R-27/OB F300 back-flushing and flying snake-like hose

[baz]

Subject: R-27/OB F300 back-flushing and flying snake-like hose

This subject was not meant to be a 'bait switch' :lol:

Yesterday I ran my engine for back flushing and had the hose attached to the back flush receptacle and had proceeded to run the water from the hose's shore faucet. All went well with seeing the engine peeing so then started chatting with some dock friends.

I normally allow the back flush to run for 5 to 10 mins while I'm doing other things.

This time I was suddenly alerted to the hose end attached to the engine flying up into air, whacking everything within its reach, spraying water everywhere including me and friends and the boat.... what the heck... 😱 :x

I raced over to the engine and secured the flying snake-like hose end only to discover the barbed plastic tube that fits into the rubber hose of the engine's back flush had pushed out allowing the hose end to fly about uncontrollably.

Upon inspection I noted the barbed end is secured to the inside of the engine's rubber tube with nothing more than a nylon zip tie. Obviously, the water pressure or the back pressure from inside the engine was sufficient to force the barbed tube to be ejected and that the nylon zip tie simply was insufficient for securing the barbed tube.

I've back flushed my engine many times and this was a 'first'.

Thank goodness the barbed tube was secured by the hose end attachment so it was not flung to the deep dark waters.

I will be replacing this nylon zip tie with double clamps for sure to avoid this problem from occurring. I consider it to be a safety issue as an adult or a small child could be harmed with the forceful whipping snaking hose end action with its metal end, and could with the force take an eye out or smash teeth in easily.

I will be sending feedback to Yamaha about this issue as well.

 

[Maggie Anne]

I just had this happen to me also, same scenario with hose whipping around the dock (our marina has strong water pressure). I was also worried that it might come off while underway and cause an engine overheat issue.

 

[TomFin]

Knowing how strong the water pressure is at Port of Edmonds I wonder if there is a point at which shooting high pressure water into the engine could cause damage or get water somewhere it isn't supposed to be? Maybe a weak link at the hose connection provides some protection?

 

[Larry H]

RV stores sell an inline pressure reducing valve that can be attached to the hose to limit pressure to under 40 lbs.

 

[baz]

Yes, the Edmonds Marina's doc shore water supply is quite likely high and contributes to this issue. However, as I mentioned I've back flushed several time over past year without this issue occurring.... so what was different this time ?

The nylon zip tie to me is simply not suitable for securing the barbed plastic tube and I will address that for sure to make it more secure.

Not sure if high pressure water into the engine is going to cause a problem or not.... but caution about this is noted... thanks.

I wonder if others with the F300 engine can say if they also see a nylon zip tie being used. I will be seeing another R-27/OB this weekend so will inspect it if it has the Yamaha F300.

 

[Larry H]

Barry,

If that fitting in on the end of a hose inside the motor cover, what does the other end connect to, and does it also use a zip tie? Have you checked the owners manual about flushing to see if there is a pressure limit?

It's possible that there was a pressure surge in the marina water line caused by someone else turning on and off the water.

That hose may have been working it's way off the fitting for a while now, till it finally let loose.