19	10-82130012	SCREW, (M6 x 12)
20	54-816311T	TIE STRAP, (8.00 Inches)
21	32-826544A1	TUBING KIT
22	22-687271	FITTING, (.250-18) 90 Degree - Brass
23	12-8M0214963	WASHER, (.406 x .750 x .105) Stainless Steel
24	11-4013610	NUT, (M10) Stainless Steel
25	8256751	BRACKET
26	10-82130012	SCREW, (M6 x 12)
27	8211051	BRACKET, Alternator
28	10-81893450	SCREW, (M8 x 50)
29	8212251	BRACKET
30	10-82130012	SCREW, (M6 x 12)
31	822486	BRACKET, Guide
32	821909	SENSOR
33	10-82104510	SCREW, (M5 x 10)
34	818574	SEAL, Cylinder Head
35	812851A16	CYLINDER HEAD
36	25-818573	O-RING Comment: SN# 0T234999 & Below
37	833072003	THERMOSTAT, 62Â° Celsius (143Â° Fahrenheit)
38	27-8M0204714	GASKET, Thermostat
39	19801A1	THERMOSTAT COVER
40	22-8167811	ELBOW
41	32-77653101	HOSE, (48.00 Inches Bulk) (Cut to 20-1/2 IN.) Comment: (STARBOARD)
42	10-82446090	SCREW, (M8 x 90)
43	10-8M0045380	SCREW, (M8 x 50)
44	13536A14	SENSOR ASSEMBLY, Temperature
45	137151	RETAINER
46	10-81893414	SCREW, (M8 x 14)
47	1171-9787A4	END CAP ASSEMBLY
48	25-62700	O-RING, (3.237 x .103)
49	26-8308981	SEAL
50	10-82130020	SCREW, (M6 x 20)
51	8261211	BRACKET
52	10-48408	SCREW, (#10-16 x .500)
53	10-82130012	SCREW, (M6 x 12)
54	8266241	CLAMP

▶DRIVESHAFT HOUSING AND EXHAUST TUBE (28 parts)

Ref	OEM Part #	Part Name
-	NSS	NOT SOLD SEPARATE, Strainer
1	3518-832937A06	HOUSING ASSEMBLY, Driveshaft
2	16-8M0008031	STUD, (M12 x 52)
3	10-857136	SCREW, (M12 x 35), External Hex
4	25-8331231	GROMMET
5	12-4002321	WASHER, (12.80 mm x 24.0 mm x 2.4 mm) Stainless Steel
6	11-4013812	NUT, (M12) Stainless Steel
7	19-64649	PLUG
8	10-898834	SCREW, (M14 x 178)
9	88238A10	CABLE ASSEMBLY, Ground
10	12-815432	WASHER, (.562 x 2.00 x .125)
11	8M0055931	MOUNT
12	12-825190	WASHER
13	88238A10	CABLE ASSEMBLY, Ground
14	10-41508	SCREW, (.250-20 x .500) Stainless Steel
15	11-896602	NUT
16	8186442	CLAMP
17	10-84036240	SCREW, (M8 x 40)
18	12-847541	WASHER
19	13-72521	LOCKWASHER, Internal Tooth
20	8M0001136	COVER, Black
21	10-69079	SCREW, (#10-16 x .440)
22	8329321	SEAL
23	833116A7	TUBE ASSEMBLY, Exhaust
24	10-81893435	SCREW, (M8 x 35)
25	32-8M0042785	TUBE, Water
26	832940001	SEAL
27	8329391	CLAMP

▶DUAL CABLE ATTACHING KIT (12 parts)

Ref	OEM Part #	Part Name
-	92876A8	ATTACHING KIT, Steering Comment: (SINGLE)
1	41055A1	BRACKET ASSEMBLY
2	71565A2	TUBE ASSEMBLY
3	25-48462	O-RING, (.614 x .070)
4	13-821203	LOCKWASHER
5	11-8M0041651	NUT, (.875-14)
6	10-38601	SCREW, (.250-28 x 1.250)
7	13-78968	LOCKWASHER, Internal (.250)
8	850791T	COUPLER
9	10-73732	SCREW, (.375-24 x 1.120)
10	12-37828	WASHER, (.390 x .625 x .062) Stainless Steel
11	11-8M0204726	NUT, (.375-24) Stainless Steel

▶ELECTRICAL COMPONENTS (47 parts)

