Question about where I mounted exhaust cooling cut-off valve

[JPass]

So I installed a valve that enables me to stop the flow of water to the exhaust in the event I ever have the boat towed or if I have to return on a single engine (2012 210SE twin 155s).

I installed the valves where the manual stated here:


RCGuy was asking where to install the valve on his 215hp SC Challenger 180 in another thread. I started to search to see what I could find to help him out, then I came across this thread http://www.seadooforum.com/showthread.php?78885-Pinch-off-hose-for-towing-in-water where the OP was looking to install the valve exactly where I placed mine (and where the manual seems to reference as well).

The 3rd post says this is not the correct spot for the valve.

Now I am completely confused. Is my valve installed correctly or do I need to move it to the thicker hose that goes to the front underside of the exhaust manifold? Here's where they are currently installed:



I'd just like to confirm the proper valve placement.

 

[rcguy]

My Sea-Doo 2008 Operator's Guide states on page 86 and I quote, "When towing your Sports Boats in water, pinch the water supply hose from the impeller housing to the exhaust manifold with a large hose pincher (P/N) 529 032 500)." On page 87 they continue a new paragraph with a picture of the hose (not too clear) which states, "This will prevent the exhaust system from filling which may lead to water being injected into and filling the engine. Without the engine running there isn't any exhaust pressure to carry the water out the exhaust."

That's all pretty clear not to tow your boat without a hose pincher or a shut off valve. I have the hose pincher but a inline valve would be easier.

JPas, your inline valve is most likely on the right hose since you already had a problem with one engine and no hydro lock. My guide also states to stay well below a maximum towing speed of 24 km/h (15 mph) if you don't have a hose pincher.

 

[JPass]

That makes plenty of sense, but going by the pic in the manual I posted above, it's the hose where I currently have my valves installed. I see the thicker hoses that are located under the manifold and connect to the forward underside of the manifold, but that's not where mine are currently installed, nor where the pic from the manual shows. I just want to confirm. If I have to go get 2 new, bigger valves, no bg deal. I just want it right.

 

[rcguy]

It seems simple enough. It is the hose from the impeller box to the manifold.

 

[Sportster-2001-951C-Stock]

Either location will stop water from flooding the exhaust system b/c both will block water from exiting the manifold log and injecting into the exhaust (which will fill the coaxial space of the exhaust log with water.

The exhaust log is simply a water jacketed exhaust manifold, the bottom (outlet) hose is a drain to overboard and top outlet hose flows injection water into exhaust.

So you can place the valve on the log inlet or log top outlet, either way keeps water from being injected into the exhaust.

 

[JPass]

Either location will stop water from flooding the exhaust system b/c both will block water from exiting the manifold log and injecting into the exhaust (which will fill the coaxial space of the exhaust log with water.

The exhaust log is simply a water jacketed exhaust manifold, the bottom (outlet) hose is a drain to overboard and top outlet hose flows injection water into exhaust.

So you can place the valve on the log inlet or log top outlet, either way keeps water from being injected into the exhaust.

Thanks for clarifying. I thought the manual pic and my valve placement were the same and also correct. I was about to go get larger valves and add them to the larger lines coming straight off the transom just to be safe, but really couldn't understand how their current placement could be incorrect based on the pics from the manual.

Where does the bottom manifold drain to overboard?

Not sure I completely understand the exhaust cooling system flow and the hose routing correctly. Let me see if I have this right.

Water comes in from the pump and enters the exhaust manifold from the forward underside exhaust manifold inlet. It then makes it's way through the cooling lines cast into the manifold, then exits via the hose coming out the top of the rear of the manifold where it then cools the coupling area at the end of the manifold and some of this water is also teed off to the muffler as well (blue lines in diagram). The green line is the hose hookup line that sends water through the manifold (basically taking up the duty of the lower forward exhaust inlet hose that is normally supplied from the pump when the boat is under power (green line). Is this correct?



So what closing the valve does, is it prevents water from being pushed into the exhaust coupling and/or muffler preventing water from back filling the exhaust system and eventually forcing water up through the exhaust to the cylinder head and eventually dumping into the cylinders causing hydrolock. Correct?

 

[Sportster-2001-951C-Stock]

Yep, you got it. I drew some arrows showing the direction of water flow. Not all of the heated water is injected into the exhaust just aft of the manifold log, a good deal of the heated water goes overboard out the reverse flush port (your hose connects here for reverse flush cooling and to hopefully remove sand and debris that might have settled in the manifold and jet pump pressure supply tap).

I think the way you installed the valves looks very good, one thing you might watch for is lack of water at low speed due to the hose was moved higher. Note the hose goes up before going back down to the two injection locations. This is an upside down p-trap that allows air trapped in the exhaust log to purge out and also due to the height keeps water from siphoning from the manifold and filling the exhaust while engine is off.

The additional height of this upside down p-trap due to installing the valve and raising slightly the overall height MIGHT (slight might) alter the quantity of cooling water injecting while at low speed. This would be my only concern to watch for, just monitor the exhaust temp while idling and make sure it doesn't begin overheating.

If there is a new cooling problem at low speed, reconfigure the hose so that upside down p-trap is back at original height.

I think you're good to go.

