Solace 0 Report post Posted October 25, 2008 This question probably goes out to MOST. I have a 270 with the thru hull engine cooling design. I recently had to have cooling system cleaned out due to overheating. The dealer found small pebbles and vegatation inside the cooling core. All my friends tell me I should have a forward facing clam shell on the bottom of the boat at the inlet. I just had the boat pulled out for winter and I did not find a clam shell. Is there suppose to be one? If not is there a some type of screen that should be in place to prevent the vegatation from ending up in the engine? Share this post Link to post Share on other sites
The MOST 0 Report post Posted October 28, 2008 Typically, on a thru hull water inlet supply there is no clam shell but often there is a sea strainer (with a cleaning basket) on the inside of the engine compartment, close to the bottom of the engine. A clam shell vent will not prevent small pieces of vegetation or pebbles from entering your engine and retro fitting a small screen covering the intake could potentially starve the cooling system of water. I am assuming you have a Mercury and not all Horizon engines were built with sea strainers (as per Merc specifications). To find out if your engine has one, you can contact Mercruiser at 405-743-6566 in Oklahoma or on line at www.mercurymarine.com or check your engine manual for that information. If you contact Mercruiser direct, you will need your engine serial number. If your engine does not have a sea strainer, the Mercury tech will be able to provide you with part numbers and guidance on installation of one. It would be a good idea to put one in- especially if you boat in shallow, muddy or debris filled water. With the Horizon cooling system that is installed on your engine (or any raw water pick up) the boat operator needs to do the very best at avoiding shallow, debris filled water. Excessively muddy water or stirring up the bottom while close to shore will also cause problems. The water pump on the engine has a powerful intake suction. By moving the boat to clean water and running up on plane for at least 8 to 10 minutes after encountering debris filled water… or accidentally stirring up the bottom in the shallows, you can flush out most pebbles and vegetation from the engine. Share this post Link to post Share on other sites
Solace 0 Report post Posted October 29, 2008 Thanks. That does explain some. My dealer also stated that this model also receives water from the out drive. Is this true? It is a 6.2L horizon engine with the Bravo 3 drive. Share this post Link to post Share on other sites
The MOST 0 Report post Posted October 30, 2008 The Mercury Alpha drives have an internal water pump but the Bravo III's do not. Share this post Link to post Share on other sites