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Dangers of Skipping an Outboard Fresh Water Flush

Dangers of Skipping an Outboard Fresh Water Flush

Table of Contents

How to perform an outboard fresh water flush

Maintaining your outboard provides a peace of mind knowing that your motor will function efficiently and reliably down the road. Mercury Marine recommends that you perform a fresh water flush each time your take your boat out. The flush does just what it says, it pushes out dirt, grime and foreign materials that should not remain in your motor. Failure to do a flush can allow corrosion in your motor’s water passages, compromising your cooling system and shortening the life of your engine. It is  great practice to flush your outboard after freshwater outings

Before you get started, be sure have your engine manual handy. You will need this to review instructions that go along with the video.

To start, you will need the following items:

Fresh Water Supply 

Garden Hose

Owners Manual

First, remove the propeller. Refer to your owners manual on how to do this before proceeding. Next, remove the plug from the flush fitting and attach the hose to your engine. Turn the water on to 1/2 flow.  Turn your ignition switch to the on position and run it at idle speed in the neutral shift position. Flush for 3-5 minutes, watching for the water coming out of the Telltale hole.  Monitor the water supply at all times. 

Once complete, turn the engine off, turn the water off. Remove the hose and replace the plug. Lastly, reinstall your propeller.

As always, confirm these instructions with your outboard user manual or call your nearest Mercury dealer for service and parts. 

Along the way, should you discover you need help or specific parts for your Mercury Outboard, remember it is important to choose the best marine parts for your motor. Specifically, choose a OEM parts made by your engine manufacturer. You can pick up the perfect boat parts for your Mercury, Evinrude or Volvo motor at our shop anytime. Avoid the temptation to purchase cheap aftermarket parts on Amazon. Not only do they void your warranty, they just don’t last like the real OEM parts and one of two things happen. You either create more damage by running your engine with broken parts or you end up frequently replacing the cheap parts creating down time and more expense.

Fresh Water Flush for 15-20 HP

Fresh Water Flush for 40-60 HP

Fresh Water Flush for 75-115 HP

Fresh Water Flush on 15-20 HP

FourStroke: I-2 333cc 15hp and 20hp |ProKicker: I-2 333cc 15hp

Fresh Water Flush on 40-60 HP

FourStroke: I-3 747cc 40hp; I-4 995cc 40hp CT, 50hp, 50hp CT, 60hp, 60hp CT

Fresh Water Flush on 75-115 HP

Verado: V-8 4.6L 250hp AMS and 300hp AMS
FourStroke: I-4 2.1L 75hp, 90hp, 90hp CT, 115hp and 115hp CT; I-4 3.0L 150hp; V-8 4.6L 250hp and 300hp; V-6 3.4L 175hp, 200hp and 225hp  
Pro XS: I-4 2.1L 115hp and 115hp CT; I-4 3.0L 150hp; V-8 4.6L 200hp, 225hp, 250hp and 300hp; V-6 3.4L 175hp