Ref	OEM Part #	Part Name
1	825296T1	PLATE, Electrical Mounting
2	10-82129114	SCREW, (M6 x 14)
3	827509T7	CDM MODULE ASSEMBLY
4	84-857124A1	CABLE ASSEMBLY, Hi-Tension
5	85-857074A1	BOOT/TERMINAL KIT
6	10-82129116	SCREW, (M6 x 16)
7	54-816311T	TIE STRAP, (8.00 Inches)
8	33-941	SPARK PLUG
9	10-81893435	SCREW, (M8 x 35)
10	12-49436	WASHER
11	25-825380001	GROMMET
12	23-19064	BUSHING
13	83004419S	ECU, Engine Control Unit (CDI)
14	83004615T	ECU, Engine Control Unit (EFI)
15	10-82129145	SCREW, (M6 x 45)
16	54-826188	CLAMP
17	10-82104520	SCREW, (M5 x 20)
18	84-825763A5	HARNESS ASSEMBLY (EFI)
19	13541	PLUG, Male
20	84-825433A11	HARNESS ASSEMBLY, Ignition
21	8M0207773	RELAY ASSEMBLY
22	25-818967	GROMMET
23	828102	BRACKET
24	23-8M0214955	BUSHING
25	NSS	NOT SOLD SEPARATE, DECAL, Trim Relay
26	84-826802A2	HARNESS ASSEMBLY, Trim
27	84-88439A34	CABLE ASSEMBLY, Positive - Battery
28	84-88439A24	CABLE ASSEMBLY, Negative - Battery
29	84-827356A2	HARNESS ASSEMBLY (26 IN.)
30	8216091	COVER
31	10-82239320	SCREW, (M5 x 20)
32	88-812619	FUSE, Yellow - 20 Ampere
33	88-19637	SOCKET, Fuse
34	84-93388A8	CABLE ASSEMBLY, (12.5 Inchs) Black
35	8212282	PLATE, Solenoid Mounting
36	10-82155025	SCREW, (M8 x 25) Stainless Steel
37	10-82129125	SCREW, (M6 x 25)
38	84-88807A16	CABLE ASSEMBLY, (4.00 Inches) Black
39	86-45915	TERMINAL BLOCK
40	10-878608	SCREW, (#10-16 x .500)
41	10-878607	SCREW, (#10-16 x .375)
42	89-817109A2	SOLENOID ASSEMBLY, (#10-32 / .3125-18 Terminals)
43	25-822179	GROMMET
44	23-8M0214955	BUSHING
45	13-53166	LOCKWASHER, (.312)
46	11-8M0204668	NUT, (.312-18)
47	10-32,11-45076	NUT, Brass

▶EXHAUST PLATE (46 parts)

Ref	OEM Part #	Part Name
-	61-848700A7	POWERHEAD ASSEMBLY
1	840192T5	PLATE, Exhaust
2	27-8329335	GASKET
3	27-8329344	GASKET (LOWER)
4	24-64878	SPRING
5	8M0043157	SEAL
6	10-81893435	SCREW, (M8 x 35)
7	65663A2	COVER ASSEMBLY
8	65664A1	PLATE ASSEMBLY
9	27-88907003	GASKET
10	10-69570	SCREW, (#10-16 x .750)
11	12-76451	WASHER
12	648771	DIAPHRAGM
13	814189	POPPET
14	25-814191	GROMMET
15	814190	CARRIER
16	10-81893435	SCREW, (M8 x 35)
17	22-34982	CONNECTOR
18	22-782792	FITTING, Elbow 45 Degree (1.25)
19	22-821975	ELBOW, 45 Degree
20	821255	BOOT, Idle Exhaust
21	54-816311T	TIE STRAP, (8.00 Inches)
22	32-8M0108355	HOSE, (57.00 Inches Bulk) (Cut to 2-1/2 IN.)
23	22-8M0077650	FITTING, Tell-Tale
24	19-821908	PLUG
25	12-821915	WASHER
26	8219631	CHECK VALVE
27	25-30641	O-RING, (.299 x .103)
28	22-821952	FITTING
29	32-821976	HOSE
30	21-817519A1	CHECK VALVE ASSEMBLY, Drain
31	17-43044	PIN, Dowel - Without Hole (.375 x .625)
32	11-401386	NUT, (M6) Stainless Steel
33	12-35459	WASHER
34	883142A03	SHIFT LINK Comment: SN# 0T430431 & Up
35	8240121	ROLLER Comment: SN# 0T430431 & Up
36	11-401386	NUT, (M6) Stainless Steel
37	23-42994	BUSHING
38	8M0036408	SHIFT SHAFT, Upper
39	23-48237	BUSHING
40	25-12602002	GROMMET
41	43585	COUPLING
42	22-8M0204679	FITTING, Pipe - Brass (.750-14)
43	23-840193	SPACER
44	883142A03	SHIFT LINK Comment: SN# 0T430430 & Below
45	824012	ROLLER Comment: SN# 0T430430 & Below

▶FLYWHEEL/STATOR (12 parts)

Ref	OEM Part #	Part Name
1	11-401386	NUT, (M6) Stainless Steel
2	19-45907	PLUG, Yellow
3	272-821033T2	FLYWHEEL
4	398-821935A5	STATOR
5	10-82494830	SCREW, (M6 x 30)
6	821663A1	ALTERNATOR
7	10-82446155	SCREW, (M10 x 55)
8	10-82130140	SCREW, (M10 x 40)
9	12-796431	WASHER
10	11-4013610	NUT, (M10) Stainless Steel
11	57-49756Q1	V BELT
12	12-17457	WASHER

▶FUEL MANAGEMENT SYSTEM (33 parts)

