How Much Does It Cost To Repower A Boat?

Repowering a boat is a cost-efficient way of extending the lifespan of your vessel and a great alternative to investing in a brand-new machine. While a boat can be designed to take a beating for several years without costly repairs, a boat’s engine is bound to fade out and become a goner. When your boat malfunctions, consider repowering it instead of buying an expensive brand-new boat or spending a lot of money on continuous engine maintenance practices. But how much does it cost to repower a boat? This detailed boat repowering guide will help you make the right choices at the most affordable prices.

Is It Worth Repowering A Boat?

Many boat owners are considering repowering their boats because of the recent boom in outboard motor sales. Repowering your outboard-powered boat is a good option if you can’t afford to buy a new one or if you love the boat you own and wants to add more power. 

A brand new motor gives your boat more power and can also improve fuel efficiency and performance. It can be as simple as keeping the same motor and power and bolting on newer models, or it can be a more complicated project that involves changing the number of engines and horsepower.

Here is a quick look at each of the repowering steps:

1. Going Digital 

New engines mean new features such as monitors, digital controls, fly-by-wire instruments, and plugins with a single electrical wire. Evinrude E-TEC G2 outboards are now available with hydraulic steering, digital controls, and i-Trim automatic trim. Evinrude offers the E-TEC G2 150 with conventional steering for those who want to do repowering projects. 

The brand produces Universal Repower Rigging Harnesses that convert conventional throttles and shift controls from mechanical to digital. V-6 Verado outboards are equipped with digital throttle and shift (DTS), but DTS is optional for models with 200 and 175 horsepower. Yamaha also offers its Command Link Plus system as standard on its V-6 Offshore Series, which ranges from 225 to 300 hp.

2. The Boat’s Current Condition

When planning to repower your boat, the first thing that you need to do is to make sure that the vessel is still sound. Spend a few hundred dollars to hire a good surveyor to determine if the boat is sound. For instance, determine whether the laminate is in good condition. It would help if you also ascertained that the stringers are still properly attached. Sometimes, a boat may have hidden problems even if it looks to be in intact on the outside.

Remember, some boat builders didn’t realize that polyester resin was not waterproof until around 1980. That’s when they started using vinyl ester resin, which is not waterproof. Some boat builders took more time to adopt this material as a skin coat. Boats can become heavy because of additional weight when you head to the water.

Corroding boat repowered
Corroding boat repowered

3. Top Speed

Fortunately, outboard boat owners care a lot about top speed. Engines that have the same horsepower should theoretically be able to deliver the same speed. Other factors that determine performance besides horsepower and weight include lower-unit gear ratios and prop geometry. Every engine is designed to perform a specific job. 

The gear ratios set for each engine are determined by a careful calculation that considers both the weaknesses and strengths of each engine, the performance that owners are looking for, and the prop geometry that the engine manufacturer recommends. 

Some props, such as those with larger diameters and high pitches, will produce a higher top speed than other models, but usually at the expense of other crucial features. Propped up for maximum fuel efficiency while cruising at normal speeds, a boat that produces a high top speed will probably not reach its maximum speed.

4. Power Surge

Many owners want to take a bigger position on the boat to have more power; it is part of the repowering process. First, check the engine’s capacity on the boat to see if it is rated to make the horsepower you want. If the old engines had the maximum horsepower, that’s what you should go for. Do not exceed the maximum horsepower the USCG recommends for a boat with a particular weight or size. It doesn’t matter if the weight of the new engines is the same as the old engines; the horsepower of the old engines will limit the horsepower of the new engines.

5. Weighty Questions

After repowering your boat, it is time to purchase new outboard motors. Four-stroke outboard engines are designed to be heavier than the two-stroke versions. Some boat manufacturers advise against replacing two-stroke outboard engines with heavier four-stroke engines because the transoms were not built to handle them. 

Today, most outboard engines are similar in weight to each other, so it’s no longer an issue for consumers to decide which engine to get. Whenever you make weight comparisons between two outboard motors, be sure to use the same shaft lengths and components. 

For example, the Evinrude G2 engines feature internal steering gear and oil tanks. In contrast, most other engines rely on external steering gears and oil tanks, which aren’t included in an outboard engine’s weight but are required by law. 

There are more robust gear cases for two-stroke engines. It was traditional to design outboard motors specifically designed for use in fresh water and to run at high speeds; that meant that the lower unit gear cases were as fine as possible to reduce weight and drag.

