a manufacturer's recommended flushing technique:
To avoid injury in the event of accidental starting, be sure to remove the prop and the stop switch lanyard cord from your outboard
All Tohatsu and Nissan
outboards are water cooled; running your outboard without an adequate source of cooling
water will result in severe damage to your outboard.
2.5, 3.5, 4, 5, & 6hp:
For smaller outboards, the simplest way to flush your outboard is by using a large container of water (bucket, pail, barrel). Be sure the container is large enough to completely cover the water intake ports
on the lower unit of the outboard. Also be sure that the container is wide enough so that no part of the motor will touch the sides/bottom of the bucket. Securely mount your outboard on a sawhorse or other sturdy device that will allow safe operation of your outboard. You may also use an optional "flushing plug", see below.
8hp and up:
With 8hp-140hp outboards we recommend you use a motor flusher ("ear muffs"). This type of motor flusher is easy to use, inexpensive, and available at virtually every marine
retailer. This equipment
attaches to your garden hose and clamps on to your outboard's lower unit, covering the water intake ports
. Turn the garden hose on fully before starting your engine. Make sure the "ear muff" motor flusher is firmly in place and correctly positioned over the water intakes on your lower unit. (Note: the "ear muff" motor flusher will not work on outboards below 8hp.
Run your outboard at normal idle speed for 5-10 minutes to allow the engine to warm up and to ensure your outboard is thoroughly flushed with clean water. DO NOT rev up the engine as this is not necessary for flushing and could cause damage to the water pump.
Flushing Plug Attachment:
The flushing plug
attachment is available for all outboards ($14.99). It is a bit cumbersome to use and requires removal
of a water bolt on the engine. Once the water bolt is removed, the flushing attachment can be used. After flushing, the flushing attachment is removed and the water bolt is re-installed. When using the flushing plug method, the engine should NOT be operated while flushing.