It goes without saying that one of the most important components of a powerboat is, well, the power. During the boat shopping phase you may overlook a certain model because it does not have the best power package, or the engines have too many hours for your comfort level. And for some boaters, they may already own the perfect boat and love everything about it, but after several seasons the maintenance of the aging engines becomes excessive. This is when you may want to consider a repower.

Yes properly maintained gas engines can run for thousands of hours, and I've seen some diesel engines with more than 10,000 hours still chugging along. But to me, the piece of mind gained by knowing that I have fresh power is tough to beat.

I had the engines rebuilt on an old Pacemaker and in hindsight would have been better off re-powering. Why repower, even if there's the added cost? Well one of the best parts about re-powering is that you get a new engine warranty. That alone is well worth it to me, and in the end is a cost savings. "And don't forget that rebuilt doesn't mean new," says Steve Creel, a Boat Digest contributor and former service manager of Marlow Marine. "A lot of the major components are still used." And these parts, like the alternator, starter, and water pump are items that usually require attention.

Is there a cost-to-value ratio when it comes to deciding to re-power versus rebuilding? Of course not, nothing in boating relating to cost analysis is easy. A lot of it is subjective. However, keep in mind that a re-power may make it easier for you to sell your boat and command a slightly higher price. Although you should not expect to recoup the entire cost of a re-power in the sale price of your boat. Or as the folks at Yanmar say, "consider a repower because you want to use your boat, not sell it."

Another reason for considering the repower is the technology and efficiencies of today's engines are light years ahead of what was available 10 years ago. "We've got a guy with a Bertram 46 who re-powered with new 720s and the performance was was great," commented Scott DuBrow of Yanmar distributor Mack Boring. The 1980 convertible was originally powered by a pair of Detroit 8V-17TI diesels that pushed the stoutly built battlewagon to a speed of about 22 knots. That's top speed! I'm a sucker for the rumble of those old Detroits, but these were heavy engines and today's choices are far more efficient. After doing a lot of shopping around, the owner locked in on a pair of 720 hp Yanmar diesels. What type of speed difference did he achieve with the new engines? Try a top speed of more than 30 knots at 2200 rpm. And at this speed, she was burning a little less than 70 gallons per hour.

BOAT DIGEST contributor Chuck Husick, who ran the boat, also commented that the acceleration out of the hole was impressive, with no black smoke bellowing out of the stern. The computer-controlled engines are far superior to the original power plants. "There's a Hatteras 53 Convertible that was just re-powered with our 900s. Very impressive as well," DuBrow said.

Some companies, such as Williams Diesel offer direct replacement packages. They distribute the MarineDiesel which is a direct replacement diesel for gas V8 engines. When replacing General Motors 5.0L, 5.75L, 7.4L or 8.2L V8s, the MarineDiesel will fit the drive, front engine mounts, exhaust system, most wiring harnesses and is approximately the same weight and size as the original gas engine. This will greatly reduce the labor costs associated with re-powering. Ratings range from 170 to 300 hp. The engine is based on AM General?Ĵs Optimizer 6500 diesel used in the military's HumVee vehicles.

Crusader Engines has also tried to make the re-powering process painless with its Power-Pack. The 300 hp Vortec gas engine has a complete fuel and ignition system, but will utilize the rest of your boat's existing hardware, bellhousing, and exhaust systems, thus reducing the cost.

If you decide to do a re-power, what are other factors that you should consider? One of the most important, after choosing the engine, is selecting the yard. If you want Crusaders, go to a Crusader dealer, if you want Yanmars, call the Yanmar guy. Also make sure they have experience with your horsepower size. Yanmar, for instance, also makes a wide range of engines for sailboats. If your yard is primarily working on the smaller, say 40-hp range, and you're looking at installing new twin 300s, you may want to look elsewhere.

Also when you are comparing bids, make sure you're looking at an apples to apples comparison, and iron out as much as possible before the work begins. I had to hold firm with a mechanic, who kept trying to jack up the bid several times during a rebuild. It was kind of a shakedown, and eventually I had to take him off the job and assign it to the yard that had a higher, but in hindsight, more prepared and realistic bid. Had I checked references, I would have realized this guy was running all over town working several different angles and getting "progress" payments from a few clients. And had I asked for references, I would have realized I hired a schmuck.

Also, even if you are re-powering with the same size engine, make sure the yard considers the engineroom or compartment air intake. Engines that don't get enough fresh air can not operate properly. Remember that engine power will decrease as the temperature of its combustion increases above 77 degrees. I dropped a paper towel once on the cabin sole of a new boat and was amazed to see it quickly sucked towards the door of a starving engineroom. There are several good after market engineroom cooling systems by companies such as Delta-T that can help address this issue.

A good yard will also review the exhaust system and depending upon the type of engine, you may have to modify this during the re-power. On more than one occasion I've talked to boaters who get water in the cylinders on a new engine. The culprit almost always is a poorly designed exhaust system. If the exhaust elbow dips below the waterline and does not incorporate an anti-siphon line in the raw water discharge line, you're asking for problems.

One of the last items to consider and discuss with your yard are the props and shafts. If you own a planing boat, new props are often necessary and desired as part of a re-power. For example, the owner of the Bertram 46 changed his props from 28" x 30" to a pair of 28.75" x 34.64" VeemStar-Cs. Again, this is one of those hidden costs that a yard may not consider.