Ref	OEM Part #	Part Name
-	825818A14	MANAGEMENT ASSEMBLY, Fuel
1	827693T4	THROTTLE BODY
2	8090571	JOINT KIT, Fuel Pipe
3	10-8276983	SCREW KIT, Fuel Rail
4	150291	O-RING KIT
5	814233T1	FMA JOINT KIT
6	8090591	SCHRADER VALVE KIT
7	32-827694A02	TUBING KIT
8	32-897992A01	TUBING KIT
9	8090843	SHAFT, Throttle Comment: (TOP)
10	8090842	SHAFT KIT, Throttle Comment: (BOTTOM)
11	827697A1	LEVER KIT, Link
12	154441	LINK
13	8276991	FUEL RAIL
14	84-154432	HARNESS KIT
15	8276921	COVER
16	26-187921	SEAL
17	827696	RETAINER KIT
18	809093	BRACKET KIT, TPS
19	805225A1	INJECTOR KIT
20	677483	ROLLER
21	28-89694	KEY
22	821153	COUPLING
23	821664	SENSOR, Throttle Position
24	10-4005685	SCREW, (M4 x 10)
25	8,13-26995	LOCKWASHER, Stainless Steel
26	12-30164	WASHER, (.192 x .375 x .0312) Stainless Steel
27	13221T01	SENSOR ASSEMBLY, Temperature
28	10-4005685	SCREW, (M4 x 10)
29	8,13-26995	LOCKWASHER, Stainless Steel
30	25-45711	O-RING, (.612 x .103)
31	10-40132	SCREW, (M8 x 125)
32	12-8M0042642	WASHER, (.323 x .563 x .063) Stainless Steel

▶FUEL PUMP (29 parts)

Ref	OEM Part #	Part Name
-	61-848700A7	POWERHEAD ASSEMBLY
1	14360A78	PUMP KIT, Fuel
2	NSS	NOT SOLD SEPARATE, Disk Check Valve
3	NSS	NOT SOLD SEPARATE, Diaphragm
4	NSS	NOT SOLD SEPARATE, Retainer
5	NSS	NOT SOLD SEPARATE, Spring
6	NSS	NOT SOLD SEPARATE, Cap
7	NSS	NOT SOLD SEPARATE, Spring
8	NSS	NOT SOLD SEPARATE, Cap
9	NSS	NOT SOLD SEPARATE, Diaphragm
10	NSS	NOT SOLD SEPARATE, GASKET, Boost
11	NSS	NOT SOLD SEPARATE, GASKET, Pulse
12	27-8M0204705	GASKET
13	144303	BASE
14	987752	PLATE
15	10-82104540	SCREW, (M5 x 40)
16	NSS	NOT SOLD SEPARATE, DECAL, Assembled in Mexico
17	10-82130050	SCREW, (M6 x 50)
18	22-629101	FITTING, Elbow - 90 Degree (.125-27)
19	54-816311T	TIE STRAP, (8.00 Inches)
20	32-8M0108349	TUBING, (.312) (70.00 Inches Bulk) (Cut to 17 IN.)
21	32-8M0108349	TUBING, (.312) (70.00 Inches Bulk) Comment: (Cut to 17 IN.)
22	22-822769	CONNECTOR
23	35-18458T4	FILTER KIT
24	8M0204710	PROBE
25	13170A3	BASE
26	22-136071	ELBOW
27	10-82130030	SCREW, (M6 x 30)
28	22-89771Q2	CONNECTOR, (.250-18)

▶GEAR HSG.(DRIVESHAFT)(STD)(S/N-0T234999 & BELOW) (47 parts)

Ref	OEM Part #	Part Name
-	47-8M0100526	REPAIR KIT, Water Pump Impeller
1	1689-840470T5	GEAR HOUSING ASSEMBLY (BASIC)
2	17-379721	PIN
3	821526001	FILLER BLOCK
4	97-826134Q	ANODE
5	10-4000333	SCREW, (M6 x 40)
6	11-401386	NUT, (M6) Stainless Steel
7	31-42647A1	BEARING ASSEMBLY, Roller
8	17-43044	PIN, Dowel - Without Hole (.375 x .625)
9	10-79953Q04	SCREW KIT, (.375-16 x .250) Drain
10	12-191833	WASHER
11	22-85822A10	CONNECTOR ASSEMBLY
12	56762	TIE STRAP, (4.00 Inches)
13	NSS	NOT SOLD SEPARATE, Pinion Gear Comment: (PART OF 43-828168T3)
14	12-92721	WASHER
15	11-35921	NUT, (.625-18)
16	23-815921A4	BUSHING ASSEMBLY
17	26-8M0204708	SEAL, Oil
18	25-8M0214927	O-RING, (.799)
19	10-82130016	SCREW, (M6 x 16)
20	12-77674	WASHER
21	824145	SHIFT SHAFT (LOWER)
22	45-848831	DRIVESHAFT
23	28-8M0204723	KEY
24	15-8M0063268	SHIM ASSEMBLY
25	31-8M0146553	BEARING, Tapered Roller
26	NSS	NOT SOLD SEPARATE, Cup
27	15-42637A1	SHIM SET
28	31-8M0146566	BEARING, Roller
29	NSS	NOT SOLD SEPARATE, Cup
30	8245191	RETAINER
31	8M0214948	CARRIER ASSEMBLY
32	25-8M0142854	O-RING, (2.175 x .175)
33	26-8M0214939	SEAL, Oil
34	26-8M0214939	SEAL, Oil
35	817275A1	PUMP ASSEMBLY, Water
36	26-816575A2	SEAL KIT
37	27-430331	GASKET
38	27-8172771	GASKET
39	8M0204709	FACEPLATE
40	47-43026T2	IMPELLER
41	10-82130016	SCREW, (M6 x 16)
42	832942A1	COUPLING ASSEMBLY
43	25-8M0204645	O-RING, (.796 x .139)
44	25-8M0204654	O-RING, (1.046)
45	45-848832A1	DRIVESHAFT ASSEMBLY
46	823902	COUPLING

