MERCURY 5 HP 5MLHA-LPG SAIL POWER PROPANE OUTBOARD MOTOR

Description

The Mercury 5 HP 5MLHA-LPG Sail Power propane outboard motor brings together everything a small sailboat owner usually wishes their outboard had. It runs on propane so the fuel never goes stale. It has a 20 inch long shaft, a high thrust prop that actually moves a heavy hull, a charging system for your battery and a proper reverse gear. We have it for sale new, with the Mercury factory warranty, and we ship worldwide.

This is quite a specific motor, and that’s the point. If you sail a small keelboat or trailer sailer, motor only now and then, and already carry propane for the stove, it could be the best auxiliary you’ll ever own. Here’s why, and where it might not suit you.

On this page:

• Why this combination works for sailors
• Running on propane
• Sail Power: thrust and charging
• Boats it suits
• On the water
• Features
• Specifications
• Maintenance and gas safety
• Alternatives
• Price and shipping
• FAQ

Why this combination works so well for sailors

Think about how a sailboat outboard is actually used. Ten minutes out of the marina. Sails up, motor off. Maybe it sits for the rest of the day, maybe the rest of the week. Then ten minutes back in, often into a breeze, into a tight berth, with people watching. It needs to start first time after sitting, push a heavy hull with authority, stop the boat in reverse, and ideally keep a battery charged.

A standard small gasoline outboard struggles with most of that. The fuel goes stale in the carb. The prop is pitched for light, fast boats, so it slips on a heavy one. And unless you add a kit, it doesn’t charge anything.

The Mercury 5 HP 5MLHA-LPG Sail Power propane outboard motor answers each of those problems directly. Propane for reliable starting after long breaks. A 6 inch pitch high thrust prop for push and stopping power. A 12 volt, 50 watt charging system. And a 20 inch long shaft to keep the prop in the water when the stern rises on a wave.

The model code breaks down as 5 horsepower, M manual start, L long shaft, H tiller, A alternator, and LPG for propane.

Running on propane

There’s no carburetor full of gasoline and no built in fuel tank. Instead the motor has a propane regulator and a supply line that connects to an external cylinder. Propane doesn’t break down or leave varnish like gasoline, so you can leave the motor for weeks or months, reconnect the gas and start it.

Many sailboats already have propane on board for cooking. Crews are used to handling it, checking connections and storing cylinders safely in a vented locker. Switching the outboard to propane means you can take gasoline off the boat entirely. No jerry cans in lockers, no fuel smell, no drips on deck.

Propane cylinders are available in most countries, though sizes and fittings differ. We don’t ship a cylinder with the motor, but we’ll help you choose the right one and the right adapter for where you sail.

Sail Power: thrust and charging

The high thrust propeller is the other half of this motor’s appeal. It’s a low pitch prop designed to grip the water at displacement speeds. On a sailboat, that means stronger acceleration from a standstill, more push into a headwind or chop, and much more stopping power in reverse. The Mercury 5 HP 5MLHA-LPG Sail Power propane outboard motor will reach hull speed with less strain than a standard prop motor, because the prop isn’t slipping.

Then there’s the charging. The built in alternator gives up to around 4 amps, 50 watts, to keep a small house battery topped up for lights, a VHF and a depth sounder. Combine it with a small solar panel and many small boats are fully covered.

Boats the Mercury 5 HP 5MLHA-LPG Sail Power propane outboard motor suits

Measure from the top of your transom or bracket to the bottom of the hull. Around 20 inches means this long shaft motor is right. Around 25 inches means extra long, so look at the 5MXLHA-LPG Sail Power instead.

• Small keelboats and day sailers on an outboard bracket
• Trailer sailers, including heavier cabin models
• Small cruising sailboats used in sheltered and coastal waters
• Heavy displacement workboats and drift boats
• Boats that sit for long periods between uses

It’s less suited to light, fast boats like inflatables and planing skiffs. For those, a standard pitch motor like the 5MH-LPG will be quicker.

