Yamaha LF350XSA2 350HP 25″ Counter-Rotation Outboard

Description

The Yamaha LF350XSA2 pairs 350HP with a 25-inch shaft, built with counter-rotation gearing for multi-engine offshore boats. The 4.3-liter 60-degree V6 displaces 4256cc and weighs 629 lbs dry. Built for mid-transom configurations, the 25-inch shaft keeps propeller depth and tracking balanced on heavy-duty fiberglass hulls in rough open water.

Peak output holds through a 5000-6000 RPM band, sustaining cruising speed across long tournament distances. The 1.75:1 gear ratio converts combustion force into a flat torque curve, so heavy boats get on plane without burying the stern under load. This is a Japan-built platform, engineered for stability during long-range offshore operations.

Technical Specifications of Yamaha LF350XSA2

• Electronic fuel injection uses an 81mm throttle valve for strong volumetric efficiency across all cylinders.
• A 70-Amp fan-cooled stator alternator generates enough power to keep house battery banks topped off.
• Integrated electric steering replaces complex hydraulic lines with instant digital response at the wheel.
• TotalTilt simplifies trailering and shallow-water operation by tilting the lower unit completely clear.
• A 7.9-liter oil sump supports continuous lubrication during hard wide-open-throttle runs.
• The counter-rotation gearcase balances propeller torque to maintain tracking on multi-engine express cruisers.

Variable Camshaft Timing

Variable camshaft timing adjusts the intake valves on this 24-valve DOHC V6 to improve thermal efficiency, reducing response lag and improving torque delivery under offshore load.

Air Induction Throttle Control

An 81mm throttle valve regulates a large volume of clean air into the intake track for complete combustion on 89-octane fuel. That delivery method keeps throttle response immediate and cold starts reliable in changing early-morning coastal conditions.

Counter Rotating Propeller Gearcase

Oversized internal gears and a streamlined lower unit maximize hydrodynamic thrust while canceling out steering pull on multi-engine setups. That mechanical setup keeps lower-unit chatter down and propeller tracking steady when backing down on a fish.

Digital Power Management Setup

Digital electronic control integrates with the electric steering system to handle house power needs automatically, coordinating with the stator cooling loop to run multifunction displays and gyro stabilizers without draining the batteries.

Advanced Fiberglass Hull Application

High-performance bay boats, multi-engine offshore center consoles, and sportfishing platforms in the 24-35 ft range are the target application for this 25-inch outboard. The mid-length shaft delivers strong leverage and vibration dampening driving through steep waves.

Cowling Access And Lubrication

A multi-piece outer cowling gives fast access to critical checking points, cutting service time down. The drain plug location keeps oil changes clean rather than messy. Pro Tip from the Shop: pull the gear lube plugs at the dock and use a lower unit pump to push fresh oil from the bottom up, keeping air pockets out of the gear housing.