▶GEAR HSG.(DRIVESHAFT)(STD)(S/N-0T235000 & UP) (51 parts)

Ref	OEM Part #	Part Name
-	817275A5	REBUILD KIT, Water Pump
1	1689-840470T5	GEAR HOUSING ASSEMBLY, Basic
2	17-379721	PIN
3	821526001	FILLER BLOCK
4	859402	PITOT TUBE
5	97-826134Q	ANODE
6	10-4000333	SCREW, (M6 x 40)
7	11-401386	NUT, (M6) Stainless Steel
8	31-42647A1	BEARING ASSEMBLY, Roller
9	17-43044	PIN, Dowel - Without Hole (.375 x .625)
10	32-85944975	TUBING, (72.00 Inches Bulk) (Cut to 7 IN.)
11	22-881866	FITTING
12	858934	COVER
13	27-858935	GASKET
14	26-8M0204708	SEAL, Oil
15	25-8M0214927	O-RING, (.799)
16	10-82130016	SCREW, (M6 x 16)
17	12-92721	WASHER
18	11-35921	NUT, (.625-18)
19	NSS	NOT SOLD SEPARATE, Pinion Gear Comment: (PART OF 43-828168T3)
20	10-79953Q04	SCREW KIT, (.375-16 x .250) Drain
21	12-191833	WASHER
22	12-77674	WASHER
23	824145	SHIFT SHAFT (LOWER)
24	45-881938	DRIVESHAFT
25	15-8M0063268	SHIM ASSEMBLY
26	31-8M0146553	BEARING, Tapered Roller
27	NSS	NOT SOLD SEPARATE, Cup
28	28-8M0204723	KEY
29	15-42637A1	SHIM SET
30	31-8M0146566	BEARING, Roller
31	NSS	NOT SOLD SEPARATE, Cup
32	8245191	RETAINER
33	8M0214948	CARRIER ASSEMBLY Comment: SN# 0T429944 & Below
34	8M0192207	CARRIER ASSEMBLY Comment: SN# 0T429945 & Up
35	10-82130016	SCREW, (M6 x 16) Comment: SN# 0T429945 & Up
36	25-8M0142854	O-RING, (2.175 x .175)
37	26-8M0214939	SEAL, Oil
38	26-8M0214939	SEAL, Oil
39	817275A1	PUMP ASSEMBLY, Water
40	26-816575A2	SEAL KIT
41	27-430331	GASKET
42	27-8172771	GASKET
43	8M0204709	FACEPLATE
44	47-43026T2	IMPELLER
45	10-82130016	SCREW, (M6 x 16)
46	832942A1	COUPLING ASSEMBLY
47	25-8M0204645	O-RING, (.796 x .139)
48	25-8M0204654	O-RING, (1.046)
49	45-848832A1	DRIVESHAFT ASSEMBLY
50	823902	COUPLING

▶GEAR HSG.(PROP SHAFT)(STD)(S/N-0T234999 & BELOW) (38 parts)

Ref	OEM Part #	Part Name
-	26-816575A6	SEAL KIT, Gear Housing
1	1689-840470T5	GEAR HOUSING ASSEMBLY (BASIC)
47	8M0226861	SHIFT CRANK
48	8M0235940	SPOOL ASSEMBLY
49	NSS	NOT SOLD SEPARATE, Shift Pool
50	NSS	NOT SOLD SEPARATE, Cotter Pin
51	NSS	NOT SOLD SEPARATE, Sleeve
52	15-47397A1	SHIM SET
53	43-859321T04	GEAR SET, Forward/Pinion Comment: (1.75:1)
54	31-828437A2	BEARING ASSEMBLY
55	NSS	NOT SOLD SEPARATE, Cup
56	31-30895T	BEARING, Needle
57	53-856823	RING, Retaining
58	24-78962	SPRING
59	52-848878T	CLUTCH
60	17-78909	PIN, Detent
61	17-848838	PIN, Cross
62	44-848829	PROPELLER SHAFT
63	43-8M0192235	GEAR, Reverse Comment: (1.75:1)
64	23-8241081	THRUST SPACER
65	681001	RING, Thrust
66	30-88957T	BEARING, Ball
67	25-8M0214920	O-RING
68	848840A1	CARRIER ASSEMBLY, Bearing
69	31-817072	BEARING, Roller
70	26-815565	SEAL, Oil
71	53-817071	RING, Snap
72	22-8M0058389	FITTING KIT, Magnetic, Plug Fill/Drain
73	12-191833	WASHER
74	28-30281	KEY
75	14-79447	TAB WASHER
76	8M2011027	RETAINER
77	11-52707Q1	PROP NUT KIT, (.750-16)
78	13-423511	LOCKWASHER, Toothed
79	832066A1	PLATE KIT, Water Inlet
80	10-188642	SCREW, (#8-32 x .500)
81	97-76214Q5	ANODE KIT
82	10-66024	SCREW, (.437-14 x 1.75)

