Finbreaker
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- Jan 29, 2016
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I am trying to figure out the simple answer to proper flushing of my 2008 Yamaha F250 4 stroke outboard motor.. My owner's manual gives instructions on how to use the garden hose attachment to flush the power unit part of the motor, then directs me to page 48 for instructions on flushing the cooling system. However, there are no instructions on page 48 for flushing the cooling system! It is ridiculous how difficult it is to find the proper way to flush your motor. After an extensive online search last night, according to Yamaha, any of the three flushing procedures work equally well (hose attachment, motor muffs with engine running, and flush bag with engine running). But some other sources say you have to do the hose attachment flushing process along with the motor muff and engine running flush to open the thermostat and get the whole cooling system flushed. Again, according to Yamaha, the hose attachment flush will flush all areas of the cooling system whether the motor is hot or cold due to small bypass holes in the thermostat that allow flush water to flow through. To add to the confusion, Yamaha adds a small disclosure that the motor muff flushing process may not work on some motors due to multiple water inlet openings on the lower unit on some motors, but in my owner's manual it only shows that my motor has 2 water inlets- one on either side of the lower unit. The reason I am asking this question is that I tried the dual method of flushing my motor yesterday, starting with the hose attachment and the motor off, then attached the motor muffs and started the engine while the water was running. The water came out of the pilot hole just fine when I did the hose attachment flush procedure, but during the motor muff flushing process, I noticed zero water flow out of the pilot hole. I did not hear any alarms or buzzers but immediately shut down my engine, and hope I didn't cause any damage because upon closer inspection- lo and behold I think I have more than two water inlets on the lower unit! Thanks Yamaha for your crappy owner's manual diagrams! Anyway, I am just trying to see if anyone else out there just uses the simple hose attachment flushing method and can this be the one and only method to flush the entire cooling system? I also want to use my Salt Away attachment during flushing but only see the Salt Away being used in videos with the flush muff procedure not the upper unit hose attachment.