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Correct lines for valves or to pinch off when being towed.

Ericd

Jet Boat Junkie
Messages
241
Reaction score
311
Points
137
Location
Illinois/Florida
Boat Make
Yamaha
Year
2021
Boat Model
FSH Sport
Boat Length
21
Thought I would ask—just in case I might have to be towed sometime. Pictures show the back wall of the 210 FSH engine compartment.

I believe for each engine the main cooling intake line comes thru the wall below the red line, which appears to go the wash ports on the rear deck. These two line meet at a “y” junction and run to the engine. The main line is covered with a plastic ribbed protective cover — my guess it to reduce wear thru the wall.

If I am correct so far, my guess is I would pinch off the lower black hoses if I were being towed. What about the ribbed covering? Get it out of the way? Couldn’t tell if it was simply split and easily removed or not.

Also appears to be a difficult place to access to install valves on those hoses.

Appreciate your comments/help.
3EEDA15B-8744-41A0-BE26-A77903896B4C.jpeg
 
Yes the black lines are the ones to pinch off if you are being towed. The gator skin covering should be split so you would just open it up enough to put a clamp on the line.

You are correct! That would be a tough place to work in. One poster on here removed the cooling water from the Y fitting and put a splice in the cooling water inlet line and attached a piece of hose that he attached to a valve, then ran the other side of the valve via another piece of hose to the Y fitting. He sort of made a loop of line that made life much easier to put a valve in line.
 
Thanks for confirming! Definitely difficult to access!
 
Thanks for confirming! Definitely difficult to access!

Did / have seen the plastic pinch off valves that are on ebay? I bought two, I think they are $8 each.
 
Thanks for confirming! Definitely difficult to access!
And in the 18 years of Yamaha jet boating....I've never had to do this. I do keep a pair of hose clamp pliers (plastic ones) in the boat just in case.....and I'll stand on my head if needed to apply them......but very low probability......
 
I recall seeing a couple valve installations. One was brass and the other a plastic valve. One was probably yours. ?
 
I was just wondering about this the other day... "what if". Don't have a clue which is which but suspect losing one engine would be the most likely scenario. Almost happened once when couldn't get plastic bag of some sort out of the screw and was getting over heat warning.
 
A plastic bag could happen to any one at any time on the water. Knowing how to clamp off the water seems akin to knowing how to change a prop in the water. A smart person would test this before it happens.

An off season project of mine is changing the toolbox that was setup for an IO to being setup for a jetboat. From what I've read hear, you can't have too many ways to clear the pump on the water also.

Tom
 
Newbie question - What is the problem with being towed ? Why do you need to clamp off these lines?
Maybe I need to ask dealer which lines to clamp when I get my boat so I could mark them
 
And in the 18 years of Yamaha jet boating....I've never had to do this. I do keep a pair of hose clamp pliers (plastic ones) in the boat just in case.....and I'll stand on my head if needed to apply them......but very low probability......
What size plastic hose clamps do you have ?
 
If you were adding valves, You can put the valves below the rear hatch, where they are accessible by your access port. For reasons, in my situation, it's not feasible to flush out of the water every time, so I have installed and use the valves to flush the engine with a hose while in the water. I can also get the boat on plane with a single engine, It was useful that one time when I needed it.
 
A plastic bag could happen to any one at any time on the water. Knowing how to clamp off the water seems akin to knowing how to change a prop in the water. A smart person would test this before it happens.

Tom

The bag was jammed between the blade and nozzle… was a mother****** to say the least. However I also have a trolling motor setup from hell so was not worried. Then again, we run around without clamping with the trolling motor, so what’s the difference?
 
 
. Then again, we run around without clamping with the trolling motor, so what’s the difference?

Cooling water is fed by the pump pressure, via an inlet in the pump body. If you build up enough pressure, say going FAST while the engine is off, you could end up feeding water to the exhaust, since there is no engine back pressure. Same as having the hose ON for flushing while engine is NOT running.

At low speeds it's not enough water, but faster, for long enough, you could get water in the engine. So the difference is SPEED.
 
I knew the mechanism but not the exact condition. Think I max out at 10-ish or so on the trolling motor... and even that's rare.
 
I like the plastic ones as they won't rust and I can leave them in the boat on the carpet with no worries (they lay by my batteries with my other tools).
Agree, but I have a broke a few in my days as a mechanic, specifically the sliding sleeve. But as you have said, hopefully the need never arises.
 
Hopefully never an issue but if you leave the throttle lever in forward I think there is even less of a chance of water ingestion at low speeds, as the water can exit the back of the pump, vs build additional pressure with the reverse gate down.
 
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