On the water

Starting

Connect the supply line, open the cylinder valve, put the motor in neutral, clip on the lanyard and pull. With propane there’s no carb to flood, so starting is usually easy even after a long break.

Shifting

Forward, neutral and reverse with a front mounted lever. Combined with the high thrust prop, reverse gives you real control in a marina.

Steering and throttle

Adjustable steering tension lets you lock the motor straight and steer with the rudder. Twist grip throttle with friction control.

Exhaust

Through the prop hub, so it’s quiet and the fumes stay underwater. Propane burns cleanly, so there’s little smell in the cockpit.

Shallow water drive

Six trim positions and a shallow water setting for creeping into thin water.

RPM

Full throttle is 4,500 to 5,500 rpm.

Mercury 5 HP 5MLHA-LPG Sail Power propane outboard motor features

• Runs on propane (LPG) from an external cylinder
• 6 inch pitch high thrust propeller
• 4 amp, 50 watt charging system
• 20 inch long shaft
• Digital CD ignition with spark advance
• High grade marine alloy construction
• Stainless steel water pump housing
• Zinc coated water passages
• Rated for saltwater use
• Sacrificial zinc anodes
• Forward, neutral and reverse gear shift
• Forward mounted gear shift selector
• Adjustable steering tension control
• Twist grip throttle with tension control
• Integrated carry handle
• Thermostat controlled water cooling
• Shallow water drive with 6 trim positions
• Quiet through propeller hub exhaust
• Start in gear protection
• Low oil pressure warning indicator
• ESG over rev protection
• Safety lanyard stop switch
• Owner’s manual
• Mercury Marine 3 year warranty

Mercury 5 HP 5MLHA-LPG Sail Power propane outboard motor specifications

For Mercury’s overview of their small outboards, see the FourStroke outboards page. We’re happy to confirm any detail for the exact unit you buy.

Maintenance and gas safety

Propane

Inspect the hose and fittings before every use. Keep the connector clean. Close the cylinder valve when you finish. Store cylinders upright and secured, in a vented locker that drains overboard, never below decks.

Engine oil

About 450 ml of 10W-30. Check before each outing. First change at 20 hours, then every 100 hours or yearly.

Gear case

Change gear lube yearly. Milky lube means water is getting in.

Cooling and salt

Check the telltale on every start. Rinse the Mercury 5 HP 5MLHA-LPG Sail Power propane outboard motor with fresh water when you can and check the anodes each season.

The US Coast Guard boating safety site has clear guidance on fuel handling and safe boating that applies wherever you sail.

Common questions about the Mercury 5 HP 5MLHA-LPG Sail Power propane outboard motor

Is the Mercury 5 HP 5MLHA-LPG Sail Power propane outboard motor as strong as the gasoline version?

In everyday use on a sailboat, you’d be hard pushed to tell the difference. It uses the same 123 cc powerhead and the same high thrust prop concept. What you’ll notice is how reliably it starts after sitting and how little it smells.

How long will a propane cylinder last with the Mercury 5 HP 5MLHA-LPG Sail Power propane outboard motor?

That depends on the cylinder size and how long you motor. If you only motor in and out of harbour, a modest refillable cylinder can last a long time. For long motoring passages, carry a larger cylinder or a spare. We’ll suggest a sensible size when you tell us how you sail.

Can I share the galley propane supply?

Most owners use a separate cylinder for the motor, kept in a vented locker near the stern. It keeps hose runs short and means one system doesn’t affect the other.

Is it heavier than the gasoline Sail Power?

They’re both around 58 pounds. The difference is that with propane you don’t carry fuel in the motor itself.

Will the charging system keep my battery full?

It’ll top up a small battery during normal motoring. For boats that motor very little, add a small solar panel as well. That pairing works very well with the Mercury 5 HP 5MLHA-LPG Sail Power propane outboard motor.