▶GEAR HSG.(PROP SHAFT)(STD)(S/N-0T235000 & UP) (36 parts)

Ref	OEM Part #	Part Name
-	26-816575A6	SEAL KIT, Gear Housing
1	1689-840470T5	GEAR HOUSING ASSEMBLY, Basic
51	8M0226861	SHIFT CRANK
52	8M0235940	SPOOL ASSEMBLY
53	NSS	NOT SOLD SEPARATE, Shift Pool
54	18-469501	COTTER PIN
55	NSS	NOT SOLD SEPARATE, Sleeve
56	15-47397A1	SHIM SET
57	43-859321T04	GEAR SET, Forward/Pinion
58	31-828437A2	BEARING ASSEMBLY
59	NSS	NOT SOLD SEPARATE, Cup
60	53-856823	RING, Retaining
61	31-30895T	BEARING, Needle
62	24-78962	SPRING
63	52-848878T	CLUTCH
64	17-78909	PIN, Detent
65	17-848838	PIN, Cross
66	44-848829	PROPELLER SHAFT
67	43-8M0192235	GEAR, Reverse
68	23-8241081	THRUST SPACER
69	681001	RING, Thrust
70	30-88957T	BEARING, Ball
71	25-8M0214920	O-RING
72	848840A1	CARRIER ASSEMBLY, Bearing
73	31-817072	BEARING, Roller
74	26-815565	SEAL, Oil
75	53-817071	RING, Snap
76	22-8M0058389	FITTING KIT, Magnetic, Plug Fill/Drain
77	12-191833	WASHER
78	28-30281	KEY
79	14-79447	TAB WASHER
80	8M2011027	RETAINER
81	11-52707Q1	PROP NUT KIT, (.750-16)
82	13-423511	LOCKWASHER, Toothed
83	97-76214Q5	ANODE KIT
84	10-66024	SCREW, (.437-14 x 1.75)

▶INSTRUMENTATION (19 parts)

Ref	OEM Part #	Part Name
1	84-86323A5	CABLE ASSEMBLY, (1.50 Feet) Purple
2	79-895292Q41	GAUGE, Power Trim, White Face, Black Graduation, Black Bezel
3	79480	BRACKET
4	88-72729	LIGHT BULB, Wedge Base (14V - .19W)
5	88-79888	SOCKET, Light Bulb
6	8-32,11-26419	NUT, Brass
7	68878A6	HORN ASSEMBLY, Buzzer Alarm
8	68879	COVER
9	23-8M0084588	SPACER
10	12-26427	WASHER
11	10-35401	SCREW, (#10 x 1.00)
12	84-86396A8	HARNESS ASSEMBLY, Tachometer (5.00 Feet)
13	79-859698A1	WARNING GAUGE KIT
14	88-15163	LAMP
15	88-79888	SOCKET, Light Bulb
16	8,13-825361	LOCKWASHER, Star
17	8-32,11-26419	NUT, Brass
18	850020	CLAMP
19	84-827752A1	CABLE ASSEMBLY, (20.00 Feet)

▶KEY SWITCH ASSEMBLY (12 parts)

Ref	OEM Part #	Part Name
-	8949112	KEY, Ignition (2F)
1	84-816626A20	HARNESS ASSEMBLY, Key Switch (20.00 Feet)
2	90468A1	COVER ASSEMBLY, Key
3	76424	BRACKET
4	16-55422	STUD, (#10-32 x 2.00)
5	12-24676	WASHER, (.200 x .440 x .032)
6	10-32,11-68219	NUT, Stainless Steel
7	816479A3	PLATE KIT
8	87-88107A5	SWITCH KIT, Key (SEE CHART BELOW FOR KEY)
9	11-879755	NUT, Special - Black Nylon
10	84-8M0210763	ALARM ASSEMBLY, Audio Warning
11	23-812711	SPACER, (.250)

▶OIL INJECTION COMPONENTS (42 parts)

