Freshwater Flushing a Yamaha F300 (2015) in Saltwater

[joshkaj1991]

I am curious how you guys thoroughly flush your Yamaha outboards (2015 F300) with your boats that stay in the saltwater. I know Yamaha has the hose connector on the bottom cowling to run for 15 minutes without the motor on. But I am concerned that does not flush beyond the thermostat. With that said, I was thinking of tilting the motor up, using a flushing bag, surround the motor and water inlets with the bag (not getting any/as little as possible saltwater in the bag), tilting the motor back down keeping the rim above the waterline, filling the bag with a freshwater hose, run the motor with the freshwater hose continually running as to dilute the saltwater, then trim the motor back up and remove the bag.

Is that a sound process or have you guys done something differently to completely flush the motor? Or any reasons as to why this wouldn't work. We cannot pull the boat out of the water after each use to flush it. It is in a slip (SoCal).

Thanks for the input!

 

[Antidote]

You are working WAY too hard at this. Connect to the flush port like your owners manual says. If it make you feel good use a little Salt Away.

 

[Ozdogg]

joshkaj,

I keep my Parker in the marina 100% of the time and run water through the port, just like the manual says and just like Antidote said, I also run a little salt away through it. After 2 years, no issues to report.

 

[Andy]

I am curious how you guys thoroughly flush your Yamaha outboards (2015 F300) with your boats that stay in the saltwater. I know Yamaha has the hose connector on the bottom cowling to run for 15 minutes without the motor on. But I am concerned that does not flush beyond the thermostat. With that said, I was thinking of tilting the motor up, using a flushing bag, surround the motor and water inlets with the bag (not getting any/as little as possible saltwater in the bag), tilting the motor back down keeping the rim above the waterline, filling the bag with a freshwater hose, run the motor with the freshwater hose continually running as to dilute the saltwater, then trim the motor back up and remove the bag.

Is that a sound process or have you guys done something differently to completely flush the motor? Or any reasons as to why this wouldn't work. We cannot pull the boat out of the water after each use to flush it. It is in a slip (SoCal).

Thanks for the input!

Hey Joshkaj, Here's my 2cents; Our boat is kept on a lift. I use the flush port on our 2014 300 Yamaha, and flush for 15-20 minutes every time the engine is run. (Some say 5-10 minutes is enough? I don't know, so I do 15-20 minutes; occasionally longer, as I get busy and forget about it. Never shorter than 15-20)..... I don't know what all is being flushed inside the engine. Water comes out the tell-tale for the entire time I'm flushing, most of the time; but not always (our county water system has 'pressure issues' occasionally). While flushing I go from full up tilt, mid-tilt, to full down tilt in roughly 5-10 minute intervals; I've seen a difference in what comes out the tell-tale as I do this sometimes. I've changed the thermostats twice in 1000 hours. Both times the thermostats looked like new; zero corrosion; it was hardly possible to tell them from the new ones I replaced them with. Most of our boating is in eastern NC rivers, sounds and creeks. The rivers and creeks are 'brackish-to-salty', depending on rainfall. The Pamlico Sound is salty; about a 2/3 the saline factor as the ocean. If our boating was all ocean or all Pamlico Sound, I too would use the Salt Away that others recommended. (Side note; I have many local friends that seldom if ever flush their engines. They say that running 'home' through the brackish rivers and creeks is all the 'flushing' the engine needs. They might be right, but I'm still religious about flushing.

 

[tomc585]

Flush it with the flush port and enjoy.

 

[joshkaj1991]

Hey Joshkaj, Here's my 2cents; Our boat is kept on a lift. I use the flush port on our 2014 300 Yamaha, and flush for 15-20 minutes every time the engine is run. (Some say 5-10 minutes is enough? I don't know, so I do 15-20 minutes; occasionally longer, as I get busy and forget about it. Never shorter than 15-20)..... I don't know what all is being flushed inside the engine. Water comes out the tell-tale for the entire time I'm flushing, most of the time; but not always (our county water system has 'pressure issues' occasionally). While flushing I go from full up tilt, mid-tilt, to full down tilt in roughly 5-10 minute intervals; I've seen a difference in what comes out the tell-tale as I do this sometimes. I've changed the thermostats twice in 1000 hours. Both times the thermostats looked like new; zero corrosion; it was hardly possible to tell them from the new ones I replaced them with. Most of our boating is in eastern NC rivers, sounds and creeks. The rivers and creeks are 'brackish-to-salty', depending on rainfall. The Pamlico Sound is salty; about a 2/3 the saline factor as the ocean. If our boating was all ocean or all Pamlico Sound, I too would use the Salt Away that others recommended. (Side note; I have many local friends that seldom if ever flush their engines. They say that running 'home' through the brackish rivers and creeks is all the 'flushing' the engine needs. They might be right, but I'm still religious about flushing.

