Mercury 25 HP 2-Stroke Rope Start Long Shaft Outboard Motor

The Mercury 25 ML SeaPro 2-Stroke - Solas is an outboard marine engine designed for boats and dinghies requiring a long shaft, featuring a 25 HP / 18.6 kW and 430 cc 2-cylinder engine. Its 2-stroke design offers a higher power-to-weight ratio compared to 4-stroke alternatives. The Solas branded propeller configuration comes as a factory standard.

25 ML SeaPro 2-Stroke Engine Features

A 2-stroke engine produces higher power density compared to 4-stroke alternatives of the same cc displacement. The 430 cc 2-cylinder design offers a compact and portable power source with a lightweight of 51 kg. It requires an oil-gasoline mixture; the maintenance routine differs from 4-stroke engines.

• 2-Cylinder 2-Stroke Engine (430 cc): High power density — more powerful output compared to a 4-stroke of the same displacement.
• Long Shaft (508 mm / 20"): Compatible with boats and inflatable dinghies with standard transom height.
• Solas Propeller Configuration: Factory-standard optimized propeller choice.
• Manual Start: Battery-independent reliable mechanical starting.
• Manual Trim: Manual adjustment of transom angle — simple and reliable mechanical structure.
• 25-Liter Internal Tank: Sufficient capacity for mid-range routes.

Long Shaft — Suitable for Which Boat Type?

A long shaft (508 mm / 20") is suitable for the vast majority of inflatable dinghies, aluminum boats, and fiberglass boat models. For boats with a transom height of 381 mm, a short shaft model should be preferred.

Technical Specifications

Who is This Engine For?

• Commercial fishing and heavy use: Compact and lightweight solution with 2-stroke power density.
• Cost-oriented preference: Lower initial acquisition cost advantage of the 2-stroke design.
• Solas propeller combination: Ready for immediate use with a factory-optimized propeller.
• Light boat and inflatable dinghy users: Easy installation and transport with a portable weight of 51 kg.

Maintenance and Longevity

2-stroke engines require an oil-gasoline mixture. Adhering to the manufacturer's specified mixing ratio is essential. For saltwater use, freshwater rinsing is recommended after each use.

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

Frequently Asked Questions

What advantage does a 2-stroke Mercury engine offer over a 4-stroke?

A 2-stroke engine produces higher power output compared to a 4-stroke of the same cc displacement — it has a higher power-to-weight ratio. Its simpler mechanical structure can result in lower maintenance costs. It requires a fuel+oil mixture; it does not have the advantage of separate oil reservoirs like 4-stroke engines.

What does Solas propeller configuration mean?

Solas is a high-performance propeller manufacturer. In this model, a Solas branded propeller comes as a factory configuration. The propeller pitch and design are optimized according to the engine's power characteristics. For spare propeller supply, you can get support from Clever Marin.

How is the 25 ML SeaPro 2-Stroke maintained?

2-stroke Mercury engines require a fuel mixture with special 2T marine engine oil. The mixing ratio specified by the manufacturer must be strictly adhered to. Gear oil and spark plug replacement are part of regular maintenance. If not to be used for a long time, it is recommended to drain the fuel system.

Which boat and dinghy brands are compatible with the 25 ML SeaPro?

Mercury outboard engines are compatible with many inflatable dinghy and aluminum boat models thanks to their universal transom clamp system. The only criteria are your boat's 508 mm (20") transom height and the manufacturer-approved maximum engine power. You can share your boat model to get compatibility confirmation from Clever Marin.

Related Products and Categories

• Mercury Outboard Engines
• Mercury Marine Products
• Mercury Spare Parts
• Mercury 2.5–30 HP FourStroke
• Outboard Engines
• Boat Engines
• Maintenance Kit
• Engine Oil
• Anode

Is This the Right Configuration for Your Boat?

Share your boat model, transom height, and intended use — let's verify together if the Mercury 25 ML SeaPro 2-Stroke engine is suitable for your boat.