How to Tune an Outboard Engine
Regular maintenance of your outboard engine contributes to a long, trouble-free life for the engine and can help you spend more time on the water and less time waiting for your marine mechanic to complete repairs. Tuning your outboard engine at least once a year may mean the difference between a harrowing experience on the water--waiting for a tow as the seas build and your engine is not working--and the reassuring sound of your outboard sparking to life.
Other People Are Reading
Things You'll Need
- "Ear muffs" (special garden hose adapters used to supply the motor with water)
- Voltmeter
- Socket wrench with spark plug socket
- Waterproof grease
- Fuel filter
- Screwdriver
Instructions
-
-
1
Remove the engine cowling (cover) and begin tuning your outboard with a visual inspection of the motor. Look for obvious damage to the fuel and cooling systems, such as cracks, corrosion and worn hoses. Also check for leaks in the fuel line or cooling system as you run the engine (with a proper supply of water to the cooling system). Any evidence of these problems should be referred to a qualified marine mechanic. But if you're comfortable, say, with replacing a hose, then you'll be able to save a few bucks by doing it yourself.
-
2
Check the battery voltage with a voltmeter. It should be between 12 and 12.6 volts when the engine is off. If the voltage is low, the battery should be hooked up to a trickle charger until fully charged. A battery that is not fully charged may cause slow cranking and the motor may not start cleanly. Remove any corrosion on the terminals of the battery.
-
-
3
Disconnect the spark plug wires (label each one with which cylinder it came from so you can put them back in the right order, which is very important). Using the spark plug socket with the socket wrench, remove each spark plug. Install the new ones, being careful not to put too much torque on them--too much torque can damage the plug or strip the threads in the engine block. Only spark plugs that have a heat range that conforms to the standards of the outboard manufacturer should be used. This information may be found in your owner's manual.
-
4
Lubricate moving parts such as the throttle and shift mechanisms and the base upon which the motor turns. Use waterproof grease for these tasks.
-
5
Replace the fuel filter as per the instructions in your owner's manual. Generally, the fuel filter can be found somewhere in the gas line before the carburetor. For most outboards, replacing the fuel filter is a straightforward procedure not requiring any special tools or knowledge. When you have finished, replace the engine cowling.
-
6
Check for water in the lubricant found in the lower unit of your outboard if you did not replace the gear lube in the fall. By taking out the lower drain/fill screw with a screwdriver and allowing a small amount of gear oil to collect in a container, you'll be able to tell if your outboard may need repairs to the seals in the lower unit (the most common cause of water in the gear oil). If the lubricant that you have collected looks milky or cloudy, it's likely that water has been getting into the lower unit, a problem that must be dealt with immediately to prevent more-costly damage.
-
1
Tips & Warnings
Another item that warrants an inspection at the time you are tuning the motor is the propeller. Examine it for cracks, dings in the blades and other damage.
When you run your outboard motor on dry land, you must supply water to it via the "ear muffs." Failure to do so will result in serious damage.
References
Resources
- Photo Credit toy outboard motor image by pearlguy from Fotolia.com
