Getting your outboard ready for spring launch is just one of the projects ahead of you in the full commissioning checklist, and it’s often sort of a good news/bad news affair for boat owners. The good news is that if you properly winterized your four-stroke outboard or your two-stroke outboard before you laid up the boat last fall, getting it going should take no more than 30 to 45 minutes. The bad news is if you didn’t winterize it, you’ve likely got a long weekend or a costly visit to your marine service center ahead of you to catch up on preventative maintenance tasks.
Either way, simply plopping the boat in the water, starting your outboard(s), and then blasting out into the unknown isn’t really the best plan. Smart boaters do a thorough check and test run long before that first fine day of warm boating weather hits. Here’s how to get a jump-start:
You’ll find that the tips in this post have a bent toward four-stroke outboards, but the only real differences between most two-stroke outboards and four-stroke outboards are that two strokes are generally a little less complex, and there’s no engine oil to worry about. And just like the old saying goes, size usually doesn’t matter. Your small four-stroke outboard has spring commissioning needs similar to those of a larger one.
The first order of business is removing the engine cover/cowling and giving the whole outboard an inspection from top to bottom. First, look for possible pest (mice, rats, squirrels) infestation and wire-chewing activities. While you may be laughing at the moment, you’d be surprised how many outboards are used as temporary housing during winter storage.
Next, check the wiring, hoses, belts, and other one-engine components to make sure they’re in good shape, firmly attached (not loose or dangling), and free from corrosion or other damage. This is also a good time to find leaking fluids such as fuel, oil, or cooling water. Check hoses for cracks and broken hose clamps, and make sure all wire ends are securely attached to their termination points.
Spark plugs are less of a problem on outboards than they used to be (especially on four-stroke outboards), but that shouldn’t stop you from removing each one, inspecting it, and checking its gap, unless you did this during layup. Make sure you follow your manufacturer’s specific instructions for spark plug removal and installation, and also for gapping. If you’re not comfortable with the procedure, certainly don’t attempt it. (That goes for just about everything in our outboard spring commissioning tips.)
Once you’ve inspected everything under the cowling, have a good look at the outside of the outboard all the way down to the lower unit. Here you’ll check for corrosion, dents, or other damage, especially around the propeller and lower unit area. Replace any external zincs that are corroded beyond two-thirds of their original size, and repair (or have repaired) any damage you’ve noted on the lower half of the outboard itself. Many four-stroke outboards also have internal pencil zincs that require changing periodically; check those, too, while you’ve got zincs on the brain.
We’re going to assume (or hope) that you or your service pro changed your lower unit oil before layup. It’s not only an extremely inexpensive way to keep your lower unit humming along; it’s also a great way to ensure you’re starting the season with a full load of fresh gear oil. If you’re not sure whether you did, didn’t, or can’t remember the last time you did, now’s a good time to drain your lower unit oil and refill it according to your manufacturer’s recommendations. While you’re down here, check the cooling water intakes for debris or any winter stowaways, such as stinkbugs or other insects. Give the propeller a whirl (it should spin freely in neutral), too.
Unless you have X-ray vision, you won’t be able to check your cooling water impeller without removing the lower unit. Like everything else, if it’s been ages since you or a pro replaced it, now is a great time to slap a new one in. If you’re interested in how to perform the procedure (or are just curious), check out this video on how to do it yourself.
We also hope that you four-stroke outboard owners changed the engine oil and filter before you stored the engine for the winter. If you didn’t (or again, can’t remember when the last time you did was), head down to your marine supply shop, pick up the right oil and filters for your particular model, and swap out the old oil and filters for new, according to the manufacturer’s recommendations. If you did, give your oil level a check to make sure that nothing leaked out over the winter. Like the lower unit oil, keeping fresh engine oil in your four-stroke outboard is cheap insurance for long outboard life.
Oh, and yet another one from the “hopefully you did this but if you didn’t” department is your fuel filter/water separator, if you have one. Again, if it’s been so long you can’t remember, or the one that’s there is from last season is dirty, replace it. If you’ve got a larger Yamaha outboard, here are some tips on changing the on- and off-engine fuel filters. There are tons of onboard fuel filters in today’s big modern four strokes, so if your outboard hasn’t seen any filter love in a while, it’s probably not a bad idea to get it up-to-date on its service schedule now.
Don’t worry; we’re almost ready to fire up the engine. First, though, you’ll want to check the fuel system. If you are using an external tank, check the outside for leaks, cracks, or any other damage. Next, thoroughly inspect your fuel feed line, bulb, and fuel line clamps. Do the same if you have an internal tank, but follow the fuel line all the way from the engine to where it attaches to the fuel tank (and at every junction, including the water separator/filter). Replace any sections of fuel line that are cracked, worn, or damaged, and replace rusty or damaged hose clamps, too.
For outboard owners with hydraulic tilt/trim, this is a great time to exercise that feature all the way up, and all the way down. It should move freely, and without any pauses or jumps. You’ll also usually find plenty of Zerk (grease) nipples in the trim and tilt area as well as around the steering mechanicals. Give them a good shot of the prescribed lube to keep things sliding along.
Before we turn the ignition key or pull the starting cord, making sure the lower unit is either in the water, or you have a freshwater cooling supply hooked up—either through an internal/external connection or by using “earmuffs” that fit over the cooling intake on the lower unit. While the engine is running, continually check those muffs or other connections to make sure your engine is getting sufficient cooling water. If the engine fails to start, start troubleshooting as recommended by your manufacturer. You can also check out this video on troubleshooting an outboard motor that will not start.
Congratulations, now it’s time to get things started. Follow the recommended starting procedures for your particular model, and then allow the engine to run, in gear and at idle for 10-15 minutes, checking for any signs of leaks, cooling problems, or other issues. Now is also not a bad time to gently take the engine out of gear and into reverse, then back to neutral and forward again.
And essentially, folks, that’s it. While we can’t promise that you’re motor doesn’t have any hijinks planned for you this year, starting off on the right foot will go a long way toward providing a blissful boating season.
Editor’s Note: Earlier versions of this article appeared in May 2016 and May 2017. It was last updated in April 2021.