7 Most Common Problems With Mercury Verado 350

This Mercury 350hp verado outboard motor from Mercury’s supercharged Verado lineup is pretty famous for getting its job done with its 2.6L in-line, six-cylinder displacement. 

This has caught everyone’s attention with its powerful, reliable, fuel-efficient, and responsive performance.

That being said, every outboard motor comes with problems, some are serious issues, and others are not. 

Likewise, the Merc 350hp motor is not free of problems.

In this article, I am going to show you the 7 most common problems with the Mercury verado 350 and possible fixes. 

Problems Reasons
Wiring IssuesBad ground wire
Engine Surge and Running Temperature Issuetemp to trigger guardianwire problemvinyl fuel line
Verado Supercharger LeakPowerhead Leakage
Heavyweight issueFor the accessories
Costly price tagIncludes various parts
Power steering pump issueloose connection in the wiring systemignition coil cutting in and out on the starboard engine

1. Wiring Issues

The first problem that a lot of users have experienced is the wiring issue. 

If I portray the possible situations –

  • When turning the key on to start the boat, some users are getting a long beep, and ‘check engine-fault throttle’ appears on the craft gauges. 
  • At the time of accelerating, the head jerks forward, and ‘check engine-fault lever’ also appears.
  • The smartcraft gauges may shut off suddenly. 

If we talk about the reasons and possible fix– 

It is for the bad ground wire. It would be best if you replaced the wiring harness for the DTS and ignition switch. 

So, to replace the wiring harness –

  • You need to first sort out the colors and take measurements of the wires. Since they are color coded, it is easy to separate. 
  • Then cut new wires according to the sizes of the old damaged ones.
  • Now for the connections, you need to splice the wires with the main cord. 
  • For double security, use string tubing to protect the connections. 
  • Now solder the wires. Then wrap again with electric tape for more protections. 

Now you can install the harness. 

2. Engine Surge and Running Temperature Issue

Some of the customers shared their engine surging problem. When the rpm is climbing up, the engine surges back and forth. The temperature also fluctuates unusually.

Possible reasons 

It can happen for the wire problem. So, to get rid of the problem, you may unplug the wire harness and then reconnect it. 

The temp to trigger guardian can also be the reason. 

The vinyl fuel line can also be one of the reasons. The vinyl lining can break down and create restrictions in the filters by getting liquified.

3. Verado Supercharger Leak

Leakage problem is a common issue for motors. Many people experience this in outboard motors. Among them, a customer said that he had got an alarm from smart craft, and it said – low-pressure oil. 

He inspected the oil level with the dipstick, but the oil level was okay. So, after further inspection, he found out that the oil has been leaking out of the air vent of the supercharger. And it was running down to the gasket. 

But the amount of leakage is quite unusual. So, he was confused about what are the possible reasons that might cause the leakage.

So, I am trying to add all the possible causes and give a solution as well. 

The Powerhead Leakage can be one of the reasons as there are a couple of seals that are around the driveshaft. 

When they leak, the engine will run low on oil, which can be a definite problem.

Possible fix

Firstly, you have to do a leakdown-test of the powerhead to confirm the ultimate condition of the supercharger.

A Tip: To get the full performance (10 percent greater fuel economy than competitive outboards), you should use 89 octane gas with 91-octane. 

4.Heavyweight Issue

When the users get this motor, the majority of them have an issue – its weight. This is not at all a lightweight package. It weighs around 668 pounds. For the older hulls, there is nothing much you can do. But mercury has shared some solutions for the current hulls.

Possible fix

This high horsepower 4-stroke model is actually suitable for current halls. They have the proper static flotation in their transoms to bear the mass. And the high thrust level of the motor can drive the bow down. 

So, I recommend always checking any boat’s specs before installing this motor to avoid wet feet.

5.Costly price tag

Some consumers become surprised when they check out the price. This is definitely a few times higher than conventional 4 -stroke motors. However, Verado gives an explanation for this high price tag.

This price includes SmartCraft Digital Throttle and shift, electrohydraulic power steering, 2-speed trim, and so on. 

A Tip: Since this mercury verado 350 goes with the 5.44 HD racing gearcase, you should not go with the lower unit gearcase. This won’t stand up to the applications for the power ratio, torque, and horsepower of the racing engine. 

6.Power steering pump issue

This model comes with power steering at this price. But sometimes, the consumers face power steering pump issues. They thought that it happened for the batteries. So, when they contacted the company, they replaced all the batteries under warranty. But unfortunately, when they went for fishing, the power steering went out. 

However, I am going to be listing all the possible reasons that might cause it and the possible solutions –

These might happen for the loose connection in the wiring system. You should physically triple-check all the connections. 

The ignition coil cutting in and out on the starboard engine can also be another reason. So, you can turn sync off to avoid dragging the port down. 

You can also diagnose the problem by removing the ignition coil harness plug. But be careful about the plugs. Don’t leave them for too long otherwise you will experience an EST open fault. 

Again, you can call Mercury customer service, tell them the part number from your pump, and get the newest pump. The new designs come with a redesigned circuit board to reduce overheating. It also uses the 60 amp blue fuse instead of the red fuse with 50 amp. 

7. Service Issue

If I mention the Achilles heel of Mercury Verado 350, it would be its customer service. Mercury’s customer service is not available all over America.

It is actually disappointing, but it is not in your hands.

Possible fix

You can contact professional workers or check out the manual for troubleshooting. Again, this motor also comes with a warranty, which is actually a boon. 

What majority of the users feel about this mercury verado 350?

The outboard motor experts and the consumers love the engineering and design of this well-balanced, compact machine. 

The best-in-class quietness gained a lot of appreciation. It’s actually more than a mere outboard motor. It is a total drive system. The cold air intake system outside of the cowl is quite great. 

Having said that, yes, there are few users who are a little upset regarding the issues of Mercury 350 that I have explained earlier. 

Some consumers are having trouble with the weight, and some are facing wiring problems. But still, the awesome acceleration, quiet operation, low fuel consumption, supercharged torque, and so on outweigh the problems and offer a premium boating experience. 

Final thoughts 

The mercury 350 hp verado stands the marine industry on its ear. It outpowers 2-stroke engines of equal displacement. The bay boaters and walleye anglers gladly order the 350 after having issues with 300hp. 

However, everything has its drawbacks too. I have mentioned the 7 most common problems with mercury 350hp that users have encountered so far. 

On the other hand, these problems have easy fixes, and this motor performs incredibly well. The boat lovers are pretty happy with this outboard motor. 

If you own a mercury 350hp verado with your boat, then let me know if you have experienced any issue and how did you fix it. 

This might greatly help the new owners of the mercury 350hp.

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