Choosing Between Rebuilding or Repowering Your Marine Engine

Blog | May 27th, 2021

Installing a new, technologically advanced YANMAR engine will instantly breathe new life into your boat. With the right system, you will benefit from: Improved acceleration, power, and responsiveness. Rebuilding an existing engine(s) is an alternative option to repowering. This route is commonly perceived to be an easier and less costly choice. However, this may not always be the case, and if it is, these may only be short-term benefits. Here is how you can choose between rebuilding or repowering your marine engine.

Rebuilding Your Marine Engine

Many existing parts are often not replaced during a rebuild. These parts can include, but are not limited to, the alternator, starter, and water pump. The remaining life expectancy of these parts cannot be predicted and could require further maintenance, downtime, and expense. Rebuilding an engine could also take more time and could present additional, unexpected costs.

By contrast, the installation of a new YANMAR engine guarantees that all of the components are new and the system is covered by our extensive manufacturer’s warranty. It will also likely incorporate the latest state-of-the-art technology, which will deliver rewards on both an economic and performance level.

Repowering Your Engine

Lower running costs and increased uptime, Enhanced fuel efficiency and lower environmental impact. Upgrade to the latest electronics, controls, and diagnostics with interconnectivity to modern multi-function displays. An overall smoother, quieter, and more pleasurable boating experience.

YANMAR marine engines are renowned for their durability and long lifespan. The point at which your YANMAR or other diesel system will need repowering cannot be determined based on the number of operational hours alone. An engine’s longevity is often subject to how regularly and consistently you run your system.

You should consider repowering if your existing engine is becoming increasingly unreliable, you are losing horsepower, the engine is consuming too much fuel, and maintenance costs and downtime are rising. Repower your boat because you plan to keep it and reap the benefits of the new engine yourself. The value of your boat will certainly increase with a new engine, but rarely enough to recoup the costs immediately if you are only repowering with the intent to sell. The same is generally true if you convert from gas to diesel. The boat’s value will increase, but not likely enough to fully pay for the conversion.

Choosing Between Rebuilding or Repowering Your Marine Engine

Ultimately, the decision between the two options relies on individual circumstances and requirements. Consider this: if a rebuild is going to cost about 40% or more than the amount to install a new engine, then repowering may be a sounder investment.

YANMAR is the inventor of the modern diesel engine and is continuing to innovate solutions that push the boundaries of marine propulsion into the next century. Meeting the demands of the evolving, modern consumer by providing advanced and sustainable technologies is proudly at the forefront of development at YANMAR Marine International.


Yanmar. (n.d.). Repower with Yanmar. Retrieved May 13, 2021, from Yanmar:



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