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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.
Replacement Hydraulic Steering Cylinder
Pro Marine 350-HSTEER-CYL Hydraulic Steering Cylinder
The Pro Marine 350-HSTEER-CYL Hydraulic Steering Cylinder is the replacement steering cylinder used with the Pro Marine 350-HSTEER hydraulic steering system. It is designed for high-horsepower single outboard setups where smooth, controlled steering response is critical.
This is the cylinder only. Helm pump, hoses, steering fluid, and fill/bleed accessories are sold separately unless purchased as part of the complete 350-HSTEER system.
What This Cylinder Is Used For
The steering cylinder converts hydraulic pressure from the helm pump into side-to-side movement at the outboard engine. It is the component that physically moves the engine when you turn the steering wheel.
If your current cylinder is leaking, damaged, binding, or worn, replacing it can restore proper steering control and improve the overall feel of the system.
Read our 350-HSTEER Steering Comparison & Pro Tips Guide
Best Applications
| Application | Recommended Use |
|---|---|
| 350-HSTEER Systems | Replacement hydraulic steering cylinder |
| Single Outboards up to 350HP | High-horsepower hydraulic steering applications |
| Bass Boats | Responsive steering and control at speed |
| Bay Boats | Smooth steering in shallow and open water |
| Center Consoles | Reliable steering feel for offshore and coastal use |
Build or Service Your Steering System
Complete Steering Kit
Need the full system instead of just the cylinder? The complete kit includes the cylinder, helm pump, hydraulic fluid, and fill hose assembly.
View 350-HSTEER Complete KitHelm Pump
Pair this cylinder with the matching Pro Marine helm pump for proper hydraulic steering operation.
View 350-HELM-025 Helm PumpHydraulic Hoses
Select the correct hydraulic hose length for your boat, jack plate, setback, and rigging route.
Shop Pro Marine Hydraulic HosesFluid & Fill Hose
Hydraulic fluid and a fill hose assembly help make installation and bleeding easier during service.
View PRO-OIL15 Hydraulic FluidView 102P Fill Hose Assembly
Complete Your Steering Setup
Need additional Pro Marine steering components?
Key Features and Benefits
- Replacement hydraulic steering cylinder for 350-HSTEER systems
- Designed for high-horsepower single outboard steering applications
- Helps restore smooth steering movement and control
- Front-mount hydraulic steering cylinder design
- Works with hydraulic helm, hose, and fluid circuit
- Good option for service, repair, or steering system rebuilds
System Function and Connections
- System Type: Hydraulic outboard steering
- Component Type: Steering cylinder
- Connection Type: Hydraulic hose connections to helm circuit
- Typical Use: Single outboard applications up to 350HP when used with the proper system
- Related Components: Helm pump, hydraulic hoses, steering fluid, fittings, and fill/bleed tools
FAQ
Is this the complete steering system?
No. This listing is for the hydraulic steering cylinder only. The complete
system is available as the Pro Marine 350-HSTEER kit.
What system does this cylinder work with?
This cylinder is designed for use with the Pro Marine 350-HSTEER hydraulic
steering system.
Are hydraulic hoses included?
No. Hydraulic hoses are sold separately so you can choose the correct length
for your boat and rigging layout.
When should I replace a steering cylinder?
Replace the cylinder if it is leaking, damaged, binding, corroded, or no
longer holding proper steering control.
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 ship via UPS, USPS, and FedEx.
- 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.
- Items must be new, unused, and in original packaging.
- Return authorization is required before sending items back.
Need help with a return or order question?
Contact Us
Phone: 941-721-3000
Searchable Terms
350-HSTEER-CYL, Pro Marine hydraulic steering cylinder, hydraulic steering cylinder, outboard steering cylinder, front mount steering cylinder, 350-HSTEER replacement cylinder, hydraulic steering repair, boat steering cylinder
