MERCURY 40HP 40MLHGA OUTBOARD MOTOR

Description

The Mercury 40 HP 40MLHGA outboard motor is a manual start, tiller steer 40 hp four stroke with a 20 inch long shaft and gas assisted tilt. It uses Mercury’s three cylinder, 45.6 cubic inch (747 cc) engine and weighs a little over 200 pounds. It’s one of the simplest ways to put 40 horsepower on a tiller boat, with no starter, no charging system and no battery needed. We have it for sale new with the Mercury factory warranty and ship worldwide.

For owners who work far from help, or who simply want as little as possible to go wrong, the Mercury 40 HP 40MLHGA outboard motor is about as straightforward as a 40 gets.

On this page:

• Why the Mercury 40 HP 40MLHGA outboard motor
• Boats it suits
• Features
• Specifications
• Maintenance
• Alternatives
• Price and shipping
• FAQ

Why the Mercury 40 HP 40MLHGA outboard motor

Forty horsepower opens up bigger boats and bigger loads. On a 16 to 17 foot aluminum boat, it planes quickly with three people and gear, holds speed into a chop and cruises without strain. The three cylinder, 747 cc engine has a long stroke that delivers strong low end torque, so acceleration is brisk even with a full boat.

Manual start keeps the whole package simple and robust. That appeals to commercial users in remote places, to people who keep their boat somewhere without charging, and to anyone who has been let down by a flat battery before. Gas assisted tilt helps you raise the motor by hand without straining.

Model code: 40 hp, M manual start, H tiller, L means a 20 inch long shaft, GA gas assist tilt. This listing shows carbureted fuel induction; many current 40s are EFI, so ask us which version is in stock.

Boats the Mercury 40 HP 40MLHGA outboard motor suits

• Aluminum tiller boats of 16 to 17 feet with a standard 20 inch transom
• Work skiffs and utility boats
• Fishing boats in remote areas
• RIBs rated for 40 hp

Check that your transom suits a 20 inch shaft and your boat is rated for 40 hp.

On the water

Clip on the lanyard, put it in neutral and give it a firm pull. The three cylinder settles into a steady idle. Shift and steer from the tiller, open the throttle and the boat climbs onto plane cleanly. Use the gas assist to tilt up for shallows or trailering.

Buyer questions

“Is a 40 hard to pull start?”

It takes a firm, confident pull. Most adults manage it fine. If that’s a concern, choose an electric start model such as the 40ELHGA.

“Can it charge a battery?”

Not this version. The electric start 40s have an 18 amp alternator.

Mercury 40 HP 40MLHGA outboard motor features

• Three cylinder, 45.6 cu in (747 cc) four stroke
• Long stroke design for low end torque
• Manual start, no battery needed
• Tiller steering
• Gas assisted tilt
• Forward, neutral and reverse
• 20 inch long shaft
• Phantom Black finish
• Mercury Marine factory warranty

Mercury 40 HP 40MLHGA outboard motor specifications

For the manufacturer’s own overview of the range, see Mercury’s FourStroke outboards page. Mercury updates details between model years, so if one spec really matters to your purchase, ask us and we’ll confirm it on the exact unit we ship.

Maintaining the Mercury 40 HP 40MLHGA outboard motor

Fuel: fresh 87 octane, up to 10% ethanol.

Oil: Mercury four stroke oil, checked before each trip and changed on schedule.

Gear case: change the lube yearly.

Cooling: check the telltale every start; flush after saltwater use.

If you’re newer to boating, the US Coast Guard boating safety site is worth a read. It’s written for US boaters, but the advice on kill cords, life jackets, fuel handling and navigation rules applies wherever you are in the world.

Getting the propeller right

The propeller is the part of your Mercury 40 HP 40MLHGA outboard motor that actually turns engine power into movement, and the right one makes a big difference. The goal is simple: with your boat loaded the way you normally use it, the engine should reach the top of its recommended full throttle rpm range. If it can’t get there, the prop pitch is too high and the engine is labouring. If it goes past the top of the range, the pitch is too low and the engine is over revving.

As a rough guide, each inch of pitch changes full throttle rpm by around 150 to 200 rpm. Heavier loads and bigger boats usually want less pitch. Lighter, faster boats can take more. If you mainly carry heavy loads or tow, a lower pitch prop helps. If you run light and want top speed, a higher pitch may suit. Tell us about your boat and how you use it, and we’ll help you choose.

