Mercury 115 HP ProXS Electric Start Steering Trim Tilt CT Extra Long Shaft Outboard Motor

The Mercury FourStroke 115 XL CT ProXS is a 4-stroke outboard marine engine designed for sport fishing boats requiring an extra-long shaft, speed-focused fiberglass boats, and performance-oriented users. It features a 115 HP / 86 kW and 2064 cc 4-cylinder engine. Thanks to its Command Thrust (CT) gearcase system, it has the large gearcase and propeller of a higher horsepower engine. The ProXS series is Mercury's line offering optimized high-performance configurations compared to standard FourStroke engines. It is developed for boat use prioritizing speed and responsiveness, with a high RPM range and performance-oriented fine-tuning.

FourStroke 115 XL CT ProXS Series Features and Technology Advantages

ProXS models operate at a higher RPM range compared to their standard FourStroke counterparts. Performance-oriented ECU calibration shifts the power band to higher RPMs, increasing responsiveness and top speed.

• 4-Cylinder Engine (2064 cc): ProXS models operate at a higher RPM range compared to their standard FourStroke counterparts.
• Extra Long Shaft (572 mm (22.5")): The propeller operates at an optimal depth for the correct transom height.
• ProXS Performance Configuration: Enhanced responsiveness and top speed with a high RPM range and optimized ECU calibration.
• Command Thrust (CT) Gearcase: The large gearcase and propeller of a higher horsepower engine — high torque at low RPMs and powerful thrust capability.
• Electric Start: Instant activation with a key or button — comfortable and fast starting.
• Power Trim & Tilt: Adjust trim angle with a button while cruising — optimizes fuel efficiency; fully lift the engine with tilt.
• Floating External Fuel System: Connection for a large-capacity external tank — range determined by user need.

Extra Long Shaft — What Type of Boat Is It Suitable For?

The extra-long shaft (572 mm (22.5")) ensures the propeller operates at the correct water depth on large, high-sided fiberglass and aluminum boats. It is 64 mm longer than the standard long shaft (508 mm).

Technical Specifications

Who Is This Engine For?

• Sport fishing boat: fast planing and quick positioning with a high RPM range.
• Performance-oriented fiberglass boat: increased responsiveness and speed with ProXS calibration.
• Tournament fishing: fast relocation and efficient fuel usage.
• Boat owners seeking speed and performance: a superior performance layer compared to standard FourStroke.

Maintenance and Longevity

Mercury 4-stroke engines operate trouble-free for many years with regular oil changes and end-of-season maintenance protocols. The impeller of the water-cooled system should be checked every 100 hours or every two seasons. In saltwater use, freshwater flushing is mandatory after each use.

Related maintenance categories: Maintenance Kit | Engine Oil | Impeller | Mercury Spare Parts

Frequently Asked Questions

What is the difference between ProXS and standard FourStroke 115 HP?

ProXS models offer the same engine block with a higher RPM range and performance-oriented ECU calibration. Compared to the standard model, it provides a higher maximum RPM, increased responsiveness, and superior top speed performance. Fuel consumption might be slightly higher at wide open throttle positions.

Which propeller works best with the ProXS engine?

Since ProXS models are optimized for a high RPM range, a propeller with less pitch is generally preferred. Propeller selection should be determined by a Mercury service technician based on boat type, weight, and desired speed-acceleration balance.

Are ProXS maintenance requirements different from standard FourStroke?

Basic maintenance requirements are similar: regular oil changes, impeller checks, and end-of-season maintenance. However, due to high RPM usage, more attention to oil quality is recommended. Service intervals should be followed according to manufacturer recommendations.

Which boat and vessel brands are compatible with the FourStroke 115 XL CT ProXS?

Mercury outboards are compatible with many fiberglass, aluminum, and inflatable boat models thanks to their universal transom clamp or transom mounting system. The only criteria are your boat's 572 mm (22.5") transom height and the maximum engine power approved by the manufacturer. You can get compatibility confirmation from Clever Marin by sharing your boat model.

Related Products and Categories

• Mercury Outboard Motors
• Mercury Marine Products
• Mercury Spare Parts
• Mercury ProXS 115–150 HP
• Mercury 175–300 HP FourStroke
• Outboard Motors
• Boat Engines
• Maintenance Kit
• Impeller
• Anode

Is It the Right Configuration for Your Boat?

Share your boat model, transom height, and intended use — let's confirm together the suitability of the Mercury FourStroke 115 XL CT ProXS engine for your boat and the correct shaft selection.