Installing the Mercury 5 HP 5MLHA-LPG Sail Power propane outboard motor

Lower the bracket, lift the motor on by the carry handle and centre it. Tighten both clamp screws firmly by hand and tie a safety line to a strong fitting. Raise and lower the bracket to check it clears the rudder and pushpit through its full range.

Mount the propane cylinder in a vented locker or a secure bracket where any leak can escape overboard. Route the supply line so it can’t chafe or snag on sheets and the tiller. Connect it with the correct adapter, open the valve slowly, and check for any smell of gas.

Run the charging lead to your battery with an inline fuse close to the battery, as the owner’s manual describes. Then check the oil, clip on the lanyard, put it in neutral and start. Look for the cooling telltale. Vary the throttle for the first couple of hours.

Storing the Mercury 5 HP 5MLHA-LPG Sail Power propane outboard motor

Here’s where propane really pays off. At the end of the season, close the cylinder valve and disconnect the supply. That’s the fuel system taken care of. Then flush the cooling system, change the oil and gear lube, grease the swivel and clamp screws, and store the motor upright or on its correct side in a dry place. Keep the cylinder outside or in a well ventilated space. Next spring, reconnect and it’s ready.

Why sailors pick the Mercury 5 HP 5MLHA-LPG Sail Power propane outboard motor

When we ask buyers why they chose this particular motor, the answers tend to fall into four groups.

They were fed up with stale fuel. A sailboat outboard can go weeks between runs. With gasoline that often means a gummed up carb and a motor that won’t start just when you need it. The Mercury 5 HP 5MLHA-LPG Sail Power propane outboard motor removes that problem completely.

They wanted gasoline off the boat. No more jerry cans in cockpit lockers, no more fuel smell, no more drips on deck when topping up at sea. If the galley already runs on propane, the whole boat now uses one fuel.

They needed real thrust. Owners of heavier small keelboats and trailer sailers find a standard pitch prop slips and screams. The high thrust prop bites properly, moves the boat with authority and stops it in reverse.

They wanted charging without extra kits. The built in alternator keeps a small battery topped up every time you motor.

Getting the best from it on a sailboat

Set the bracket so the anti ventilation plate sits a few inches under the water with the boat loaded. Use the tilt pin to get the motor running as close to vertical as you can. Once you reach the boat’s natural hull speed, back off the throttle, because more throttle only burns more propane without adding speed. Lock the steering straight and steer with the rudder once under way. Wear the kill cord at all times. And lift the motor clear when sailing so it doesn’t drag or collect weed.

Follow those simple habits and the Mercury 5 HP 5MLHA-LPG Sail Power propane outboard motor will be the least troublesome part of your boat.

Who it isn’t for

If your boat is a light inflatable or a planing skiff, the high thrust prop will hold you back and you’d be better served by the 5MH-LPG or a gasoline 5MH. If propane is hard to get where you sail, the gasoline 5MLHA Sail Power gives you the same sailboat setup with a built in fuel tank. And if your boat is heavy or you sail exposed coasts, consider more horsepower. We’re always happy to talk it through.

Spares to keep aboard

A spare spark plug and spanner, a shear pin or prop hardware, a spare lanyard, a small bottle of engine oil, a fuse for the charging lead and a spare seal for the propane connector. Keep them in a dry bag in a cockpit locker. It covers nearly every small problem you’re likely to face with the Mercury 5 HP 5MLHA-LPG Sail Power propane outboard motor away from the dock.

Is 5 hp enough for your boat?

For most small keelboats, day sailers and light to mid weight trailer sailers in sheltered and coastal waters, yes. The high thrust prop on the Mercury 5 HP 5MLHA-LPG Sail Power propane outboard motor makes 5 hp feel stronger on a sailboat than the number suggests, because far less of the engine’s effort is wasted in prop slip.