Lightweight boat
Lightweight boat

6. Two-Stroke or Four-Stroke?

Earlier 4-stroke engines were first introduced in the 1980s and offered better fuel economy but less low-end torque. But many things have changed since that time. Two-stroke outboard engines still provide the power needed to deliver low- and mid-range torque – something that towing-sport enthusiasts and bass anglers really care about. 

Evinrude G2 outboards are more fuel efficient than many 4-stroke engines because they are built around fuel injectors that inject the fuel directly into cylinders. But, 4-stroke engines, on the other hand, are getting lighter and have better mid-range torque. 

Mercury Verado 350-hp motor uses a supercharger to give it more low-end torque than 2-stroke engines. The new systems are more reliable and efficient than the old carburetor systems. Most outboard engines are now fueled by one type of fuel injection and do not use the old-fashioned carburetor. 

Some outboard manufacturers inject fuel in the intake manifold, while others inject the fuel directly into the cylinders. Fuel injection systems are reliable and more efficient than old ones that used carburetors.

7. One Engine or Two?

Sometimes going with a big outboard rather than two smaller ones or having a pair instead of three is the smartest choice. Twin 200-hp Mercury Verado outboard motors weigh a combined 1,020 lb. 

One large Mercury Verado 350 can easily reach speeds of 30 knots (80 mph) on a single charge, compared to two smaller Mercury Verado 350 outboard motors that weigh more than that ( about 468 lb.) 

The weight of the combined engine is a little more than 600 lb. resulting in a power-to-weight ratio of 2.55 pounds per horsepower. With the extra weight saved by not having the second motor battery and the rigging for the second gear case, the drag loss from not having the second gearbox in the water would be negligible. Fuel consumption could also be reduced.

How Much Does It Cost To Put A New Motor On A Boat?

A typical marine gasoline engine can run for 1,500 hours before it needs a major repair. On the other hand, diesel engines run for more than three times as long and log an average of 5,000 hours of running time. The number of hours a marine engine can run depends on the quality and amount of maintenance it receives over quality time.

Normally, a gasoline engine on a marine engine will run perfectly for the first 1,000 hours. At this point, the engine can start showing signs of major trouble. It may not be possible for the engine to run for another 1,000 hours. It is at this point that small problems start to occur. If these small problems are not addressed, the engine will have more problems down the road.

Normally, a well-maintained gasoline engine running in excellent condition will run for more than 1,500 hours without a major overhaul. But engines that operate in the most horrible conditions of damp bilges, salt air, pure neglect, and intermittent operation will die early.

When you replace an engine in a powerboat, it costs about $15,000. It costs around $5,000 to $10,000 to replace the motor in a sailboat. If you use a sailboat with a decent outboard motor, you will pay less, around $1,500, since the sailboat uses wind as its power source.

Repowered fishing boat
Repowered fishing boat

How Long Do Boat Engines Last?

An engine is very important for any boat and will last for several seasons without needing to make any major repairs. Even if you maintain good maintenance, your boat may have problems when the engine starts to fail. This is when you start thinking about what it will cost to replace your boat’s engine. 

The duration your boat engine will last depends on the type of boat engine you have installed on it and the fuel you use. Normally, a gasoline engine can run for about 1,500 hours before it breaks down. Diesel engines will last three times as long as standard engines and run for a whopping 5,000 hours on average.

Never forget that neglecting maintenance and performing oil changes improperly can significantly reduce an engine’s lifespan. Modern-day boat manufacturers have designed their motors for long and continuous rides. 

Therefore, if you use your boat only sporadically and only for short trips, it is likely that the engine will fail sooner than if it was used daily. Some estimates say that boaters spend 100 to 150 hours a year on their vessels. That means the engine should last around ten years, maybe even more. 

On the other hand, fishing boats regularly go through more than 200 hours of water each year. There are some warning signs that a certain engine is about to fail, but the most obvious one is a change in the color of your exhaust fumes.

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Repowering your old boat is an affordable option as compared to buying a new machine or continuously repairing the engine for the boat to function optimally. Your decision to repower your boat engine should be guided by various factors such as the boat’s horsepower need, emissions, cost, and fuel efficiency. Evaluating your current specific needs and fishing locations and weighing all your options will help you make an informed decision.

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Brian Hopkins

Brian is an outdoor writer and the youngest member of our team, but he is extremely knowledgeable when it comes to fishing and different techniques for catching different species. He shares valuable information that the younger generation can relate to. When he is not fishing, you can find him hanging with his friends and gaming on his computer.

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