MERCURY 8 HP 8MLH OUTBOARD MOTOR

Description

The Mercury 8 HP 8MLH outboard motor is a smooth twin cylinder four stroke with a 20 inch long shaft, manual start and Mercury’s one handed multi-function tiller. It’s a favourite for long shaft jon boats, skiffs and small pontoons, and it’s one of the most popular kicker and sailboat auxiliary motors we sell. We have it for sale new, with the Mercury factory warranty and a 3.2 gallon fuel tank in the box, and we ship it worldwide.

If your boat has a 20 inch transom or bracket and you want more than a single cylinder motor can give you, the Mercury 8 HP 8MLH outboard motor is a very sensible pick. Here’s the detail.

On this page:

• Why the Mercury 8 HP 8MLH outboard motor
• Three jobs it does well
• Checking your shaft length
• The tiller and controls
• Features
• Specifications
• Maintenance
• Alternatives
• Price and shipping
• FAQ

Why the Mercury 8 HP 8MLH outboard motor

It’s the combination that makes it popular. A 208 cc twin cylinder engine that runs smoothly and quietly. A long shaft that suits taller transoms and brackets. Manual start, so there’s no battery needed and nothing to go flat. And a weight of about 84 pounds, which is still portable for a motor this capable.

Two cylinders give you a much smoother idle and less vibration through the tiller than the single cylinder portables. That makes a real difference on long days, and it’s one reason the Mercury 8 HP 8MLH outboard motor is so good for trolling. The engine uses a single overhead cam and pressurised oil lubrication with a low oil pressure warning, and a thermostat keeps it running evenly in cold water.

Fuel comes from a 3.2 gallon remote tank with a quick connect line, both supplied. That’s plenty of range for a full day of fishing or several trips in and out of harbour.

Three jobs the Mercury 8 HP 8MLH outboard motor does well

1. Main motor for a long shaft jon boat, skiff or small pontoon

Many jon boats, skiffs and small pontoon boats have a 20 inch transom. The 8MLH gives them a smooth, efficient main motor that’ll plane lighter boats with one or two people aboard and push heavier ones at a steady cruise. Shallow water drive helps in rivers and weedy lakes.

2. Trolling kicker on a bigger fishing boat

Anglers with a larger fishing boat often fit a small kicker alongside the main engine for trolling. Big engines don’t like idling for hours and often troll too fast. The Mercury 8 HP 8MLH outboard motor runs happily at low speed all day, uses very little fuel doing it, and gives you precise speed control for trolling. The long shaft suits most bigger boat transoms and kicker brackets.

3. Sailboat auxiliary

On trailer sailers and small keelboats, an 8 hp gives you real reserve power for headwinds and tides. The long shaft keeps the prop in the water on a bracket, and reverse on the tiller makes docking easy. For heavier sailboats this is often a better choice than a 5 or 6.

Checking your shaft length

Measure from the top of your transom or bracket down to the bottom of the hull. About 20 inches means this long shaft is right. About 15 inches means the short shaft 8MH. About 25 inches means extra long, like the 9.9MXLH. On a kicker bracket, check that the prop sits deep enough when the bracket is lowered. Send us a photo if you’re unsure.

The tiller and controls

Everything is on the tiller: forward, neutral and reverse shifting, twist grip throttle with tension adjustment, steering, and the stop switch. You can run the boat with one hand. The auto ratchet system lets you lift the motor to one of several tilt positions without fiddling with pins, and there’s a shallow water drive setting. Start in gear protection means it only starts in neutral.

On the water the Mercury 8 HP 8MLH outboard motor idles smoothly, shifts cleanly and is quiet at trolling speed, with the exhaust leaving through the prop hub. Full throttle is 5,000 to 6,000 rpm.

Mercury 8 HP 8MLH outboard motor features

• Smooth two cylinder four stroke engine
• 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 and trim tab
• Multi-function tiller with forward, neutral and reverse
• Adjustable steering tension control
• Twist grip throttle with tension control
• Thermostat controlled water cooling
• Auto ratchet tilt and trim
• Shallow water drive
• Quiet through propeller hub exhaust
• 3.2 gallon fuel tank and fuel line
• Start in gear protection
• Low oil pressure warning
• ESG over rev protection
• Safety lanyard stop switch
• Owner’s manual
• Mercury Marine 3 year warranty

Mercury 8 HP 8MLH outboard motor specifications

See Mercury’s FourStroke outboards page for the manufacturer’s overview. Some recent small Mercurys use fuel injection, so ask us if you need to know exactly which version is in stock.

Maintaining the Mercury 8 HP 8MLH outboard motor

Fuel: fresh 87 octane with no more than 10% ethanol. Kickers and sailboat auxiliaries can sit for long periods, so disconnect the fuel line and run the carb dry before any long break.

Oil: about 800 ml of 10W-30. Check before each trip. Change at 20 hours, then every 100 hours or yearly.

Gear case: change the lube yearly and look for milky lube.

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

For boating safety basics, see the US Coast Guard boating safety site.

