Yamaha 200 running flush question

[Capt’nKarl]

We just returned from a trip in our R-23 and had a blast. The Yamaha engine performed flawlessly and I was careful to make sure there was water being expelled from the engine. We had no engine issues after 5+ hours of use. I got home and while the engine was still warm hooked up the mufflers to the engine water pickup. The mufflers I have spray water out of each side so there was plenty of water available. I turned on the water supply, cranked the engine and waited to see the stream of water coming out from the water pump. After 10-15 seconds no water stream. Plenty of water coming out from the prop but nothing from the water pump. After stopping the engine I then connected the hose for a static flush and that’s when water squirted out the water pump outlet. Am I missing something here? I thought the running flush essentially uses fresh water to cool the engine by running the water through the water pump. Thanks.
Karl

 

[Brian98133]

No expert here, so take this with the proverbial grain of salt... but as I understand it, the F200 (according to my certified tech) has numerous pickup points that the standard 'muffler' doesn't get water to. Aside from the black rectangular pickups, there are other 'holes' which suck up cooling water. When hooking up the flush port, you'll see the water coming out of these pickup holes, so you'll see what I'm saying.

So on these, simply putting the standard muffs will get 'some' water to the pump, but the other pickup points suck in air, lessening the efficiency of the pump, which is bad. Good on ya for noticing this and shutting 'er down!! 😀

I've been told some people wrap Saran Wrap around those pickups, and others use tape of some sort? I would think a flush bag would be a better option.

 

[ixlr8]

On my Yamaha 300, my dealer told me the round muffs that I bought don't seal well enough to get the water into the engine. He gave me a set of rectangular muffs that have a rod that goes thru inlet port to clamp the muffs in place. Only hassle is, he said the plastic inlet filters need to be removed to get the rod thru to clamp the muffs in place. I haven't tried them yet as I have not run the boat since he gave the rectangular ones to me.

 

[tjiann]

Another "take this with a grain of salt" response, but I find sometimes that if I tilt the engine up some it gets the water flowing, then I just gently tilt it back down and everything works fine.

 

[Capt’nKarl]

Thanks for the replies. I can see where the plastic intake covers may divert more water than it’s allowing to go in and it would be a hassle to remove these covers. What I’m trying to figure out is why water was spurting out from the water pump outlet when I was doing the static flush. I guess the water hose pressure was enough to cause this. I’m going to submerge the lower unit in a trash can filled with freshwater and test again.

 

[ixlr8]

Static flush puts water in above the water pump and it flows thru the engine to the outlet. The running flush with the muffs puts the water in below the water pump so it feeds the water pump and you can flush with the engine running. Provided the muff seals properly.

 

[Capt’nKarl]

Thanks Jim. Just to be clear. The running flush with properly applied muffs and adequate water pressure will not damage the water pump impeller? When I didn’t see water coming out of the cowling all I could imagine was the water pump was running dry which couldn’t be a good thing.
Karl

 

[Brian98133]

According to my technician: The static flush port pushes water through every channel in the cooling system... even the pump. The pump has bypass valves that are triggered when the pressure of the static flush is present that allows water to flow through all ports. This includes the pump housing.

This is why, as I understand it, water - during the static flush - comes out of every port, not only the exhaust, but the multiple pickup points as well. Water from the static flush port gets everywhere we need it to get to adequately flush the entire system. When I'm flushing using the static port, water comes out of areas of the unit that I didn't know had holes! 😱

I've seen other posts where others doubt this... but no one has stated that a qualified technician has told them the static flush port is inadequate. I think it's just a matter of "it doesn't feel right if I don't run the engine" - which is something I had to get over as well. But once I applied logic, seeing water flowing everywhere, it has to be correct.

I'd love to hear a qualified tech (Yamaha qualified) tell us that the static port is inadequate, and that we all should have a large sump in which to place the lower unit fully in water and run the engine.

 

[ixlr8]

Thanks Jim. Just to be clear. The running flush with properly applied muffs and adequate water pressure will not damage the water pump impeller? When I didn’t see water coming out of the cowling all I could imagine was the water pump was running dry which couldn’t be a good thing.
Karl

From what I was told by my dealer, verified with a certified Yamaha tech. If running a flush with properly applied muffs and adequate water pressure, it will not damage the water pump to run the engine. IF under any condition you don't see water coming out of the cowling where you normally see water coming out.... then something is not right and you stand a good chance of damaging the water pump impeller running the engine. You did the right thing shutting down the engine when you didn't see anything coming out the cowling.

 

[ixlr8]

According to my technician: The static flush port pushes water through every channel in the cooling system... even the pump. The pump has bypass valves that are triggered when the pressure of the static flush is present that allows water to flow through all ports. This includes the pump housing.

