The Three-Year Tune-Up: Catching up On Maintenance

distributor cap, spark-plug wire

Spark plug wires and distributor caps should be inspected annually.

Our boats are now on the water after a couple of unusual years — if we did get out it was checkered with restrictions, lockdowns etc. etc. and etc. So this year, there was lots to do before launch — bottom-painting, polishing, cleaning, engine check-overs and the installation of three years’ worth of  birthday and Christmas electronic doo-dads.

By now, most of us have had a chance to enjoy some time on the water. Some of us get to experience quality time in the sun and surf. Smooth sailing, as it were. For the rest of us, though, the first few trips of the season uncovers problems, repair needs and reminders of maintenance items left over from last year (or the one before that)

Tune Up Time

The battle of boater looking for a marine mechanic and a marine mechanic trying to find more hours in the day begins. In much of North America, the marine industry is seasonal. Mechanics get used to the types of questions and service requests that come depending on the time of year: winterizing and shrink-wrapping at the end of the year. Spring start-ups and cleaning in the early spring. With summer in full-bloom, we’re in “tune-up” season.

marine distributor, points and condenser-style distributor

An older points and condenser-style distributor. It has largely been replaced by electronic ignition in modern engines.

The term tune-up means different things to different people — partly as a function of the era and complexity of vehicles (including cars and boats) that you’ve been exposed to.

To understand some of this, it’s important to break down the three things an engine needs to run.

  1. Fuel — to feed the engine
  2. Spark — to ignite the fuel
  3. Compression — to have an ideal environment for the controlled explosions to take place inside the combustion chamber.

A traditional old school "tune-up" would involve the cleaning and replacement of the distributor’s internal components (ensuring that spark is available), adjusting the engine timing, cleaning and adjusting the carburetor (providing the right mixture of fuel) and other assorted maintenance items.

Today’s engines need the same basic things to function (fuel, spark and compression). They are more complex, yet are designed to require less maintenance. That said, they still develop run-ability issues based on a lack of spark or fuel.

Racor, fuel filter, fuel-water separator

A fuel-water separator with a clear bowl on the bottom allows for visual inspection of the fuel.

Spark: only a small percentage of boats operating today require adjustment to points and condensers. Distributors are still found on modern engines, but they are electronically controlled and adjusted. 

Fuel: There is an even mix of engines that are EFI based (Electronic Fuel Injection) and carbureted. Carburetors need occasional cleaning and adjustment. The biggest change in the last decade with respect to fuel is ethanol. It’s an alcohol additive that helps reduce emissions in automobiles — but wreaks havoc in seasonal equipment (boats, lawn equipment, snowmobiles and ATVs).

Ethanol attracts water and causes fuel to break down over time. It damages gaskets, diaphragms and fuel lines. Boaters should be aware of this and try to use ethanol-free fuel or gasoline with additives to combat ethanol. Fuel filters are an essential innovation to have aboard. A fuel filter removes contaminants and separates water from the fuel, preventing the water from reaching the engine and causing rough starting and running.

Today, we can name, classify, diagnose and repair an engine — and many of these run-ability issues will be similar from boat to boat.

Mercury fuel-water separator, water-separating fuel filter

A spin-on canister-style water-separating fuel filter.

Three Common Issues

Boat A starts and runs well at dock. While underway, it seems to lack power. The operator pushes the throttle, the rpms increase, but the boat doesn’t go faster. In many cases, this is an issue with spark. Spark plugs may be fouled. The distributor’s rotor may have developed corrosion, preventing it from making a strong electrical connection.

Boat B has trouble starting. The throttle needs to be pumped before starting and it takes a few attempts to get it started. Once running, all appears fine. Away from the dock and out in open water, the operator advances the throttle, hoping to get on plane and the engine bogs. Rather than getting faster and taking off, it slows down and gets sluggish. It almost seems to groan as it’s urged forward. In many cases, this is caused by water in the fuel. The fuel filter may need to be removed and replaced. Water may need to be removed from the fuel (or fresh fuel added).

The operator of Boat C can’t start the engine. Sometimes it makes a clicking noise when the key is turned. Other times no sound is made. After a few turns of the key and a few clicks, the engine starts. There seems to be no pattern to when the engine will start. This can be pared down to a battery or power issue. Because of this, the operator will be tempted to buy a new battery and install it only to experience the same issues. Where this is a power issue, it may not be due to a failed battery. It could be related to the starter solenoid, a device that delivers power to the starter motor when the key is turned. The clicking noise is the solenoid engaging, but not delivering power. When there is no clicking noise, it indicates that the solenoid is on its last legs

deep-cycle marine battery, marine battery

If you need to replace your battery make sure you get a marine deep-cycle model.

In each of these cases, the operator may ask for a tune-up to be performed — but the mechanic should be able to quickly look at these symptoms and determine more precisely what’s needed, rather than recommending and billing for a generic ‘tune-up’

What can you do to stay on the water longer between tune-ups? Here are a few maintenance items to help avoid some common modern problems:

Routine Maintenance

  1. Change the spark plugs per manufacturers recommendations, or when needed. Inspect and clean at least annually.
  2. Buy ethanol-free fuel, and ensure that you have a water-separating fuel filter installed between the boat’s fuel tank and engine
  3. Replace the fuel filter annually and check it for water regularly
  4. Maintain your battery per manufacturer’s recommendations and keep a voltmeter onboard to test the battery’s strength regularly.
  5. If run-ability issues persist, see your local mechanic for a more in-depth diagnosis.

Spark plugs, Champion spark plugs, marine spark plugs

Replacing spark plugs annually is an easy way to keep an engine running smoothly.

A final thought: If you’d like a tune-up, request one. What you’ll get is an evaluation of the ability of the engine to create spark, deliver fuel and provide compression. The mechanic will test each of these elements and may make adjustments or replace components that are necessary to run ideally. If your engine is new to you, won’t start  or has been sitting unused for a substantial length of time, you’ll want to have a tune-up performed.

Proper maintenance is the best way to stay on the water and make the most of this boating season.

Andrew McDonald is the owner of Lakeside Marine Services – a boat repair/ maintenance firm based in Toronto. Andrew has worked in the marine industry for 12 years and is a graduate of the Georgian College “Mechanical Techniques — Marine Engine Mechanic”’ program.