A simple test is to look at what similar boats in your marina or class association use. If most run 4 to 6 hp, you’re in the right range. If they’re running 8 or 9.9, your boat probably needs more.

Think too about where you sail. A sheltered lake or estuary asks much less of a motor than a coast with strong tides and short steep seas. On open water it’s worth having power in reserve.

If you’d like a second opinion, send us your boat’s make, model and length, and tell us where you sail. We’ll tell you honestly whether the Mercury 5 HP 5MLHA-LPG Sail Power propane outboard motor is the right match or whether another model would suit you better.

A few words on propane cylinders around the world

Propane is sold almost everywhere, but cylinder sizes and valve fittings vary by country. Some regions use small screw on camping cylinders, others use larger refillable bottles with a different valve type. That’s why the motor ships with its supply line but no cylinder. Once you tell us where you’ll be using it, we can point you to the right adapter so the Mercury 5 HP 5MLHA-LPG Sail Power propane outboard motor connects to the cylinders you can actually buy locally. If you cruise between countries, it’s worth carrying an adapter set so you can refill or swap cylinders wherever you end up.

Paperwork, warranty and keeping records

When your Mercury 5 HP 5MLHA-LPG Sail Power propane outboard motor arrives, write down the serial number and keep it with your invoice. Take a photo of the serial plate on your phone too. If you ever need warranty work, a dealer will ask for both, and it makes the process much quicker. The Mercury factory warranty starts from the date of purchase, so hang on to that paperwork.

It is also worth keeping a simple log: date, engine hours if you have them, oil changes, gear lube changes, impeller replacements and anything unusual you noticed. It takes seconds after each service, and it adds real value if you ever sell the boat. Buyers pay more for an engine with a clear service history, and it helps any mechanic you work with understand the motor quickly.

Check your boat insurance as well. Many policies have specific requirements for outboard security, such as a lock on the clamps or bracket, and some ask for the serial number. Better to sort that out on day one than find out after a problem.

Alternatives

5MLHA Sail Power: the same sailboat package on gasoline, with a built in tank.

5MLH-LPG: long shaft propane with a standard prop and no charging.

5MXLHA-LPG Sail Power: the extra long 25 inch shaft version.

6MLH: more power for bigger boats.

Browse the full range in our Mercury outboard motors category.

Mercury 5 HP 5MLHA-LPG Sail Power propane outboard motor for sale: price and shipping

The price of the Mercury 5 HP 5MLHA-LPG Sail Power propane outboard motor is at the top of this page. Buy it through the cart, or contact us for a delivered quote.

In the box

• Mercury 5 HP 5MLHA-LPG Sail Power propane outboard motor, new
• High thrust propeller, fitted
• LPG fuel supply line
• Owner’s manual
• Mercury Marine 3 year factory warranty from the date of purchase

A propane cylinder isn’t included. We’ll help you choose one that suits your country’s fittings.

Shipping

We ship worldwide by courier or freight, securely packed and tracked. We’ll explain import duty and taxes for your country before you pay if you ask.

Buying from us

Read our refund and return policy, see our customer reviews, and visit the about page.

FAQ

Does the Mercury 5 HP 5MLHA-LPG Sail Power propane outboard motor charge a battery?

Yes, up to 12V, 50W, 4A.

Is a propane cylinder included?

No. We’ll advise you on the right cylinder and adapter.

Does it have reverse?

Yes, forward, neutral and reverse.

What shaft length?

20 inches, long shaft.

How heavy?

About 58 pounds.

Do you ship worldwide?

Yes. Contact us for a delivered quote.

Order your Mercury 5 HP 5MLHA-LPG Sail Power propane outboard motor

Clean propane fuel, a prop that actually pushes a sailboat, charging and reverse, in a motor you can lift yourself. Add the Mercury 5 HP 5MLHA-LPG Sail Power propane outboard motor to your cart, or ask us a question. You can also browse all our outboard motors for sale.