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Mercury Outboard Parts
Shop OEM and aftermarket Mercury outboard parts for maintenance, repair, troubleshooting, and complete engine rebuild projects. Browse Mercury marine parts by system, including cooling, fuel delivery, electrical and ignition, internal engine components, lower unit parts, steering, trim, and routine service items.
Pro Marine USA carries Mercury outboard engine parts for a wide range of 2-stroke, FourStroke, EFI, Optimax, Pro XS, SeaPro, and Verado applications. Use your engine horsepower, model, serial number, or OEM part number whenever possible to confirm fitment before ordering.
Shop Mercury Outboard Parts by System
- Complete Powerheads
- Control Cables & Boxes
- Cooling System
- Cowlings & Components
- Electrical System
- Engine Oil
- Engine Rebuild Kits
- Fuel & Carburetion System
- Intake System
- Internal Engine Components
- Lower Unit Components
- Oiling System
- Paints
- Service & Oil Change Kits
- Service Manuals
- Steering Systems
- Throttle Components
- Transom & Midsection
- Trim System
- Wizard Performance Parts
Find the Correct Mercury Outboard Part
Mercury outboard parts can vary by horsepower, engine family, model year, and serial number range. If you are unsure which component fits your engine, use the OEM parts lookup to locate the original Mercury part number from an engine diagram.
Once you have the OEM part number, search Pro Marine to find available genuine Mercury and aftermarket replacement options.
Use Our OEM Parts Lookup »Common Mercury Outboard Engine Families
Pro Marine supports many Mercury outboard applications across a wide horsepower range. Always confirm the engine serial number and model information before ordering parts.
- Portable and Midrange: Mercury 2.5HP through 60HP 2-stroke and FourStroke applications
- FourStroke and EFI: common 75HP through 300HP Mercury EFI and FourStroke platforms
- Pro XS: performance-oriented Mercury Pro XS outboards across multiple engine families
- Optimax: direct-injected 2-stroke Mercury Optimax engines, commonly 75HP through 250HP
- Verado: supercharged and naturally aspirated Mercury Verado applications from 135HP through current high-horsepower platforms
- SeaPro: commercial-duty Mercury SeaPro outboards used in professional and high-hour applications
Common Mercury Outboard Repair Areas
- Overheating: inspect the water pump, impeller, thermostat, poppet valve, cooling passages, and related cooling components.
- Hard starting or rough running: inspect fuel pumps, filters, injectors or carburetors, spark plugs, coils, sensors, and intake components.
- No spark or intermittent ignition: check ignition coils, stators, switch boxes, trigger assemblies, sensors, grounds, and wiring.
- Low compression or power loss: inspect pistons, rings, cylinders, bearings, gaskets, reeds, and internal engine components.
- Lower unit noise or water intrusion: inspect seals, bearings, gears, shafts, bearing carriers, and gear lube condition.
- Trim or steering problems: inspect trim motors, pumps, hydraulic components, steering cylinders, hoses, and related rigging parts.
Why Buy Mercury Outboard Parts from Pro Marine USA?
- OEM Mercury and aftermarket replacement options for many common applications.
- Parts for maintenance, repair, engine rebuilding, lower units, electrical systems, fuel systems, steering, trim, and rigging.
- OEM diagram and part-number lookup tools to help identify the correct part before ordering.
- Dealer pricing available for qualified marine repair businesses and dealers.
- Large inventory of Mercury service parts and hard-to-find marine engine components.
- Fast weekday shipping on qualifying in-stock orders.
Frequently Asked Questions
How do I find the correct Mercury outboard part?
Use the engine horsepower, model, serial number, and year whenever available. Mercury frequently uses serial-number ranges to identify engine families, so the serial number is often the most reliable way to confirm fitment.
Can I search Mercury parts by OEM part number?
Yes. Enter the Mercury OEM part number into the Pro Marine site search to locate available OEM and aftermarket replacement options. If you do not know the part number, use the OEM parts lookup first.
Do Mercury outboard parts vary by serial number?
Yes. Many Mercury components change by serial-number range even within the same horsepower or model family. Always compare the serial range listed for the part with your engine before ordering.
Do you carry parts for Mercury Optimax and Verado engines?
Yes. Pro Marine carries parts for many Mercury Optimax, Verado, Pro XS, EFI, FourStroke, and SeaPro applications, including maintenance, fuel, electrical, cooling, internal engine, lower unit, steering, and rigging components.
Do you carry both OEM and aftermarket Mercury parts?
Yes. Pro Marine offers genuine Mercury parts along with aftermarket replacement parts for many common Mercury outboard maintenance, repair, and rebuild applications.
What Mercury outboard parts are commonly replaced during routine maintenance?
Common maintenance items include engine oil, oil filters, fuel filters, spark plugs, water pump kits, impellers, thermostats, gear lube, drain plug seals, anodes, and manufacturer-specific service kit components.
Fitment Tip: Mercury outboard parts often vary by serial-number range. Confirm your engine serial number and OEM part number whenever possible before ordering.