Trailering with your motor

Most owners of a motor like the Mercury 40 HP 40MLHGA outboard motor leave it on the boat and trailer them together. A few habits protect the motor on the road. Use a transom saver or motor support bracket where recommended, so the motor isn’t bouncing on its tilt mechanism over bumps. Make sure there’s good ground clearance under the skeg. Close the fuel vent and disconnect the fuel line. And check the motor mounting bolts or clamps before every trip, because vibration on the road can loosen them over time.

At the ramp, lower the motor only once there’s enough water under it, and raise it before you drive the boat onto the trailer. It sounds obvious, but a surprising number of skegs and props get damaged at the ramp rather than out on the water.

Using your motor through the seasons

In spring, check the oil, fit fresh fuel, look over the fuel line and connectors for cracks, and run the engine on a flushing attachment or in a test tank before the first real trip. Look for a strong cooling stream and a smooth idle.

Through summer, the main jobs are fresh fuel, regular oil checks and rinsing after saltwater use. Keep an eye on the propeller for dings. A damaged prop costs you speed and fuel, and can cause vibration.

In autumn, before the boat is laid up, do the full storage routine: flush, change the oil and gear lube, deal with the fuel system as the owner’s manual describes, grease the moving parts and store the Mercury 40 HP 40MLHGA outboard motor somewhere dry. Twenty minutes in autumn saves hours of frustration in spring.

Paperwork, warranty and keeping records

When your Mercury 40 HP 40MLHGA 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.

Why buy from us

We deal in outboard motors every day, and we would rather give you a straight answer than make a quick sale. If you are not sure the Mercury 40 HP 40MLHGA outboard motor is the right motor for your boat, message us with the make, model and length of the boat, how you use it and where you boat. We will tell you honestly whether it is a good match or whether something else would suit you better.

Every motor is packed carefully for the journey, and we keep you updated from dispatch to delivery with tracking. We ship worldwide, and we are happy to explain in advance what to expect with import duties and local taxes in your country, so there are no surprises when it arrives.

After you buy, we are still here. If you have questions about setup, break in or maintenance, just ask.

A small spares kit worth carrying

You do not need a workshop on board, but a few cheap parts turn most breakdowns into a ten minute fix. For the Mercury 40 HP 40MLHGA outboard motor, we suggest a spare spark plug and the right spanner, spare propeller hardware, a spare kill cord, a small bottle of engine oil, a couple of fuses if the motor has electrics, and a fuel line O ring or connector seal. Add some cable ties, a roll of self amalgamating tape and a basic multi tool.

Pack it all in a small dry bag, keep it in the boat, and check it every spring. Most owners never need it. The ones who do are very glad it was there.

A quick checklist before every trip

It sounds obvious, but most days that go wrong on the water start with something small that got missed at the dock. Before you head out with your Mercury 40 HP 40MLHGA outboard motor, run through this in your head:

• Enough fresh fuel for the trip, plus a sensible margin
• Engine oil checked and at the right level
• Motor mounted securely and everything tight
• Kill cord clipped to you, not left on the tiller or dash
• Cooling telltale spraying water once the engine is running
• Life jackets, a way to call for help, and a small spares kit aboard

It takes a minute or two. It is also the habit that separates relaxed boat owners from the ones waiting for a tow.

More questions we get asked

Can I install the Mercury 40 HP 40MLHGA outboard motor myself?

Many owners do, following the owner’s manual. If you are not confident with mounting, rigging or electrics, a local marine mechanic can set it up quickly, and it is money well spent.

How often does it need servicing?

Check the oil before every trip. Change the engine oil and gear lube at least once a year, or at the hour intervals in the owner’s manual, whichever comes first. Inspect the water pump impeller regularly and replace it as recommended.

What fuel should I use?

Fresh unleaded petrol of the octane rating shown in the specifications, with no more than 10% ethanol, unless it is a propane model. Old fuel is the cause of most running problems.

Can I pay in instalments?

Payment options vary by country. Contact us and we will tell you what is available for your order.

Why fuel care matters so much

If there’s one thing that decides whether an outboard starts first time or leaves you pulling and swearing at the ramp, it’s fuel. Modern petrol, especially with ethanol blended in, starts to break down within weeks. It absorbs moisture, separates and leaves gummy deposits that block the tiny passages in fuel systems.

For your Mercury 40 HP 40MLHGA outboard motor, the rules are simple. Buy fresh fuel from a busy station. Don’t store it for months in a can. Keep the tank vent closed when the boat isn’t in use. Use a fuel stabiliser if the boat will sit for more than a few weeks. And before any long lay up, deal with the fuel system as the owner’s manual describes, rather than leaving old fuel inside the engine. It’s a few minutes of effort that saves a lot of cost and frustration.

