Flushing 2019 115hp Yamaha 4 stroke

[mark960]

I have a Worldcat catamaran with twin 2019 Yamaha 115hp 4 stroke engines. Accessing the flush fittings is very difficult while the boat is in the water. I am hoping to setup a system where I can attach the hose inside the back of the boat to flush the engines. I have seen this done on other boats, and even seen kits to allow this to be done. My biggest problem is that, even with the cowling removed, I can not find where the existing flush hose goes into the engine. The hose disappears under the engine.

 

[Sea Rider]

Welcome to IBoats,

You're trying to flush the motor from the inside ? what about the external flushing ports those motor must count with ?

Happy Boating​

 

[mark960]

Welcome to IBoats,

You're trying to flush the motor from the inside ? what about the external flushing ports those motor must count with ?

Happy Boating​

Yes, I am trying to flush the motor from a fitting I plan to install IN the boat. Trying to access the flush ports on the motor is difficult to reach from a precarious position at the transom. The problem is I can not find where the flush hose goes into the engine block. It disappears below the engine. Any ideas where this hose may be accessible under the cowling???

 

[boscoe99]

I can understand a flush system that begins in the boat but they all run to the motor. From outside the motor and then into the motor. Using the Yam fitting installed on the outside of the motor.

Are you contemplating drilling new holes into the cowl so as to completely bypass the Yam system so as to go directly to the block?

 

[mark960]

I can understand a flush system that begins in the boat but they all run to the motor. From outside the motor and then into the motor. Using the Yam fitting installed on the outside of the motor.

Are you contemplating drilling new holes into the cowl so as to completely bypass the Yam system so as to go directly to the block?

NO HOLES in the cowl. The hose would pass through the control bundle and then "splice" into the existing system. That way, it looks clean and professional, and the factory flush fittings still work normal.

This youtube video shows how it was done on a different outboard. (OMC??)

 

[boscoe99]

Seems too easy to follow the flush hose from just inside the lower cowling to where it connects with the block but perhaps this road map may help.

 

[boscoe99]

I hope that you realize that as water is being applied to the block, some of it is being lost down and out of the water pump tube and via other ways. The longer the hoses used the less water pressure there will be to the block. The less the pressure the less the water flow. You may be cobbing a system together that will reduce the effectiveness of the flushing procedure.

 

[boscoe99]

 

[99yam40]

well after looking at that above,
I always thought the stats controlled the water flow to the heads for cooling
I must have been wrong

 

[boscoe99]

 

[boscoe99]

well after looking at that above,
I always thought the stats controlled the water flow to the heads for cooling
I must have been wrong

Always remember. All Yams are created equal. Some are just more equal than others.

 

[boscoe99]

well after looking at that above,
I always thought the stats controlled the water flow to the heads for cooling
I must have been wrong

This should make you feel better.

 

[99yam40]

those pesky engineers, they have to change things up just to show they can.

at least I was right on some of the older motors

 

[Sea Rider]

Is it possible to install say a permanent fitting at the external flushing port with a hose that extends to side of transom in which can connect an external water hose at the other extreme for any time flushing ? This will solve the current precausious flushing position at the transom...

Happy Boating​

 

[boscoe99]

Is it possible to install say a permanent fitting at the external flushing port with a hose that extends to side of transom in which can connect an external water hose at the other extreme for any time flushing ? This will solve the current precausious flushing position at the transom...

Happy Boating​

That is the typical way that I have seen it done.