Ref	OEM Part #	Part Name
-	1257-8742A22	TANK ASSEMBLY, Remote Oil Comment: (USE WITH DESIGN II BRACKET)
1	1270-818456A1	TANK ASSEMBLY, Oil
2	23-8260841	SPACER
3	10-58376	SCREW, (.164-18 x .375)
4	12-72761	WASHER, (.203 x .562 x .060) Stainless Steel
5	NSS	NOT SOLD SEPARATE, DECAL, Oil Tank
6	36-814449A3	CAP ASSEMBLY
7	27-42999T	GASKET
8	87-12886A7	SWITCH ASSEMBLY
9	23-19064	BUSHING
10	25-825380001	GROMMET
11	12-49436	WASHER
12	10-81893435	SCREW, (M8 x 35)
13	32-8M0108355	HOSE, (57.00 Inches Bulk)
14	22-8M0207780	FITTING
15	10-82104530	SCREW
16	815536T1	PUMP, Oil
17	25-11379	O-RING
18	25-48462	O-RING, (.614 x .070)
19	23-817631	BEARING, Driven Gear
20	43-430204	GEAR, Driven
21	816974	BEARING, Thrust
22	10-82104520	SCREW, (M5 x 20)
23	54-816311T	TIE STRAP, (8.00 Inches)
24	32-82381455	TUBING, (25.00 Inches Bulk) (Cut to 8-3/4 IN.)
25	32-82381335	TUBING, (15.00 Inches Bulk) (Cut to 10 IN.)
26	1257-87421	TANK
27	816190A4	SENDER ASSEMBLY, Oil Level
28	25-11332	O-RING, (2.225 x .210)
29	36-43298A2	CAP ASSEMBLY
30	25-11332	O-RING, (2.225 x .210)
31	NSS	NOT SOLD SEPARATE, Insert
32	32-99802	TUBE
33	32-99439	HOSE, (114.00 Inches)
34	12335A1	BRACKET KIT Comment: (DESIGN I)
35	884481A1	BRACKET KIT Comment: (DESIGN II)
36	12320	BRACKET
37	10-79968	SCREW, (#12-11 x .750)
38	12323A1	CORD/HOOK KIT
39	32-858853	HOSE
40	22-858955	CONNECTOR
41	54-816311T	TIE STRAP, (8.00 Inches)

▶POWER TRIM COMPONENTS(CAST PUMP HOUSING) (38 parts)

Ref	OEM Part #	Part Name
-	855998A11	POWER TRIM, Complete
1	878265A4	TRIM MOTOR
2	NSS	NOT SOLD SEPARATE, Armature
3	NSS	NOT SOLD SEPARATE, End Frame
4	10-82494830	SCREW, (M6 x 30)
5	13-400256	LOCKWASHER, (M6)
6	8782451	COUPLING
7	878410A1	PO CHECK KIT
8	893929A01	MANUAL RELEASE ASSEMBLY
9	8M0142997	SHAFT KIT (Incls. Ref. #26)
10	17-878267	PIN
11	878235A03	TILT CYLINDER ASSEMBLY
12	878239A02	GUIDE KIT (Incls. Ref. #26)
13	8M0142999	O-RING KIT (Incls. Ref. #26)
14	8M0168219	SHOCK ROD KIT (Incls. Ref. #26)
15	8M0143000	PISTON ASSEMBLY, Memory
16	878406A02	REPAIR KIT, Check Valve (Incls. Ref. #26)
17	878414T01	PISTON ASSEMBLY
18	878413A1	PISTON ASSEMBLY
19	1100-8M0021648	GUIDE ASSEMBLY
20	878264A1	RESERVOIR KIT
21	19-811613	PLUG ASSEMBLY
22	10-4000327	SCREW, (M6 x 14)
23	12-4002315	WASHER
24	892251A01	PUMP KIT
25	878408A1	REPAIR KIT, Power Trim
26	17-821539	PIN, Trilobe
27	10-858771	SCREW, (M10 x 30)
28	12-4002319	WASHER
29	97-818298Q1	ANODE KIT
30	10-8M0204707	SCREW, (M6 x 25)
31	12-8M0204649	WASHER, (.281 x .500 x .060) Stainless Steel
32	99625002	SHAFT
33	8M0084613	C WASHER
34	54-22875	CLIP
35	10-878608	SCREW, (#10-16 x .500)
36	32-828547353	CONDUIT, (.350 Inside Diameter x 3.00 Feet Bulk)
37	54-816311T	TIE STRAP, (8.00 Inches)

▶POWER TRIM COMPONENTS(REMOVABLE PUMP HOUSING) (38 parts)

