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Mercury 50 HP 4 Stroke Problems – Completely Solved

Mercury 50 HP 4 Stroke Common Problems

You made up your mind to go fishing with your boat. However, it seems like your Mercury 50 HP won’t give a start.

Mercury 50 HP EFI FourStrokes is an engine to run an outboard motorboat. It ensures better fuel economy and outstanding performance. Still, it can face problems like any other outboard engine.

So, what are the  Mercury 50 HP 4 Stroke problems?

There are quite a few problems like the Engine won’t start, overheating. In some cases, the Engine doesn’t shift to gears or trims get stuck in the Engine. Moreover, lack of proper maintenance can cause severe damage to the Engine.

This article acknowledges the problem that most of this model has faced. And, it also provides solutions to those problems.

So please, give this a read, If you don’t want to miss any interesting facts.

Mercury 50 HP 4 Stroke Problems- 6 Guaranteed Solutions

Mercury 50hp 4 stroke

Some of the problems could be new to you but we can assure you that you can go through them easily. This segment has been designed to cover every individuals’ knowledge. At the same time, they find solutions to their problems.

Problem 1: Boat Engine is Sputtering and Losing Power

It happens quite often that Mercury 50 HP 4 Stroke engine sputters out and runs out of its strength. It is most likely to happen when you have a filter problem or fouled plugs. For which, your boat motor loses its power.


Reinstall the in-line fuel filter. If you don’t have one, you can at least clear any debris from the filter element and drain any water that has gathered.

Owners of outboard engines should remember to completely vent the engine compartment before restarting. If you don’t, a blocked filter will appear to be insignificant.

Sometimes Mercury 90hp 4 Stroke can have similar problems.

Problem 2: Engine Won’t Start

Mercury 50hp FourStroke Engine Won't Start

Anyone who has ever turned an ignition key understands how frustrating it is to hear nothing. The person might have a bad day seeing his engine won’t start. Especially if it’s hardly making any sound.


Look for the kill switch. Ensure that the shifter is in the neutral position. After that, pay close attention to the starter switch. An ignition switch can become loose in its fitting. And it can allow the entire switch mechanism to revolve with the key.

It’s as easy as getting under the dash and tightening a retention nut or mounting screws to fix this. Even in some cases, Yamaha 115 engines have issues where it won’t make a start. Whereas Mercury Engines are easier to run.

Problem 3: Boat Engine Is Overheating

The temperature gauge’s needle is rising. This nearly always indicates a cooling loop with insufficient water flow. Most Outboards lack radiators and instead rely on the water they float on to keep the engine cool. If the water stops flowing, the engine will overheat and eventually fail.


Investigate the cause. The problem is almost often an obstacle in the raw water input, such as weeds, mud, or a plastic bag. Locate and clean out the intake. Water flow can be slowed by a slack hose clamp or a burst hose. It may lead to spraying damaging moisture around the engine.

Problem 4: Engine Won’t Shift into Gear

You push the gear shift as you draw away from the dock. The boat’s idling speed is never exceeded. The transmission is not engaged by the shifter. You can also check Mercury’s shifting problem.


If you have e-link electrical controls, it could be a fuse. However, because 90% of small boats still use mechanical cable shifts. So that it doesn’t have a jammed or damaged linkage.

Start at the gearbox to make sure the cable hasn’t come loose from the transmission housing’s shift lever.

If the cable has been stuck due to internal corrosion, try wiggling it free. or, if necessary, shift manually at the engine transmission. But, avoid any fancy docking maneuvers.

If the issue appears to be on the transmission side of the linkage then, it could be a transmission failure. And that you won’t be able to fix from the water. Major Boat Transmission problems need to work as an engine mechanic.

You should also keep in mind the shift shaft alignment of Mercury engines.

Problem 5: The Trim Is Stuck on Your Engine

You’ve returned to the ramp, but the outdrive/outboard will not raise. This will prevent you from loading the boat onto the trailer and onto the highway.


