Yamaha LF350 UCB 350 HP V8 Outboard — New Old Stock, 30-Inch Shaft

About this engine

Before horsepower wars moved to superchargers and V10s, Yamaha's 5.3-liter V8 was the flagship — the engine that proved a four-stroke could out-muscle the big two-strokes offshore. These LF350 UCB engines are that motor: 5,330cc of DOHC 32-valve V8 with Variable Camshaft Timing, sequential fuel injection and the kind of displacement-driven torque that no boost gauge can imitate. We are listing them exactly as they are: new old stock. Earlier-generation units that were never sold, not current-model engines — and priced like it.

The LF in the model code matters: this is the counter-rotating version on a 30-inch shaft, built to pair with a standard-rotation F350 on twin-engine offshore hulls, canceling prop torque and keeping big center consoles tracking straight. Command Link digital electronic controls, a 1.73:1 gearcase and a 50-amp alternator complete a package that was Yamaha's offshore flagship specification.

Why does new old stock make sense? Because plenty of boats were designed, propped and rigged around this exact platform, and because a never-sold V8 at this money buys displacement and simplicity that newer engines charge a large premium for. We have 20 units in stock, photographed from the powerhead to the gearcase so you can see precisely what 'new old stock' looks like — an engine that has waited in storage, not one that has worked for a living.

A practical note for pair-builders: because this is the counter-rotation LF model on the 30-inch shaft, it is the harder half of a twin set to source — standard-rotation F350s turn up far more often. If your boat already runs a standard F350 and you have been waiting for its left-hand mate, or your repower plan starts with the counter engine and sources the standard second, this stock of 20 identical units removes the usual months of hunting.

Ownership of the 5.3 V8 is old-school in the best way: big displacement, naturally aspirated, Command Link digital instrumentation if you want it, and a service knowledge base built over a long production run. It asks for premium fuel (89 octane minimum) and gives back the deep, unstressed thrust that only 5.3 liters makes.

If you are completing a matched pair, repowering a hull that was built for this V8, or you simply want flagship displacement at a fraction of flagship money — 22.5% below our researched NOS market value — talk to us on WhatsApp.

Good to know

New old stock: earlier-generation Yamaha V8 units that were never sold — not the current-model F350. Listed honestly as new old stock.