Please select your home edition
Edition
Wildwind 2016 728x90

Sailboat Engine Secrets - Change Your Impeller to Keep a Cool Engine!

by John Jamieson on 5 Nov 2011
Figure 1 Captain John Jamieson
When was the last time you checked your sailboat engine raw-water impeller? It's one vital part that keeps your engine cool and happy all season long. In this article, John Jamieson (Captain John) of SkipperTips.com shows you how to make this task simple and easy as 1-2-3:

Your raw water pump draws water from the sea, through the sea-water strainer and up to the engine. In small diesel engines with separate fresh water systems, sea water provides a cooling jacket to lower internal temperatures. In straight raw-water cooled engines, you need every bit of that sea water circulation to keep your engine cool and happy.

Follow the raw water hose from the seacock, through the strainer and up to the front of your engine. Here, you will see the impeller pump cover (see photo of impeller pump). Marine diesel engine guru and author Peter Compton recommends that you follow these steps next along with the illustrations:

Remove the Old Pump.



1. Remove the cover, cover plate and gasket (or O-ring). Look at the vanes and note which way they bend (left or right).
2. Pry off the central plug that holds the vane into the housing.
3. Use two flat-head screwdrivers to carefully pry out the impeller pump. Take care not to damage the vanes.

Inspect the Pump and Pump Parts.

1. Check all around the vanes for cracks, hardening, wearing or melting.
2. If you notice missing chips of rubber, this means particles of rubber impeller could have lodged themselves in the heat exchanger inlet. Follow the hose from the impeller up to the heat exchanger (see bottom photo). Pull off the hose and remove all particles before you start the engine!
3. Check the cover plate for wear (scoring). This reduces your pumps efficiency. Replace the cover plate if scored.

Install the New Pump.

1. Lubricate the new impeller pump with silicone grease or soak it in water.
2. Place the pump into the housing so that the vanes rotate in the same direction as before (you did check this, didn't you?). Replace the plug to hold the pump in place.
3. Install a new gasket or O-ring. Soak the gasket in solvent first to remove packing grease. Lubricate an O-ring with a light grease. Replace the outer cover.

You will keep your sailing boat's diesel engine roaring like a lion when you change your raw water impeller once each year. Follow these simple sailing tips above to add life to your engine and save money in expensive repair costs--wherever in the world you choose to cruise!

John Jamieson (Captain John) teaches sailing skippers the no-nonsense cruising skills they need beyond sailing school. Sign up for his highly popular FREE sailing tips newsletter at http://skippertips.com Become a member for instant access to 425+ articles, video tutorials, newsletters, and free eBooks.

Bakewell-White Yacht DesignBarz Optics - Melanin LensesT Clewring - Generic

Related Articles

Reducing weight aloft with composite backstays
Reducing weight aloft is one of the most cost effective ways of increasing your boat speed and performance. Reducing weight aloft is one of the most cost effective ways of increasing your boat speed and performance. Every kilogram you take out of the rig is roughly equivalent to 4kg added to the bottom of your keel!
Posted on 26 Jul
Free $US3,000 Carbon Vang with SouthernFurl boom orders in July
Southern Spars is giving a free carbon vang - valued at US$3,000 - with SouthernFurl in-boom furlers ordered in July Southern Spars is giving away a free carbon vang - valued at US$3,000 - with all of their SouthernFurl in-boom furlers ordered in July. Carbon gas vangs make a great addition to the furling boom package, though if you’d prefer to keep your existing one, Southern Spars will offer you a 5% discount on the price of your boom instead.
Posted on 29 Jun
Newport Bermuda Race - High Noon takes honours
As the Newport Bermuda Race fleet rushed to the finish line on Monday in the wake of the first-to-finish boat, As the Newport Bermuda Race fleet rushed to the finish line on Monday in the wake of the first-to-finish boat, the powerful 100-foot grand prix Comanche, to the surprise of many they were led by an unusual boat and crew. High Noon, at 41 feet, is fully 59 feet shorter than Comanche and tens of feet shorter than many other entries.
Posted on 22 Jun
Platino recovery - Family confirms that tug has made rendezvous
Reports in social media say a salvage tug has made a rendezvous with the Platino earlier than expected. Reports in social media by family and friends of Nick Saull, the crew member killed during a catastrophic incident abroad the 66ft yacht Platino say the salvage tug which left on Tuesday night has made the rendezvous earlier than expected. The Facebook report says the tug, Sea Pelican, arrived on Friday morning, the weather in the area has eased and with a more favorable outlook.
Posted on 16 Jun
Royal Queensland Yacht Squadron to ban bottled water
Approval has been given to create a ban on bottled water that comes in plastic containers. The RQYS Management Committee has confirmed that approval has been given to create a ban on bottled water that comes in plastic containers. This will place the club as a leader in environmental impact management in Australia and around the world. The Royal Hong Kong Yacht Club earlier this year did likewise. Who’s next?
Posted on 16 Jun
SouthernFurl In-Boom furling systems withstand Sydney Hobart test
Southern Spars design team have developed the SouthernFurl Boom smaller budgets and yachts from 35-70 feet. Have you ever scared your family when you got stuck with too much sail up when you should be reefed? Southern Spars’ range of SouthernFurl booms are the answer – letting you reduce sail quickly and easily without leaving the safety of the cockpit.
Posted on 23 May
2016 Garda Trentino Olympic Week - Day 4
Garda Trentino Olympic Week 2016 draws near to the conclusion: the weather once again proves difficult. Garda Trentino Olympic Week 2016 draws near to the conclusion: the weather once again proves difficult. Tomorrow the medal race is scheduled for the Lasers and another two races for the three paralympic classes.
Posted on 13 May
CCA presents RCC Award to Scott and Mary Flanders
CCA has announced that Scott and Mary Flanders are the recipients of the organization’s 2015 Royal Cruising Club Trophy. The Cruising Club of America (CCA) has announced that Scott and Mary Flanders are the recipients of the organization’s 2015 Royal Cruising Club Trophy.
Posted on 22 Apr
Cyclone Winston Relief Fund – Help the people of Fiji
Sea Mercy is sending volunteer fleet of small and large vessels, loaded with shelter, food and medical supplies to Fiji. Sea Mercy is once again sending our volunteer fleet of small and large vessels, loaded with shelter, food, water and medical supplies and teams to Fiji.
Posted on 27 Feb
Golden Globe Race - 30 sailors from 12 countries named for challenge
Sailors from America, Britain and France head the preliminary entry list for the 2018 Golden Globe solo round the world Sailors from America, Britain and France head the preliminary entry list for the 2018 Golden Globe solo round the world race. The 29 men and one woman – have each paid an initial A$3,000 entry fee. Other entrants hail from Austria, Australia, Brazil, Estonia, India, Ireland, Italy, New Zealand, Norway, Palestine, Russia and Switzerland.
Posted on 18 Feb