Using the Mercury 8 HP 8MLH outboard motor as a trolling kicker

If you’re buying this as a kicker, a few tips will help you get the most from it.

Mounting. Most kickers go on a dedicated kicker bracket beside the main engine, which lets you raise the motor clear of the water when running on the big engine. Make sure the bracket is rated for the weight and that the prop sits deep enough when lowered. Keep enough clearance between the kicker and the main engine so they can’t touch when both are turned.

Steering. You can steer the kicker with its own tiller, or link it to the main engine with a connector bar so the boat steers from the helm. Many anglers find the link bar makes long trolling runs far more relaxed.

Fuel. Run the kicker from its own 3.2 gallon tank, or plumb it into the boat’s main fuel system with the right fittings. A separate tank keeps things simple and gives you a backup fuel supply.

Speed control. The tension adjuster on the twist grip throttle lets you set a precise trolling speed and leave it. Small changes make a big difference when you’re chasing fish at a particular speed.

Get home insurance. A kicker isn’t just for fishing. If the main engine fails, the kicker will get a mid size boat home slowly. That alone has saved plenty of days on the water.

Buyer questions

“8 or 9.9 for a kicker?”

Both are popular and both weigh the same. The 9.9 gives a little more push on heavier boats and in wind. The 8 costs a little less and is plenty on mid size fishing boats. If your boat is on the heavy side, or you troll in rough water, lean towards the 9.9.

“Do I need electric start?”

Not necessarily. The manual start is simple and there’s nothing to go flat. But if the kicker is mounted where it’s awkward to reach the starter cord, electric start on the 8ELH can be worth it, and it also charges your battery.

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 8 HP 8MLH outboard motor somewhere dry. Twenty minutes in autumn saves hours of frustration in spring.

Paperwork, warranty and keeping records

When your Mercury 8 HP 8MLH 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 8 HP 8MLH 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 8 HP 8MLH 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 8 HP 8MLH 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 8 HP 8MLH 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.

Setting up the Mercury 8 HP 8MLH outboard motor

Get a second person to help lift it the first time. Centre the motor on the transom or bracket, tighten both clamp screws firmly by hand and tie a safety line from the motor to the boat. Use the auto ratchet tilt to set the running angle so the motor is close to vertical with the boat loaded normally.

Secure the fuel tank where it can’t slide, connect the quick connect line, open the tank vent and squeeze the primer bulb until firm. Check the oil. Clip on the lanyard, put the tiller shift in neutral, set the choke and start. Check the cooling telltale is spraying. Vary the throttle for the first couple of hours and change the oil after 20 hours.

What owners notice first

Almost everyone who moves up from a single cylinder motor mentions the smoothness. The Mercury 8 HP 8MLH outboard motor idles evenly and doesn’t shake the tiller in your hand. On long trolling days that’s a real comfort. The second thing is how easy the tiller controls are once you get used to them. Shifting, throttle and steering in one hand soon feels natural, and you wonder how you managed with a gear lever on the side of the motor.

Fuel use

At trolling speed, the Mercury 8 HP 8MLH outboard motor sips fuel, and a 3.2 gallon tank lasts a long time. At full throttle it naturally uses more. As with any small boat, easing off a little from full throttle usually costs very little speed while saving a noticeable amount of fuel.

Alternatives to the Mercury 8 HP 8MLH outboard motor

8ELH: the same motor with electric start and charging. Ideal if you already carry a battery.

9.9MLH: same weight and engine, a bit more power.

6MLH: lighter single cylinder with a built in tank.

9.9MLH Command Thrust: bigger gearcase and prop for heavy boats.

See all our portables in the Mercury 9.9 HP section and the main Mercury outboard motors category.

Mercury 8 HP 8MLH outboard motor for sale: price and worldwide shipping

The price of the Mercury 8 HP 8MLH outboard motor is at the top of this page. Add it to your cart, or contact us for a delivered quote.

In the box

• Mercury 8 HP 8MLH outboard motor, new
• 3.2 gallon fuel tank and quick connect fuel line
• 3 blade aluminum propeller, fitted
• Owner’s manual
• Mercury Marine 3 year factory warranty from the date of purchase

Shipping

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

Buying from us

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

Mercury 8 HP 8MLH outboard motor FAQ

What shaft length is the Mercury 8 HP 8MLH outboard motor?

20 inches, long shaft.

Is it a good kicker motor?

Yes, it’s one of the most popular kicker sizes.

Does it come with a fuel tank?

Yes, a 3.2 gallon tank and line.

How heavy is it?

About 84 pounds.

Is it new?

Yes, with the full Mercury factory warranty.

Do you ship worldwide?

Yes. Contact us for a delivered quote.

Order your Mercury 8 HP 8MLH outboard motor

Smooth, long shafted and simple to run. Whether it’s pushing a jon boat, trolling on a big boat’s transom or getting a sailboat home, the Mercury 8 HP 8MLH outboard motor does the job well. Add it to your cart, or ask us a question. You can also browse all our outboard motors for sale.