Intake Cooling Line Valves - Good or Bad?

[swatski]

I struggle with this question.

Have been deliberating an install of shut-off valves in the intake lines (for easy shut-off if towed) and water strainers forever. But not sure if it's actually a good idea or not so good - because of flow restrictions. A strainer presents some winterizing issues, too, but nothing that can not be solved simply. For now, I just carry a pair of vise-grips and hope I won't need them, but would like valves and a strainer.

Going from 3/4" to 1/2" restricts the flow by (almost) two fold! That's no joke, particularly at low speeds/RPM when the pump intake pressure is low.

Of course one could replace intake hoses (with larger diameter) to use bigger valve but that could in turn affect the flow rate, which may not be a great thing at low RPM/pressure.

IDK! Curious what other members think.

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[Bill D]

I have the Island Racing valves on my boat and have had no issues with them restricting water flow. My cooling water outlet is generally not as hot as the hot water from my sink, and the pressure / flow looks the same as that of other 242's. I like knowing they're there, but have never had to use them (thankfully).

 

[zipper]

@swatski I would think you could find full port valves for that mod. However the fittings might be the restriction issue. I have been thinking about adding valves to mine. I am not crazy about clamping my hoses with vise grips. When we first got the boat we needed a tow, not gonna discuss it, will just chalk it up to being a new owner and unfamiliar with the boat. The Sheriff's boat towed us back to our marina, where he was docked, Very slowly, good thing as I was unaware of the water intrusion issue until I learned of it later here. The other day I was joking with Willow that I should install the valves. Then I could use it as a tender behind a larger sailboat. I know too heavy to pull around, just one of those pipe dreams.

 

[swatski]

However the fittings might be the restriction issue.

Yep, it is (almost) inevitable, unless one would swap the whole line.
What @Bill D says is encouraging, in a sense that maybe the line fittings are not rate limiting (and something else is - inside the engine/exhaust).
I often think that it would be nice to have strainers, too. But then again - stronger flow through the engine/exhaust may be more useful in the long term.

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[Gym]

I have been running tow valves for 6 seasons now with no issues. I used 1/2 inch full port stainless steel. I use them to flush with Salt Away after every trip as I boat in the ocean. For me their primary use is for flushing while sitting in the salt water. I have not yet needed them for towing or single engine operations. If you are operating in the ocean I hope you don't think you'll get very far on a single engine at the manufacturer's recommend "no wake" speed against a head wind and an outgoing tide. Most fresh water operators can get away with padded jawed vice grips. Us salty dawgs have more uses to justify the valves.

 

[swatski]

I have been running tow valves for 6 seasons now with no issues. I used 1/2 inch full port stainless steel. I use them to flush with Salt Away after every trip as I boat in the ocean. For me their primary use is for flushing while sitting in the salt water. I have not yet needed them for towing or single engine operations. If you are operating in the ocean I hope you don't think you'll get very far on a single engine at the manufacturer's recommend "no wake" speed against a head wind and an outgoing tide. Most fresh water operators can get away with padded jawed vice grips. Us salty dawgs have more uses to justify the valves.

Oh - that totally makes sense!
I did not think of it that way, but now I wonder if one should always close the intakes (w/valves or grips) when flushing the engines. Also on land (on a trailer) - just to force more flow through the engine/exhaust passages.
I guess one would need to double check the valve closes the intake hose before the flushing line connects to it!

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[itsdgm]

I've heard of the shutoff valves. Like you, it seems that since I don't tow the boat on a regular basis, I've chosen to simply keep a set of hose pinching pliers. Make sure that your vice grips are designed like these that have parallel sides. Otherwise you run the risk of leaving an opening in the line that could prove disastrous.

As far as the screen. I haven't seen any kits out there. There is a strainer/screen located on the side of the pump. Is that not enough?