Thanks for the detailed response. I think I will do what all you guys say and just use the flush port and not overthink this. Might use Salt Away too from time to time.

 

[djtheo]

Hey Joshkaj, Here's my 2cents; Our boat is kept on a lift. I use the flush port on our 2014 300 Yamaha, and flush for 15-20 minutes every time the engine is run. (Some say 5-10 minutes is enough? I don't know, so I do 15-20 minutes; occasionally longer, as I get busy and forget about it. Never shorter than 15-20)..... I don't know what all is being flushed inside the engine. Water comes out the tell-tale for the entire time I'm flushing, most of the time; but not always (our county water system has 'pressure issues' occasionally). While flushing I go from full up tilt, mid-tilt, to full down tilt in roughly 5-10 minute intervals; I've seen a difference in what comes out the tell-tale as I do this sometimes. I've changed the thermostats twice in 1000 hours. Both times the thermostats looked like new; zero corrosion; it was hardly possible to tell them from the new ones I replaced them with. Most of our boating is in eastern NC rivers, sounds and creeks. The rivers and creeks are 'brackish-to-salty', depending on rainfall. The Pamlico Sound is salty; about a 2/3 the saline factor as the ocean. If our boating was all ocean or all Pamlico Sound, I too would use the Salt Away that others recommended. (Side note; I have many local friends that seldom if ever flush their engines. They say that running 'home' through the brackish rivers and creeks is all the 'flushing' the engine needs. They might be right, but I'm still religious about flushing.

You mention that you changed the thermostat twice in 1,000 hours. How many seasons of use did this equate to? I ask as I have done mine every other year regardless of hours, and the thermostat does look very clean each time. But for a few bucks, figure it gives me peace of mind...and not worth letting it go longer.

 

[baker]

I am curious how you guys thoroughly flush your Yamaha outboards (2015 F300) with your boats that stay in the saltwater. I know Yamaha has the hose connector on the bottom cowling to run for 15 minutes without the motor on. But I am concerned that does not flush beyond the thermostat. With that said, I was thinking of tilting the motor up, using a flushing bag, surround the motor and water inlets with the bag (not getting any/as little as possible saltwater in the bag), tilting the motor back down keeping the rim above the waterline, filling the bag with a freshwater hose, run the motor with the freshwater hose continually running as to dilute the saltwater, then trim the motor back up and remove the bag.

Is that a sound process or have you guys done something differently to completely flush the motor? Or any reasons as to why this wouldn't work. We cannot pull the boat out of the water after each use to flush it. It is in a slip (SoCal).

Thanks for the input!

How would you hold the bag in place?

 

[tomc585]

How would you hold the bag in place?

Bungee cords

 

[warthog5]

Waterpump Kit every 200hrs.... @ that same time...a Thermostat & Pop off valve

 

[Andy]

You mention that you changed the thermostat twice in 1,000 hours. How many seasons of use did this equate to? I ask as I have done mine every other year regardless of hours, and the thermostat does look very clean each time. But for a few bucks, figure it gives me peace of mind...and not worth letting it go longer.

I'd say do as you are doing now; what makes you comfortable. There are a lot of variables to what is needed based on how someone uses and maintains their boat, and where they're boating. For example, some folks boat only on fresh-water lakes or rivers, and there are some who are always in salt water and go far off shore; their needs are different.... In my case, I mentioned above I'm mostly in brackish water, or low salinity sound waters. Although I 'check' the t-stats every season, I've changed them only twice so far, and will change them again this spring. 2023 will be the start of my 6th season with this boat. That equates to replacing them about every two years. I check them every season; I just don't replace them as often. I've seen other peoples salt-encrusted and corroded thermostats that need replacing every season/year, and sometimes more often. My bet is the engines are run only in high-salt ocean water, and are not flushed very often, and/or for too short of time. There are 'high-rise' boat storage dry-stacks that include flushing as part of their service. I'm sure (?) most of them do a great job, but I've witnessed the 'summer help' teenagers, when busy with a lot of boats waiting, flushing an engine for about 30 seconds.