Easy Fresh Water Flush - Yamaha 9.9

[leehenderson]

You can fresh water flush Yamaha 9.9 Outboard engines from the cockpit without running them. I flush my engines whenever I can get to a fresh water hose. You need to first remove the thermostat. I do not use a thermostat here in the warm waters of South Florida anyway so my thermostats stay removed. The procedure is to remove the end of the piss tube water hose from the fuel pump (on newer engines that is. Old engine piss tube hoses do not go throught the fuel pump. If this is your case just remove the exit end of the piss tube.). Then completely remove the short rubber tube that provides cooling water for #1 cylinder exhaust chamber. Then loop the piss tube hose that you disconnected from the fuel pump back to where you removed the short #1 cylinder cooling water hose, blocking the water exit through the piss tube. Then connect a fresh water supply hose to the #1 cylinder fitting and turn the water on. I run it for 10 minutes. This takes less than a minute to connect once you have the procedure down and it is all done from the cockpit. You will have to rig an adapter fitting for a water hose to a small hose to fit on the #1 cylinder fitting but once you have it it is good all the time. There is no need for ears or a screw in water connecter from under the boat. When home I fresh water flush my engines every time I use the boat. When away I flush whenever I have access to a fresh water hose.