Ref	OEM Part #	Part Name
-	855998A11	POWER TRIM ASSEMBLY, Complete
1	811604F	MANIFOLD ASSEMBLY
2	22-56800	PLUG, Pipe (.0625-27)
3	880952A03	CYLINDER ASSEMBLY, Tilt
4	823553T	ROD, Trim Piston
5	878239A02	GUIDE KIT
6	811607A1	REPAIR KIT
7	811610A1	CHECK VALVE KIT
8	1100-8M0021648	GUIDE ASSEMBLY
9	878414T01	PISTON ASSEMBLY Comment: (STARBOARD)
10	35-12184A1	TRIM FILTER ASSEMBLY
11	893929A01	MANUAL RELEASE ASSEMBLY
12	53-815949001	E RING
13	811612A3	O-RING KIT
14	811617T1	PUMP
15	19-811613	PLUG ASSEMBLY
16	10-4000327	SCREW, (M6 x 14)
17	12-4002315	WASHER
18	811611	COVER
19	828710	DRIVE JOINT
20	878265A4	TRIM MOTOR Comment: (BREAKDOWN ON POWER TRIM MOTOR )
21	10-811616	SCREW (SHORT)
22	8M0142997	SHAFT ASSEMBLY
23	22-56800	PLUG, Pipe (.0625-27)
24	17-878267	PIN, Groove
25	17-821539	PIN, Trilobe
26	99625002	SHAFT
27	97-818298Q1	ANODE KIT
28	10-8M0204707	SCREW, (M6 x 25)
29	12-8M0204649	WASHER, (.281 x .500 x .060) Stainless Steel
30	10-4000377	SCREW, (M10 x 30)
31	12-4002319	WASHER
32	54-26550	CLAMP
33	10-878608	SCREW, (#10-16 x .500)
34	8M0084613	C WASHER
35	37-435301	DECAL, Caution-Power Trim
36	32-828547353	CONDUIT, (.350 Inside Diameter x 3.00 Feet Bulk)
37	54-816311T	TIE STRAP, (8.00 Inches)

▶POWER TRIM MOTOR(REMOVABLE PUMP HOUSING) (4 parts)

Ref	OEM Part #	Part Name
-	878265A4	TRIM MOTOR
1	828714A1	BRUSH AND SEAL KIT
2	828713T1	ARMATURE KIT
3	828715A1	END FRAME (COMPLETE)

▶REED BLOCK/FLYWHEEL COVER (12 parts)

Ref	OEM Part #	Part Name
-	61-848700A7	POWERHEAD ASSEMBLY
1	54-49542	CLAMP
2	27-825815	GASKET
3	10-82130012	SCREW, (M6 x 12)
4	825178T4	ADAPTOR PLATE
5	827507	RETAINER
6	10-82130025	SCREW, (M6 x 25)
7	27-8141951	GASKET
8	8M0051202	REED BLOCK
9	10-4007420	SCREW, (M6 x 20)
10	825832	FLYWHEEL COVER
11	25-8M0153609	GROMMET

▶SERVICE/SUPPORT MATERIAL (1 parts)

Ref	OEM Part #	Part Name
-	37-804675A03	DECAL, EPA Label Information Comment: (2003)

▶STARTER MOTOR (17 parts)

Ref	OEM Part #	Part Name
1	50-898265009	STARTER MOTOR ASSEMBLY
2	8236392	DRIVE CAP
3	10-823641	THRU BOLT
4	823640T	DRIVE KIT
5	898265015	PINION
6	823638	ARMATURE
7	898265016	BRUSH/SPRING KIT
8	898265014	HOLDER
9	8119011	CAP, Commutator
10	F15158	SCREW
11	13-26992	LOCKWASHER, (.250) Stainless Steel
12	11-94330	NUT, (.250-20) Brass
13	13-26992	LOCKWASHER, (.250) Stainless Steel
14	11-20890	NUT, (.250-20)
15	10-81893450	SCREW, (M8 x 50)
16	23-824921	SPACER
17	37-8272822	DECAL, Warning, High Voltage

▶SWIVEL BRACKET AND STEERING ARM (27 parts)

Ref	OEM Part #	Part Name
1	1499-8M0102865	SWIVEL BRACKET ASSEMBLY, Black
2	25-8M0214926	O-RING
3	23-818764	BUSHING
4	23-816039	SPACER
5	26-87735	SEAL, Oil (LOWER)
6	22-8M0169589	FITTING, Grease
7	23-821207	BUSHING
8	12-816432	THRUST WASHER
9	814084F1	YOKE, Bottom
10	53-67684	RING, Retaining
11	8M0045383	STRIKER PLATE
12	13-58643	LOCKWASHER, (.375)
13	11-46335	NUT, (.375-24)
14	10-64014	SCREW, (.250-28 x .500)
15	8M0074846	SENDER ASSEMBLY, Trim
16	10-852368	SCREW, (#10-24 x .750)
17	10,13-26996	LOCKWASHER, Stainless Steel
18	12-89302	WASHER, (.203 x .406 x .040)
19	17-67706A55	SWIVEL PIN ASSEMBLY, Steering Arm
20	10-8M0000518	SCREW, (M12 x 175)
21	12-4002321	WASHER, (12.80 mm x 24.0 mm x 2.4 mm) Stainless Steel
22	11-896963	NUT, (M12)
23	92876A12	LINK ROD ASSEMBLY
24	10-849838	SCREW, (.375-24 x 1.250)
25	11-8M0204726	NUT, (.375-24) Stainless Steel
26	12-37828	WASHER, (.390 x .625 x .062) Stainless Steel
27	NSS	NOT SOLD SEPARATE, DECAL, Serial Overlaminate

▶TOOLS, SPECIAL (1 parts)

Ref	OEM Part #	Part Name
-	91-821571A1	GUIDE TOOL, Water Pump Alignment Pins Comment: (Gear Housing)