This is why, as I understand it, water - during the static flush - comes out of every port, not only the exhaust, but the multiple pickup points as well. Water from the static flush port gets everywhere we need it to get to adequately flush the entire system. When I'm flushing using the static port, water comes out of areas of the unit that I didn't know had holes! 😱

I've seen other posts where others doubt this... but no one has stated that a qualified technician has told them the static flush port is inadequate. I think it's just a matter of "it doesn't feel right if I don't run the engine" - which is something I had to get over as well. But once I applied logic, seeing water flowing everywhere, it has to be correct.

I'd love to hear a qualified tech (Yamaha qualified) tell us that the static port is inadequate, and that we all should have a large sump in which to place the lower unit fully in water and run the engine.

Hmmm, this is different than what my local Yamaha mechanic told me. He said the static flush port does not provide water to the pump and anything below the pump will not get flushed properly, and not to run the engine while flushing with the static port. I found a Yamaha Master mechanic who teaches classes for Yamaha on their motors. He is about 1 hr away from me, I think I will need to pay him a visit next week and see what he has to say.

 

[BB marine]

There was a recent thread similar to this. The static flush is adequate to flush the block that is what it was designed for by Yamaha. It is nearly impossible for most larger vessels left in the water to freshwater flush the block. Flushing the aluminum block is accentual for longevity if the outboard is used in salt water. Inboard water jackets do not drain there is water in them all the time. Salt water use with raw water cooled inboards deceases longevity but not nearly as bad as an outboard because when an outboard is shut off and the pressure from the water pump is gone all the water drains out of the block. This leaves salt deposits in many "nooks and crannies" in the block add oxygen and it is a formula for corrosion. The same thing happens on the outside of the boat. If you do not rinse the boat with fresh water and leave it covered with salt water, over a period of time metal hardware will start to deteriorate that is mounted or part of the exterior of the boat.

Flushing statically was introduced early 2000's when bigger Bluewater boats were introduced in the market. Big outboards with a big price tag on big boats that stayed in the water. ( Corrosion and outboards) It use to be, when talking about one we're talking about the other. I worked has a servicing outboard technician in New England for a few years and learned to appreciate fresh water. In salt water nothing came apart without a torch, drill, easy out, and many times putting it back together required a tap and thread insert.

Flushing statically on some engines is the best way to do it for the boat owner. The larger outboards have additional low water pickups that require a devise to cover them so the water pump does not suck air and loose prime. The larger outboards 250 hp and up require a lot of water flow to fill the block. Remember the block is draining as it is filling. There is nothing holding the water in the block except the pressure from the pump. The engine water pump is designed to maintain enough water pressure and flow to keep the block full, while discharging the water back out the exhaust.

Flushing with the engine running as someone that worked on outboards and understands the water path of suction and flow to the engine, how the water by-passes the thermostsats and dumps into exhaust housing and drains out all drain ports. I personally prefer Run flush periodically if the boat was dry docked for a period of time. If the boat is left in the water the Yamaha or any other manufactures static flush design is the easiest way to flush the system.

Honestly you could talk to 10 Yamaha certified technicians, 10 Mercury certified technicians, A manufactures training instructor and get many different opinions. The key component is knowing the correct way to flush it for a given model. The larger the engine more water capacity is needed from the hose while running the engine.

If I owned a 200, 250, 300 hp I would flush the engine using the static until I was comfortable with a alternative way of doing a running flush. Every application can be different. If the engine has low water pick ups they must be blocked off when using a flushing muff. The water supply from the hose must be sufficient to supply enough water for cooling. As a service technician anytime I ran an engine on a flushing devise I always had the cowling off so I could touch test the heads for temperature.

 

[Brian98133]

[/quote]I found a Yamaha Master mechanic who teaches classes for Yamaha on their motors. He is about 1 hr away from me, I think I will need to pay him a visit next week and see what he has to say.[/quote]

- Please share! As I stated, this is just what I understand... so I'm looking forward to others' input 😀

Honestly you could talk to 10 Yamaha certified technicians, 10 Mercury certified technicians, A manufactures training instructor and get many different opinions.

- Truer words were never spoken! Same goes for my own industry... which is why I like to hear from many, and this forum is great for that!

 

[Capt’nKarl]

Thanks to everyone who has responded to this thread. My particular situation is the boat is stored on a trailer so it’s almost as easy doing a running flush as a static flush. As someone mentioned running the engine during the flush gives you a sense of comfort something I got used to when flushing my Yanmar diesel. When I double checked all the lower water pickups were covered and there was plenty of water flowing through the muffs and then didn’t see the water stream when I cranked the engine I shut the engine off. It’s a boat so there’s always something.
Thanks again,
Karl

 

[BB marine]

When I double checked all the lower water pickups were covered and there was plenty of water flowing through the muffs and then didn’t see the water stream when I cranked the engine I shut the engine off. It’s a boat so there’s always something.

