The first step is doing your research. You’ll need to identify the repowering options and how each choice may affect your boat’s performance. Critical questions to ask include:

• Is my boat worth repowering from a financial perspective? Truth be told, this is sometimes the toughest question of all to answer. In some cases, particularly with very old boats or those in poor shape which need significant repairs, you may actually devalue the engines by hanging them on the transom. Conversely, with some other boats you may significantly increase the value of the boat-motor package by repowering. This is generally the case when the boat is in good shape but the existing powerplant is not. The best way to research your own situation is to check the used boat market and see what similar models go for with original power, no power, and/or repowered. Check out local classifieds, online sources like Boat Trader or YachtWorld, and the NADA “blue book” values. As you do so remind yourself that repowering is generally not a money-making venture (the Covid-crazy used boat market of 2020/2021 notwithstanding). But hey, why worry about this in the first place? We don’t get boats because it’s an awesome financial move, we get them because we want to go fishing where we want, when we want, how we want — economics be danged.

• Will you do the job yourself, or take the boat to a pro? If you have the gear and know-how to handle the job, completing a repower could perhaps be within your realm. That said, anything with digital gauges and controls and other electronic hardware can get very complex and there are several advantages to having a professional do the job. First and foremost is the busted-knuckle factor. But beyond that, if you do the job yourself and make any mistakes you may lose that warranty coverage. When an Authorized Dealer does the job, you know you’ll enjoy full protection. Plus, pros who deal with repowers day in and day out know to look for things that should be addressed during the process, like transom, fuel system, or electrical system issues. Let’s leave this one up to the professionals.

• What is your boat’s horsepower rating, and how much horsepower do you really want? All boats have a max rating, and exceeding it is generally a bad idea. In some cases, exceeding the maximum can damage the boat, prove to be dangerous, void insurance coverage, or be downright illegal. On the flip side of the coin, settling below the maximum horsepower can lead to sluggish performance and will also make reselling the boat tougher down the road. So, as a general rule of thumb it’s usually a smart move to repower a boat right at its maximum rating.

• Which engine(s) do I need? A lot more goes into answering this question than horsepower alone. You also have to consider shaft length, rigging issues, and weight. Shaft length is usually easy to match, but rigging can be very problematic, especially since some of the newer high-horsepower motors may not fit due to either width or tilt considerations. (Mercury engines are usually designed to fit common transom and engine spacing – a key benefit when repowering). Weight can be problematic too, though it’s less of an issue today than it was a couple of decades ago when repowering a boat designed for two-strokes with heavy early-generation four-strokes was a thing. Drops in weight (now a possibility with new four-strokes equivalent in power to some older models) are advantageous, but increases in weight need to be considered carefully. To get some idea of how a weight increase may affect performance and/or how the boat sits at rest, you can use five-gallon buckets of water. A gallon of water is eight pounds so each bucket equals 40 pounds. Place the appropriate number of buckets as far aft as possible, and see how your boat behaves.

• Can I replace twin engines with a more powerful single engine (or replace a single with twins)? In some cases you may be able to, but the issues we’ve already listed out will dictate the answer. If it is a yes, then you have to weigh the advantages and disadvantages of each option. A single will usually deliver better fuel economy, reduce maintenance and complexity, and lower cost. But for many anglers, especially those who travel far offshore, nothing beats the security of redundant powerplants. Also note, however, that making a switch can mean additional fiberglass work on the transom becomes necessary.

• Which controls, displays, and gauges will I need? If your existing powerplant is relatively modern, the controls and gauges are in good shape, and you go with the same manufacturer, you may be able to dodge a bullet and reuse them. Considering how long many modern outboards live, however, this has become less and less common through the years. Plus, if you’ve been using mechanical controls and gauges you may want to take this opportunity to switch to digital. Today’s digital controls are far smoother than those old cables, and while you may not be able to patch them together with bubble gum and paper clips, they’re shockingly reliable. Digital gauges are also a big step up over the old-tech tachs, as they can deliver intel like fuel burn, engine history, and fault codes at the press of a button.

• What else will I need to upgrade or pay for? On top of the engine itself, its controls, and the gauges, you may need other accessories and/or modifications. Steering can be a big question mark, especially since some of the newer outboards have integrated systems. Existing hydraulic systems may not match up, and autopilots and their pumps may not be compatible with new systems. Then, there’s the helm to consider. It probably has a lot of holes in it already, and you may need to plug some while making some new ones. Also think about networking issues. If you plan to display engine data on your MFD there will be cables to buy and possibly software to upload.

• What will you do with the old motor? Unless you have a second boat with a bare transom, you’ll probably want to sell it and recoup some of the repowering expenses. And even with a blown powerhead, an outboard retains a significant amount of value for its parts. If you’re having a pro do the job they may take it in trade. Otherwise, most people will list the engine online at venues like the classifieds on BDOutdoors.