Assuming it isn’t a burnt fuse, there is a mechanical/hydraulic issue. The easy approach is to wade outback and manually raise it. You’ll need to know where the trim release valve is located, which is normally a little screw near the outdrive/base.

When this valve is opened, pressure in the hydraulic loop is released. This allows the driver to tilt.

Oftentimes, it can be a sign of a burnt fuse, which has to be replaced.

Problem 6: Lack of Engine Maintenance

Mercury 4stroke Lack of Engine Maintenance

Just because a boat appears to be tidy doesn’t guarantee it’s well-maintained. Dealers tell us from time to time about owners. Owners who were careful about washing their boats but neglected to pay attention to the internal workings.

Most of us dislike maintenance, but a little bit of prevention goes a long way.


To keep track of what needs to be done, create a checklist with your local NMMA-certified dealer. If you stick to that list, your chances of being stranded on the water will be substantially reduced.

We believe the above difficulties are the ones that Mercury 50 HP 4 Stroke Engines face very frequently. Following the step-wise process can lead you to your solution.

Problem 7: The Engine is Misfiring

Misfiring is one of the most common problems with Mercury 50 HP 4 Stroke Engine. It can be caused by a number of things, but the most common culprit is dirty air filters. Cleaning them regularly will help to prevent misfires.

Other causes can include worn or damaged parts, incorrect fuel mixture, and faulty ignition system. Here are some tips on how to troubleshoot and fix misfiring issues:


If your engine is misfiring, chances are that the air filter is the cause. Make sure it’s clean and replacement-ready by checking for debris and checking for cracks or leaks. If you have trouble getting rid of dust and dirt using normal cleaning methods, consider using a vacuum cleaner with a special filter attachment designed for this purpose.

Another common cause of misfires is an incorrect fuel mixture. In order to test this, start the engine and let it idle while you adjust the fuel mixture until you get consistent performance (timing should not be affected). Once you have a good idea of what fuel mixture setting works best for your engine, make sure to keep it in that range always

A faulty ignition system can also cause misfires. This includes problems with spark plugs, cables, or coil packs.


Mercury 50 HP faq

1. How fast will the 50 HP outboard go?

Change your prop (you’ll see a slight boost) or raise your horsepower (you will see more increase). In either case, it’s preferable to rowing. Even a 16-foot boat has a 50-hp four-stroke Mercury engine that can reach 30-35 mph speeds. This depends on how much weight is in the boat.

2. How many hours can you get out of a Mercury outboard motor?

A normal outboard engine, whether two-stroke or four-stroke, should last 1,500 hours. This will last 7-8 years based on an average usage of 200 hours per year. Changing the oil every 50 hours of operation and flushing the engine regularly, on the other hand, can extend the life of your outboard engine to 10 to 20 years.

3. Is 500 hours a lot for an outboard motor?

500 hours is considered “high” in the Midwest, although it is not. I wouldn’t think twice about buying a motor with 1,000 hours on it. But the price should represent its age because the next man won’t be willing to pay top cash for it either. Big 4 strokes have a life expectancy of 5,000 to 6,000 hours.

4. Are Mercury 4-stroke outboards any good?

Mercury 4-stroke outboards

Yes, Mercury 4-stroke outboard engines are good engines. They are reliable and provide good performance. However, they do have some disadvantages. One downside is that they can be more expensive than other types of engines. Another downside is that they tend to require regular maintenance.

5. How fast will a 50 hp outboard go?

Mercury engines offer some of the best performance in the powerboat industry. With 50 HP, a Mercury HP Stroke engine can reach speeds of up to 40 mph. This engine is perfect for those who want high performance and reliability.

Bottom Line

We hope this has given you a better insight into Mercury 50 HP 4 Stroke problems. We’ve tried to cover the most common problems of these outboard motors. By following the steps properly, you’ll be able to solve your related problems.

We believe you got the idea about what you needed. Thank you for staying put this far.

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