Your first run

The first hours of a new engine matter. For your Mercury 40 HP 40MLHGA outboard motor, follow the break in guidance in the owner’s manual. In broad terms: run at varied speeds, avoid long periods at full throttle, and don’t let it idle for ages either. Keep an eye on the cooling telltale and gauges, and listen for anything unusual.

After the break in period, change the engine oil and filter if fitted, and check the gear lube. From then on, just use it and service it on schedule. A well run in engine rewards you with smoother running and a longer life.

Real world setups for the Mercury 40 HP 40MLHGA outboard motor

A 16 foot aluminum work skiff at a remote fishing camp, carrying nets, fuel and two crew, is a textbook home for the Mercury 40 HP 40MLHGA outboard motor. With no electrics to fail, it keeps running season after season with basic care. On a 17 foot tiller fishing boat without electronics, it gives strong, simple power. And on a RIB rated for 40, it makes a quick, rugged runabout that doesn’t depend on a battery.

About Mercury’s 40 hp FourStroke engine

Most of Mercury’s recreational 40 hp FourStrokes, including the Mercury 40 HP 40MLHGA outboard motor, are built on a compact inline three cylinder engine of 747 cc (45.6 cubic inches), with a single overhead cam and two valves per cylinder. The bore is 65 mm and the stroke 75 mm, a long stroke design that favours torque low in the rev range. In practice, that means strong acceleration and the ability to push a loaded boat without having to rev the engine hard.

Mercury also made these engines easy to live with. They’re designed to be as close to maintenance free as practical, with a valve train that doesn’t need regular adjustment, an easy access oil filter, thermostatic cooling for steady running temperatures, and engine protection that warns of low oil pressure, over revving and overheating. Electric start models add an 18 amp, 226 watt alternator, which is plenty to keep a battery charged with a fish finder, lights and a livewell running.

New versus used: why buying new makes sense

We get asked this a lot. A used outboard can look like a bargain, but you rarely know its real history: how it was stored, whether it sat with stale fuel, whether it was flushed after saltwater, or whether it was run hard without oil changes. Problems like a worn water pump, a corroded cooling system or a damaged gearcase don’t always show up on a quick test.

A new Mercury 40 HP 40MLHGA outboard motor comes with a known history, which is none, and a full Mercury factory warranty that starts on the day you buy it. You get the latest version of the engine, fresh seals and gaskets, and years of trouble free running ahead with basic care. Over the life of the motor, that peace of mind is usually worth far more than the saving on a used one. And when the time comes to sell or trade, a well kept Mercury with a service record holds its value well.

Alternatives to the Mercury 40 HP 40MLHGA outboard motor

40ELHGA: electric start, long shaft, tiller.

40ELHPT: tiller with power trim.

30MLHGA: lighter manual start 30 with a long shaft.

40MHGA: the same motor with a 15 inch short shaft.

See our Mercury 40 HP outboard motors section and the main Mercury outboard motors category.

Mercury 40 HP 40MLHGA outboard motor for sale: price and worldwide shipping

The current price of the Mercury 40 HP 40MLHGA outboard motor is shown at the top of this page. You can add it to your cart and check out straight away, or if you’d rather talk to a person first, send us a message through our contact page and we’ll come back to you with a full delivered price to your country.

What you get

• Mercury 40 HP 40MLHGA outboard motor, new
• Owner's manual
• Mercury Marine factory warranty from the date of purchase

Propeller and fuel tank can be supplied to suit your boat.

Shipping worldwide

We ship to buyers all over the world. Every motor is packed securely for the journey and sent by courier, freight or sea depending on its size and where you are, with tracking from dispatch to delivery. Import duty and local taxes depend on your country, and we’re happy to explain what to expect before you pay so there are no surprises.

Buying with confidence

Have a read of our refund and return policy, see what other boat owners have said on our customer reviews page, and find out more about who we are on the about page.

Mercury 40 HP 40MLHGA outboard motor FAQ

Does the Mercury 40 HP 40MLHGA outboard motor need a battery?

No, it’s manual start.

How heavy is it?

About 204 pounds.

What shaft length?

20 inches, long shaft.

Do you ship worldwide?

Yes. Contact us for a delivered quote.

Order your Mercury 40 HP 40MLHGA outboard motor

Forty horsepower with nothing electrical to go wrong. Add the Mercury 40 HP 40MLHGA outboard motor to your cart now, or send us a question first. You can also compare it with the rest of our outboard motors for sale.