Spring outboard maintenance
What to do before taking the boat out to launch
Let’s do launch: Your careful and complete winterizing last year is about to pay off. Be sure to monitor cooling water outflow, oil levels, and general performance during the first few runs.
Out of the water
1. Service or replace spark plugs
They will be very dirty from the fogging they received last fall. Whether you are servicing a one-, two-, or three-cylinder engine, the plugs are located at the rear of the engine block and are far easier to deal with out of the water, where you’ll avoid wrenching your back while hanging over the stern, risking dropped plugs and tools. Before pulling the capped wires off the plugs, mark the ignition wire with tape labels (e.g., ”upper cable to upper plug”) to ensure you reconnect in the proper order.
The engine will misfire or not fire at all if the leads are not connected properly. Remove the plugs using your spark-plug wrench and give them a spray of WD-40, then wipe with a clean rag. Plugs that have seen more than a couple of seasons’ use should be replaced.
2. Change the fuel filter
Getting rid of the old fuel that has been stagnating in the filter helps ensure a quick start-up. Most filters are located just inside the cowling; follow the fuel line to find yours. Depending on your engine, you’ll find one of three basic types. Older two-stroke engines may have a circular plastic disc held in place with a single centre screw which, when removed, reveals a screen filter that can be gently cleaned using a small amount of gasoline and an old toothbrush. It lasts a long time, but if it is ripped or has any holes, you should replace it. Newer four-stroke engines have a user-friendly canister-style filter with a mesh element. Remove and clean in the same way, but note that these filters are more delicate; replace if damaged or if the gooey buildup won’t brush off. Not shown are in-line filters, found on some brands of two- and four-strokes, which can’t be cleaned and require replacement as much as once a season. When changing any filter, a little gas is bound to spill, so keep a cloth handy. Be sure to use the recommended part for replacement.
3. Check oil level and condition
Whether your engine is a two-stroke or a four-stroke, oil is the key to long engine life and the level should be monitored carefully throughout the season. Four-strokes use a dipstick (similar to your car’s) with high and low marks to verify oil level (above, left). Oil should appear clean (if you were on the ball and changed it last fall) and its level should be at the full mark. For oil-injected two-strokes, check the oil reservoir level and fill if necessary. Depending on the engine type and age, the reservoir will be either within the engine cowling or remotely mounted near the engine and connected by oil-feed hoses. Check your manual to see if priming the oil-injection system is required after prolonged storage.
4. Check lower-unit gear oil
Since you changed the gear oil last season (you did, didn’t you?), a quick visual check will tell you if any fluid has leaked out over the winter. If no dripping or seeping is apparent, you’re good to go. If you suspect a leak, follow the winter lay-up procedure (see winter maintenance, #6) to drain the oil. Check the condition of the nylon washers that seal the vent screws and the fill screws of the lower unit and replace them, if necessary, before refilling the gear case. If leaking continues, suspect worn prop-shaft seals or a cracked casing — and book an appointment with your marine mechanic for replacement.
5. Clear water intake and outflow
Spiders love to climb in these small orifices (just as they like your propane barbecue valves); a pipe cleaner or a small piece of wire can be used to clear out any flow-clogging debris.
Use the grease or oil recommended in your manual or by your dealer to lubricate the gear shift and throttle linkages, engine mounting clamps, and cowling release mechanism — in short, anything that moves. Some engines have grease-gun fittings at pivot points for turning and tilting the engine.
In the water
7. Secure the engine to the transom, ensuring the engine mounting clamps are tight. It’s a good idea to have a safety line, chain, or cable fastening the engine to the boat as well.
8. Install the freshly charged battery, if your engine uses one, making sure terminals are clean and the clamps are tight.
9. Open the vent on your fuel tank and hook up the fuel line, checking for leaks as you squeeze the bulb and prime the line.
10. Start the engine. Don’t be alarmed by white clouds of smoke at start-up; they’ll dissipate as the fogging oil burns off (you did spray that in last fall, didn’t you?).
11. With the engine running at a fast idle, check for a solid stream of cooling water outflow. Weak (dribbling) or absent discharge means the water intakes or outlets are blocked. Shut down and check. If the problem continues, it’s likely the impeller is damaged. The impeller, located in the lower unit, should be replaced at least every four to five seasons as it will crack and fail with age and use, leading to an overheated engine and catastrophic (i.e., expensive) results. This is a job for your dealer but make it a habit to glance back to check the telltale water flow from your engine on a regular (every use) basis.
12. Test drive. Check for smooth steering, shifting, and acceleration. Rough running or overheating requires a review of your work. If you stuck to the plan but still have problems, make an appointment with the pros.
This article was originally published on May 15, 2007