Yamaha 90

G

Gene&Mary

New member
I have the Yamaha 90. I was washing down the engine using the hose connection and heard a pop like a fitting being blown off of a hose. As I was at the marina where I store the boat and I was having the 20 hour service done, I told the shop about what I had heard. After the service they verified that the barbed fitting had been blown off the rubber hose. They told me that the rubber hose had been clogged with salt and that caused it fitting to be blown off. So a bunch of questions-

1. Is this wash down system a direct part of the cooling system so that if this occurs again without me knowing, will the engine not be cooled sufficiently or at all?

2. Is this connection accessible and visible if I remove the engine cover?

3. I had previously washed the engine down using ear muffs. I had noticed that it took longer that I would have expected for the pee to start. In fact the time before this I got sufficiently concerned that I shut the engine down which is why I used to hose connection for wash down the last time. Would the lack of using the hose connection have caused that little rubber hose to salt up after only 23 hours?

4. What is the best way to wash the engine down, the ear muffs or the hose connection?
 
Gene&Mary":1bb2fkl4 said:
I have the Yamaha 90. I was washing down the engine using the hose connection and heard a pop like a fitting being blown off of a hose. As I was at the marina where I store the boat and I was having the 20 hour service done, I told the shop about what I had heard. After the service they verified that the barbed fitting had been blown off the rubber hose. They told me that the rubber hose had been clogged with salt and that caused it fitting to be blown off. So a bunch of questions-

1. Is this wash down system a direct part of the cooling system so that if this occurs again without me knowing, will the engine not be cooled sufficiently or at all?

2. Is this connection accessible and visible if I remove the engine cover?

3. I had previously washed the engine down using ear muffs. I had noticed that it took longer that I would have expected for the pee to start. In fact the time before this I got sufficiently concerned that I shut the engine down which is why I used to hose connection for wash down the last time. Would the lack of using the hose connection have caused that little rubber hose to salt up after only 23 hours?

4. What is the best way to wash the engine down, the ear muffs or the hose connection?
Click to expand...

I too have a new 90 Yamaha -

The fitting your talking about is on the port side of the motor in front of the tilt switch and you do not need to pull the cover to access it.
I use it to flush with salt away and is is important not to have the motor running while flushing this way.- if it is not connected your motor will not cool and I noticed when screwing the fitting back in you need to make sure the rubber gasket sits flush like a garden hose gasket also make sure the hose isn’t twisted and don’t cross thread (it’s plastic).
I find it hard to believe that salt plugged the hose in only 20 hrs. but who knows???

I use a 100 gallon feed tank filled with water to flush my motor but when I used muffs in the past it didn’t push enough to water to come out the tell tale hole. I was told I needed bigger muffs and possibly more water pressure. I still haven’t tested new muffs yet.

I believe flushing with salt away is best if you use your boat in the ocean and was told by Yamaha that flushing through the flush hose is sufficient but I do both tank and flush hose just to make sure.
Hope that helps!
 
Thanks Teufelshunde.

I haven't been back to my boat yet so my information is from what the marina said but I do know the fitting that came apart was not exposed.The fitting I'm talking about is downstream from that exterior garden hose fitting you are talking about.
 
It has been some years since I have owned a Yamaha 90 (I owned both a 90 and a 115, which I believe is on the same block). If I kept the boat in the water, I used the hose fitting on the side of the engine. If I had the boat out on a trailer I used the muffs. On my 90 I did have issues with some salt plugging up the passages, and when I had them cleaned the mechanics said someone had not let the engine run at lower RPM to cool down. (I was running in brackish water at fast idle for about 30 minutes, so it would have been the previous owner who didn't let it cool down.)

As I recollect the "pee" stream was good when running the engine on the muffs. When you run on the hose fitting, you don't really get full irrigation of the water pump impeller and impeller housing.
 
Gene&Mary, like Teufelshunde, we use a 100 gallon Rubermaid Commercial Stock Tank to flush both the main and kicker after a run in saltwater. Ear muffs for flushing a motor is OK but you should sit with the motor being flushed to ensure that the muffs do not fall off the motor. Using a stock tank is nice because the water outflow from the motor will pour back into the tank. I feel much more relaxed using this type of flush over the ear muff type of flush. I realize that 100 gallons is a lot of water to use for this type of flush especially for those living in water restriction areas. I personally water the grass when draining the tank with the excess water.
Make sure that the water level is above the motor cavitation plate if you use the tank method to ensure that the pump can pick-up the water it needs to run through the motor and flow back into the tank. Yamaha recommends that you flush a motor for atleast 15 minutes after being exposed to saltwater. Gary.
 
Thanks everyone for your comments and good information.

My question was more directed to the design of the hose connected cooling system.
Thru another forum I think when you connect the garden nose to the engine fitting, the water flows thru the small rubber hose to a "Y" fitting that is in-line with the engine cooling system. This allows the wash down water to flow thru the engine cooling system.
When the engine hose fitting is reconnected to the engine, it connects into a blank end which seals the engine cooling system for normal cooling operation.

Is this understand correct?

My question again is if this "Y" fitting blows apart without me knowing it, is the cooling system compromised? will cooling water flow back out of one leg of the "Y" and possibly be seen coming out under the engine cover?

Thanks
 
My Honda BF90D has the flushing port. If the flushing hose is not in the stowed position (i.e. is hanging loose), no water comes out when running the engine normally in the water. There seems to be a check valve in the system.
 
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