Stern Drive Systems Maintenance Issues

Several weeks ago we asked our readers to describe how their boats performed with the stern drive systems they had. We got good feedback that will help new boat buyers zero-in on the horsepower and lower unit best matched for their application. Our sampling also indicated that owners of stern drive engines are not as satisfied as are those of outboard engines, on average. Perhaps that is not surprising given the fact that modern stern drive systems have so much more equipment outside of the engine housing.

Exhaust risers and manifolds are frequent places for engine trouble. A good maintenance regimen can save nine.	Shifting and throttle linkage controls are a common place for problems "fly-by-wire" solves the problem.	Stern drive bellows are places where trouble can occur and most people take them for granted and neglect inspection.

Happily, most owners of stern drive-powered boats were pleased with their propulsion systems. Even owners of boats that had had problems were remarkably understanding and most seemed more than willing to take a bump or two in the road in stride. Certainly everyone realizes that a boat is the most abused and ill-maintained piece of complex equipment that most people own.

We note that most of the problems that did occur fell into the category of miscellaneous – that is, one of these and one of those, with only a couple of items seeming to be more chronic problems. If fact, we were happy to see that the water ingestion problem that occurred in the early 2000s has pretty much disappeared.

Shifting and Throttle Linkage

A number of the problems that readers mentioned involved issues that involve installation, such as shift linkage. This is perhaps the number-one complaint and was spread across both engine brands. In order to get builders to follow the engine makers recommend installation procedures, both MerCruiser and Volvo Penta have instituted 2-year warranty programs in boat brands that carefully follow the engine company’s program. If you are looking at a boat that has only a one-year engine warranty, you are being tipped off to a problem right from the get-go.

Sensing a Sensors Problem

The second most numerous complaint involved faulty sensors. Heading the sensor list were those for trim tabs, equipment that normally is quite separate from the engines systems. Nevertheless, owners lumped trim tab sensor problems in with problems they are having with sensors on the engines. Sensor failures on turbos were one example that occurred a couple of times, for example.

When sensors can put the drive system into “limp-home mode” and the sensor is faulty, boaters are not likely to be happy campers. One reader said that his engines went “limp” when he was in a critical maneuvering situation near a bridge, another mentioned that it happened while he was docking. Obviously, the system does not know if the situation of the boat is precarious when it decides to go into “limp-home mode” because of what it senses to be a situation critical to the engine’s health. It could be that the health of the owner and his guests should take a higher priority. There seems to be no manual over-ride in these situations.

Warranty Disputes

Most annoying to people with complaints were what are characterized as a rather cavalier attitude of some customer service personnel about engine warranty coverage. Generally, when we speak to companies about warranty disputes we are often told that they are being abused by the customer or the dealer. Finger-pointing between builder, dealer, and engine-maker still goes on from time to time, but, thankfully, it has been greatly reduced from years past.

Our advice to aggrieved owners is always the same: take your complaint to the top – the president or CEO of the companies involved. If you have legitimate request, they can usually fix your problem with the wave of a finger.
If you would like to see our readers’ comments or you would like make some of your own, just click on the brand below and visit our Owners Feedback section.

MerCruiser	Volvo Penta