40640
9024
8M0047624
8M0240950
8558432
883306
194-5279
8M0084173
815279T
8152793
8152795
830179T
8301792
854515
854515T1
856748
883072T
8M0236271
842739T02
842739T04
842739T05
842739T08
842739T12
842739T06
842739T07
842739T14
842739T15
194-8825K1
88825A1
88825A7
Sierra Replacement Mercury Outboard Control Module
Mercury V135, V140, V150, V200, XR-6 & 140 Jet Control Module - Sierra 18-99253
The Sierra 18-99253 Control Module is an aftermarket replacement for select Mercury outboard engines using Mercury 857185T1 and related control module applications.
Verified fitment includes select V-135, V-140, V-150, V-200, XR-6 / Magnum III and 140 Jet Mercury outboards.
The original Mercury OEM version of this module is no longer available. Sierra 18-99253 is the available replacement option for these applications.
Mercury has discontinued the original OEM control module used in these applications.
The Sierra 18-99253 is the available replacement for compatible engines that originally used Mercury 857185T1.
OEM & Cross Reference Numbers
| Brand / Type | Part Number |
|---|---|
| Sierra | 18-99253 |
| Cross Reference | 144-7185 |
| Mercury OEM | 857185T1 |
Mercury Outboard Fitment
| Mercury Engine | Serial Number Range |
|---|---|
| V-135 | 0G960500 thru 0T178499 |
| 140 Jet | 0G960500 thru 0T178499 |
| V-140 International | 0T178500 thru 1B226999 |
| V-150 | 0G960500 thru 1B226999 |
| XR-6 / Magnum III | 0G960500 thru 1B226999 |
| V-200 | 0G960500 thru 1B226999 |
Mercury used different electrical components across similar horsepower ranges. Do not order this control module by horsepower alone.
Verify the complete engine serial number and confirm the original module cross references 857185T1 or 144-7185 before ordering.
What This Control Module Does
The control module is part of the engine's electronic control system and helps manage the electrical functions assigned to the module within the Mercury outboard ignition / engine management system.
A failed control module can result in ignition or engine-running issues depending on the exact engine configuration and failure mode.
Common Reasons for Replacement
- Original Mercury module has failed
- Intermittent ignition or engine electrical problem
- Module has visible heat or electrical damage
- Diagnostic testing identifies the module as faulty
- Original Mercury 857185T1 is no longer available
Before Replacing the Module
Electronic control modules should not be replaced solely based on symptoms. Verify related wiring, grounds, connectors, stator / trigger components, charging voltage and other ignition-system components as applicable to the engine.
Follow Mercury service procedures for the exact engine and serial number before condemning the module.
Why Use Sierra 18-99253?
- Sierra aftermarket replacement control module
- Replaces discontinued Mercury OEM 857185T1
- Cross references 144-7185
- Fits select Mercury V-135 outboards
- Fits select Mercury V-140 International outboards
- Fits select Mercury V-150 outboards
- Fits select Mercury V-200 outboards
- Fits select Mercury XR-6 / Magnum III engines
- Fits select Mercury 140 Jet applications
- Available replacement now that the OEM module is discontinued
FAQ
Is Sierra 18-99253 an OEM Mercury part?
No. This is a Sierra aftermarket replacement.
What Mercury part number does 18-99253 replace?
It replaces Mercury 857185T1 and cross references
144-7185.
Is the original Mercury control module still available?
No. The Mercury OEM version is no longer available.
Sierra 18-99253 is the available replacement for compatible applications.
Does it fit Mercury V-150?
Yes. Verified fitment includes V-150 engines from
0G960500 thru 1B226999.
Does it fit Mercury XR-6?
Yes. Verified XR-6 / Magnum III fitment includes serial
0G960500 thru 1B226999.
Does it fit Mercury V-200?
Yes. Verified V-200 applications include serial
0G960500 thru 1B226999.
Does it fit Mercury V-135?
Yes. Verified V-135 fitment is
0G960500 thru 0T178499.
Does it fit a Mercury 140 Jet?
Yes. Verified 140 Jet applications are
0G960500 thru 0T178499.
Should I verify my serial number before ordering?
Yes. Mercury used different electrical components across similar engine
families, so the serial number should always be verified.
Dealer Discounts & Store Policies
Dealer / Marine Industry Discounts
Are you a marine dealer, technician, boat builder, or industry professional? We offer dealer pricing for qualified marine businesses.
Shipping Policy
- Free shipping on orders over $100 continental U.S.
- Orders received before 5:30 PM EST ship the same business day.
- Typical delivery time is 1-5 business days.
30-Day Return Policy
- Returns accepted within 30 days of delivery.
- Parts must be new, unused, and in original packaging.
- Installed electrical parts are not returnable.
- Return authorization is required before sending items back.
Need help verifying fitment?
Contact Pro Marine
Phone: 941-721-3000
Searchable Terms
18-99253, Sierra 18-99253, 144-7185, 857185T1, Mercury 857185T1, Mercury control module, Mercury ignition control module, Mercury V135 control module, Mercury V140 control module, Mercury V150 control module, Mercury V200 control module, Mercury XR6 control module, Mercury XR-6 module, Mercury Magnum III module, Mercury 140 Jet control module, discontinued Mercury control module, Mercury 857185 replacement, Sierra Mercury control module, 0G960500, 0T178499, 0T178500, 1B226999
857185T1