Complete Outboard Boat Powerheads
Having the right type of powerhead on your outboard motor can make a difference in how you get around, whether you do marine or freshwater boating. It's the workhorse in your engine, so you need to be sure that it's functioning efficiently. An outboard powerhead can have different features, parts, and needs.What is an outboard motor powerhead?
It consists of a completely assembled motor. That motor is paired with a lower unit and then is connected with a shaft and propeller further down. All of the parts in the outboard powerhead will be contained in a cowl, a hard protective shell that will keep out debris and help with drag reduction. A powerhead for marine or freshwater use will include:
- A block
- A crank
- Top cap
- Bottom caps
- Pistons and rings
- Cylinder: You could go with either a two-, three-, four-, or six-cylinder powerhead. Your options could range from the Evinrude ETEC two-cylinder to a Mercury/Mariner 2.0L 135-150HP six-cylinder unit. The more cylinders, the greater power you will have, as each additional cylinder lets you burn more fuel and get more displacement during each revolution of the engine.
- Stroke: Depending on your boat's outboard engine, you'll need a unit that is compatible with either a two-stroke or four-stroke system. The names of the systems indicate whether one crankshaft revolution translates into two strokes (up and down) or four strokes. The four-stroke systems may be larger, but they've traditionally been more fuel-efficient.
- Horsepower: The greater the horsepower on an outboard motor, the more propulsion and speed you'll be able to achieve. However, more doesn't necessarily equate to better. If you have an engine that's too powerful or heavy, it could tip the bow of your boat too high. The capacity plate on the stern of your boat will let you know what range of horsepower is allowed for your craft.
- 1. Press the latch on the top cover to remove it.
- 2. Unscrew the mounting screws to remove the cowling.
- 3. Remove the flywheel using a wrench and flywheel puller. Pull out the ignition coil.
- 4.Unscrew the bolts that connect the powerhead to the lower unit.
- 5. If it gets stuck, you can use a flathead screwdriver to pry it up and a rubber mallet to gently break the gasket seal.
Do the steps in reverse order when you've decided on which new piece to put in.