When you first start the engine you may not see the tell tale water immediately. The water needs to be pulled up the water tube and start filling the water jackets before you will see water.I don't own a 200 hp so I can't advise as to how long it takes from initial start to seeing the tell tale discharging water. The next time you launch, time it, start the engine and watch for first signs of water discharge. Use this for your gauge when hose flushing. I always watched the muffs to confirm water was being pulled up. With the muffs attached to the lower unit both sides of water pickup screens covered. Turn the water on make sure the muffs didn't move when the water pressure was applied. Look at the amount of water coming out around the muffs. Start the engine now look at the water coming out around the muffs. If the pump is pulling the water in you should see a difference in the amount of water coming out around the muffs (less). If you do then you know the pump is pulling the water in and it is being lubricated the impeller blades and pumping water. If there is no change and the same amount of water is flowing out around the muffs shut the engine down immediately. If there are no lower water pick up screens on the lower unit or you have then blocked correctly the flushing muffs should work. I have used flushing muffs on outboards and stern drives for years. I had an international Dyno that I tested and troubleshot engines with. I would run them at full load using flushing muffs with out issue.


https://youtu.be/4nThSjoBl-4

 

[nboyer]

I've posted in another thread on this topic and shared my observation that when doing a static flush, I do see water coming out of all of the water inlets on the lower unit. I just called Yamaha and asked them about this very question and they confirmed my observations ((866) 894-1626). Yamaha said this is adequate for flushing not only the engine, but also the lower unit. However, Yamaha did mention do not attempt to run the engine with a hose attached to the flush port. My personal view is that static flushing is sufficient to flush the entire engine, to include the lower unit. If you have any questions, you should give Yamaha a call, after all, they were the ones who manufactured the engine and should know best. Cheers! -Norm

 

[scross]

Just curious. Doesn’t anyone use the clean plastic garbage can filled with water up to the waterline around the outboard shaft and a high pressure hose to keep the garbage can full anymore? Did that with my 25 hp outboard all the time and never had any issues. Are these outboards way too high up for that method?

https://m.youtube.com/watch?v=d56-vQ2xy6wn

 

[Capt’nKarl]

Thanks Norm and all the others who contributed to this conundrum. I guess I’ll convert to being a static flusher.
Cheers to all,
Karl

 

[tjiann]

This is the text copied/pasted right out of Yamaha's Maintenance Matters publication for their engines which comes with the F200 Outboards:

How do I go about flushing my outboard?
Use one of these three basic methods to flush after each trip.

• Use the built-in flush attachment. This is a great procedure to follow, especially if
you can’t remove your boat from the water, or if your outboard has dual water inlets
and you don’t have the special adapter. Simply connect a garden hose to the inlet
side of your non-running outboard’s built-in flush attachment, turn the spigot on full
blast, and let the hose’s water pressure do the work. Let the water run for 15 minutes
to ensure it fully circulates through the entire cooling system several times. If your
boat’s out of the water, like on a trailer or a lift, the fresh water will also trickle down
and adequately clean the water pump and the lower unit’s cooling water passages.

• The flush muff method. This is the most common and often-used fresh water
flushing method. Simply connect a garden hose to clean fresh water on one end
and a “flush muff” attachment, which slides around the lower unit to provide water
to both sides of the raw water inlet, to the other end. Turn on the water until you
see water squirting out the sides of the flush muff, then start your outboard in
neutral. Set the outboard to no more than a fast idle (900-RPM max) and allow to
run for 15 minutes in neutral. Increase hose water pressure enough to maintain a
bit of squirting out from under the flush muffs at all times while the outboard is
running. This helps ensure it gets fed enough cooling water.
Note: Outboards utilizing two cooling water inlets require a special adapter to use this method. Check with your
outboard’s manufacturer.
Note: Increasing engine speed may cause water demand to exceed supply. If you notice the hose becoming flat while
the outboard is running using this procedure, increase the water flow and/or decrease the engine RPM.
Warning: For safety, we suggest you remove the propeller before you begin. Accidental engagement of the outboard
into gear with the outboard running will cause an exposed propeller to spin rapidly, possibly resulting in serious
injury or death.

• The flush bag method. This method can be used for a boat on a trailer or when
moored.
A flush bag, when filled with water, simulates the outboard idling in its
normal state but immerses the lower unit in fresh, clean tap water. Simply place
the bag around the outboard, attach the hose, and fill the bag. Ensure the water
level reaches the height of the outboard’s water pump (about 1” above the lower
unit separation seam). Start the engine, and run for 15 minutes in neutral. Leave the hose running during this entire procedure. When complete, stop the outboard,
then the hose, and then drain the bag

 

[Rocky Lou]

I've owned Yamaha OBs for many years in salt water only. I only do static flush but I use Salt Away and, unlike what their instructions say, don't run the engine. I do quite a long fresh water flush after 30 seconds of Salt Away. When I see how ineffective hosing the cowlings is to get fully rid of salt, I feel it's necessary. If I run salt away on the cowlings, using the leftovers, then rinse, I find almost no salt remaining before I put on the engine covers.