Boats are usually only as good as the engines that power them, which is why you want to be especially cautious when buying a yacht engine. The larger, wider body of a yacht will naturally slow down any engine, and cause it to suffer more wear and tear than a motor you might attach to a lightweight fishing boat. In turn, you'll want to ensure you don't overlook any details when buying a new yacht engine (like one for Volvo Penta IPS), so note a few simple but important considerations to keep in mind before you start to shop.
Diesel engines are a favourite for yachts since they offer more power than standard gasoline engines. However, diesel engines also typically produce more heat than gasoline engines. You'll then need to ensure that a diesel engine has proper ventilation and a good cooling system, so that it doesn't overheat. Unfortunately, many yacht owners will add thick carpeting and other insulating features to their yacht around the engine compartment, typically to reduce noise, without realizing that they're trapping heat, or they might overlook adding proper amounts of coolant to the engine. Be sure you keep a diesel engine well-ventilated, or choose a gas-powered engine if you know that ventilation and cooling will be an issue with your yacht's engine.
Accessories attached to the engine
A yacht may have more accessories attached to the engine than a standard fishing boat. This will mean more horsepower that is being bled from the engine while it's in use. The more features that you'll need to connect to the engine, the larger and stronger it should be, to ensure the boat itself has enough horsepower for the speeds you want to achieve.
More mechanics will usually be qualified to service a well-known, name-brand engine, and the easier it might be to find parts for a name-brand engine than a more generic brand. However, you might still note nearby service centres and parts stores, if there isn't a service centre at the marina where you will dock your yacht. Yachts are typically more cumbersome to tow to a service centre than a small fishing boat, so when your boat or the engine does need servicing beyond what is offered by a marina, you'll need to arrange and pay for that towing. If there is not a mechanic or service centre near the marina that specializes in a certain type of engine, you might want to shop around for a brand that is more well-known and which can be more readily serviced.