 

[itsdgm]

Oh - that totally makes sense!
I did not think of it that way, but now I wonder if one should always close the intakes (w/valves or grips) when flushing the engines. Also on land (on a trailer) - just to force more flow through the engine/exhaust passages.
I guess one would need to double check the valve closes the intake hose before the flushing line connects to it!

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Part of the reason to flush is to also back flush the water inlet and strainer back in the pump.

 

[swatski]

As far as the screen. I haven't seen any kits out there. There is a strainer/screen located on the side of the pump. Is that not enough?

Yes, I was intrigued by @DiverB 's set up in the boat he just listed, I really like the idea! Apparently also available from @ISLANDRACING as a kit.
http://yamahajetboaters.com/forum/viewtopic.php?f=240&t=66019
and
https://jetboaters.net/threads/chesterfield-michigan-2014-ar240-will-deliever.15411/#post-266320

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[swatski]

There is a strainer/screen located on the side of the pump. Is that not enough?

Part of the reason to flush is to also back flush the water inlet and strainer back in the pump.

I agree with both.
And thanks for the tip on those vise grips. Looks like that is going to be the answer for me for now!

EDIT: "Radiator Hose Pinch-Off Pliers", makes sense! I'll be darned.

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[itsdgm]

Yes, I was intrigued by @DiverB 's set up in the boat he just listed, I really like the idea! Apparently also available from @ISLANDRACING as a kit.
http://yamahajetboaters.com/forum/viewtopic.php?f=240&t=66019
and
https://jetboaters.net/threads/chesterfield-michigan-2014-ar240-will-deliever.15411/#post-266320

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Nice. I haven't seen those strainers before. They look like they would catch a lot of sediment that would pass right through the stock strainer.

 

[Betik]

I am seriously considering this as winter mod. For $200 I think it is worth the trouble.

 

[swatski]

Nice. I haven't seen those strainers before. They look like they would catch a lot of sediment that would pass right through the stock strainer.

True! But those radiator hose grips may be the safest and simplest solution after all. I would worry those strainers could get clogged up with silt, sand and some such throwing an overheat code or worse.

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[J-RAD]

These hose pinchers came recommended on the topic on Facebook:

https://www.amazon.com/gp/aw/d/B0002NYB78/ref=mp_s_a_1_1?ie=UTF8&qid=1505968229&sr=8-1&pi=AC_SX236_SY340_FMwebp_QL65&keywords=hose+pinchers&dpPl=1&dpID=31ku8xwGFtL&ref=plSrch .

Seemed like a simple alternative... inexpensive, easy to use, and easy to carry.

 

[Chip F.]

Thanks for the discussion. I went looking for clamps and found these plastic ones on eBay

 

[Julian]

The primary reason I bought a Yamaha was for the reliability of these engines....so this is one mod I've not seen the need to go to great lengths to install. Locking hose clamps or the small clamps above is all you really need...and will likely never use. In water engine flushing isn't anything I need to do now....so thats not an issue either.

 

[Jgorm]

I'll be installing valves on mine. A ball valve will not have substantial restriction. I bought these for the wave runner. Performance Tool W83205 3-Piece Line Clamp Set https://www.amazon.com/dp/B003WZX7UA/ref=cm_sw_r_cp_apa_-x8WzbFS926SH

 

[swatski]

A ball valve will not have substantial restriction.

You still need to use fittings though, and any decrease in diameter is affecting the flow disproportionately. I've learned that designing a ballast system.

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[zipper]

You still need to use fittings though, and any decrease in diameter is affecting the flow disproportionately. I've learned that designing a ballast system.

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There are existing fittings already in the line for "Y's" and "T's" which already restrict flow. There must be thin wall barbed fittings out of S.S. that will restrict less than a plastic fitting. I use larger versions of these thin wall fittings on my maple sap lines. Every fitting will increase friction and reduce flow. Try to keep the 90 deg fittings to a minimun.

 

[Betik]

can we use a 3/4 to 1inch fitting on both ends and simply put the switch on the 1inch part of the system ?