▶TOP COWL (19 parts)

Ref	OEM Part #	Part Name
1	4001-814277A61	TOP COWL ASSEMBLY, Black
2	821256T03	INLET, Air - Black
3	10-82130016	SCREW, (M6 x 16)
4	821250A1	SOUND BLANKET KIT
5	NSS	NOT SOLD SEPARATE, Sound Blanket (SIDE)
6	19-823865	CAP PLUG
7	821248	REAR LATCH HOOK
8	53-8237951	RING, Retaining
9	8M0207770	ROLLER
10	12-8M0204649	WASHER, (.281 x .500 x .060) Stainless Steel
11	11-401366	NUT, (M6) Stainless Steel
12	8M0036792	BRACKET, Front
13	815477	BUMPER, Latch
14	8155381	PIN, Roll
15	11-401366	NUT, (M6) Stainless Steel
16	12-8M0204649	WASHER, (.281 x .500 x .060) Stainless Steel
17	826639T	COVER
18	47341A11	ROPE AND HANDLE KIT, Manual Starting
19	37-804801A00	DECAL SET

▶Transom Brackets (18 parts)

Ref	OEM Part #	Part Name
1	3426-828334T03	BRACKET ASSEMBLY, Transom-Starboard
2	3425-828333T08	BRACKET ASSEMBLY, Transom-Port
3	22-8M0169588	FITTING, Grease Comment: (PORT)
4	826125A1	TILT TUBE
5	11-826135	NUT, (1.00-14) Brass/Nickel Plate
6	25-45711	O-RING, (.612 x .103)
7	13-88750	WASHER
8	11-826164	NUT, (.875-14)
9	10-8M0149747	SCREW, (.500-20 x 4.500)
10	12-8M0204648	WASHER, (1.5 x 3.05 x 0.13) Stainless Steel
11	11-91962	NUT, (.500-20)
12	8M0115104	LEVER ASSEMBLY
13	24-830899	SPRING, Tension
14	23-65830	NYLINER
15	24-830900	SPRING, Compression
16	99633	KNOB
17	17-99615	PIN, Groove
18	17-893709	PIN

▶VAPOR SEPARATOR (33 parts)

Ref	OEM Part #	Part Name
-	825818A14	MANAGEMENT ASSEMBLY, Fuel
1	8140111	BODY KIT
2	10-809091	SCREW KIT
3	809086	O-RING
4	21-424811	VALVE
5	809092	SCREW KIT, Mounting
6	10-809061	BOLT
7	13-400256	LOCKWASHER
8	12-8090621	WASHER
9	12-8090622	WASHER
10	25-88033	GROMMET
11	23-809078	COLLAR
12	15445	FLOAT KIT
13	15446	VALVE KIT, Float
14	8140101	COVER
15	22-809085	ELBOW KIT
16	10-8140761	SCREW KIT
17	809090	CONNECTION KIT, Electrical
18	32-897992A01	TUBING KIT
19	809087	ATTACHING KIT
20	814012T1	REGULATOR KIT, Fuel Pressure
21	809088T	PUMP KIT, Fuel
22	808504T1	STRAINER KIT
23	809089	FITTING KIT, Fuel Pump
24	150291	O-RING KIT
25	11-8237515	NUT, (M4)
26	11-400211	NUT, (M5) Stainless Steel
27	8,13-26995	LOCKWASHER, Stainless Steel
28	825762	SENSOR, MAP
29	10-82130012	SCREW, (M6 x 12)
30	37-804675A03	DECAL, EPA Label Information Comment: (2003)
31	NSS	NOT SOLD SEPARATE, DECAL, Caution (In Gear Idle)
32	37-881865	DECAL, Caution-Start in Gear Comment: (Start In Gear)

100-Hour / Annual Service Checklist

Regular maintenance keeps your Mercury 250XB (3.0L EFI) running reliably season after season. Most of these tasks can be performed with basic tools and the factory service manual.

Replace water pump impeller and inspect wear plate
Change engine oil and oil filter (check drain plug washer)
Replace spark plugs and check ignition timing
Drain and refill lower unit gear oil; inspect for water contamination
Inspect fuel lines, primer bulb, and fuel filter for deterioration
Check and replace sacrificial anodes (zinc or aluminum)
Inspect propeller for damage; check shaft seal and cotter pin
Check valve clearance (refer to service manual for specifications)
Lubricate all grease points (steering, tilt tube, shift linkage)
Inspect control cables and throttle/shift linkage for smooth operation

Pro Tip: Always flush the engine with fresh water after saltwater use — even a quick 10-minute flush significantly extends component life.
Pro Tip: Use fuel stabilizer in the tank before winter storage, and fog the cylinders to prevent internal corrosion during extended periods of non-use.

Popular Products

Popular Products

Popular Products

Mercury 250XB (3.0L EFI) (0G980600 THRU 0T800999) Parts & Diagrams

Categories

Refined By Clear all

Brand

Horsepower

Engine

Availability

Price

Need Help?

Images

Product

Price

Qty

Options