 

[JPass]

Awesome man thanks. I believe the body of the valve is about 1", so the height of the P trap is about an inch higher. I could always remove the extra hose to bring it back to the normal height. I've had them on for a few months and so far no issues. Temps never exceed 189 degrees. Being that we purchased the boat in August, we've been through the hottest times and water temps of the year down here in sunny Florida. No issues as of yet.

Wish these things ran cooler than 189, but I guess that's how Sea Doo intended it. Our previous boat ran about 140 all day long.

 

[pete63]

That makes plenty of sense, but going by the pic in the manual I posted above, it's the hose where I currently have my valves installed. I see the thicker hoses that are located under the manifold and connect to the forward underside of the manifold, but that's not where mine are currently installed, nor where the pic from the manual shows. I just want to confirm. If I have to go get 2 new, bigger valves, no bg deal. I just want it right.

i certainly wouldn't install there, call me old fashion! i would do as per the manual and as rcguy says.
i would have thought, you shut the water off before the manifold!? at least it minimizes any other protential risks. i have had pin hole leaks from the water jacket etc.

 

[JPass]

i certainly wouldn't install there, call me old fashion! i would do as per the manual and as rcguy says.
i would have thought, you shut the water off before the manifold!? at least it minimizes any other protential risks. i have had pin hole leaks from the water jacket etc.

The pic posted in my first post shows exactly where the manual shows to pinch the line for towing. Not sure if there's a difference between 2008 and 2012 manuals, but page 86 in my manual references the intercooler system and mentions nothing about towing. I posted the pic and wording for where to pinch for towing straight from the manual for my year boat.

I could always add second valves coming out of the transom from the pump just for added safety. One of the benefits of having the valves where I've placed them is that they are easy to spot when opening the engine cover during my pre-flight inspections. I would think the chances of someone forgetting to re-open the valve and damaging their motor is greater than the risks of a pin hole leak in a manifold back filling the entire exhaust system on the extremely rare occasion when being towed in.

Hopefully I never find out.

 

[Sportster-2001-951C-Stock]

If there's a pinhole leak in the internal manifold, you're likely to find water in the cylinder after shutting down for a period of time, this creates a hydrolock when the exhaust valve opens during cranking and possibly water in the oil depending on circumstances.

Periodically, disconnect all three hoses from the exhaust log and pressurize the log with 10psi of air and a gauge, watch for pressure decay to determine if the manifold should be replaced. Probably the service manual describes this process?

FWIW, generally in case of mercruisers I find 5~7 years in salt is approaching the limit of manifold life, in fresh they last a very long time, a couple decades isn't uncommon.

Whenever replacing a motor I always pressure check the exhaust logs!!!

 

[pete63]

in the manual, its under special procedures. another reason to pinch here is that its the same for intercooler and na engines. thats what the manual says.
i have 2004 and 2010 manual both say the same thing and have the same picture of the pinched hose.
below i have zoomed in on the piched hose near the carbon seal.

 

[Sportster-2001-951C-Stock]

So basically, depending on which manual you reference, either location is specified? That's the way I understand this and agree.

 

[ZRX Guy]

Is that valve during open operation, passing the hot or cold water at that point? I ask, because was wondering if you could put a CPVC ball valve. If it's the water passing after the exhaust, it'd probably be hot and I don't think I'd wanna do that. For the salt water guys, how often are you inspecting that metal valve for corrosion?

 

[JPass]

If you're going to go with PVC, you'd be better off putting the valve in-line prior to entering the exhaust manifold. I placed mine where I did mainly for ease of inspection. I do close and open the valve on occasion to ensure everything is working properly. So long as you properly flush your motor after salt water use, I don't see any issues with corrosion.

The valves were pretty cheap, so even if I had to replace periodically, I don't see any issues.

 

[Sportster-2001-951C-Stock]

Some of the older skis/boats aren't plumbed quite the same as JPass' later model so beware to study the plumbing carefully, you may have to valve off the water coming from the jet pump instead.

Heat generally isn't a problem with plastic in the cooling system unless something fouls the cooling system then you'll be glad to have a sturdier material. Get real marine quality fittings in case you're concerned about corrosion maintenance.

A marine alloy bronze will be the most trouble-free. There are marine plastic types which are very tough as well, West Marine should be able to help.
http://www.proboat.com/2012/07/beware-the-brass/

 

[ID62]

Hi JPass,
It's the wrong place for the 155 HP engine. The upper hose and the lower hose goes directly into the J-Pipe. It's different for the intercooler and super charged engines. But at your current place you are still not sure that your engine get flooded. Upper and lower hose goes from the exhaust manifold into the J-Pipe. From the top of the J-Pipe there is another hose which goes to back of the boat. From this hose you can cool the exhaust pipes when the boat is on the trailer. But once the exhaust cooling system is pressurized from the jet-pump, this hose from top of the J-Pipe can only releases a too high pressure. The only correct hose is as rcguy wrote, the hose which comes from the impeller box. Look inside the BRP spare parts pages and check out the cooling system.

 

[Sportster-2001-951C-Stock]

The only correct hose is as rcguy wrote, the hose which comes from the impeller box.

Do you see this hose shown in this drawing attached in red color that clearly goes directly overboard from the lower manifold? 2012 210 Challanger SE 2x215 ?

http://partsfinder.onlinemicrofiche...make=seadoojb&a=199&b=2&c=0&d=-COOLING-SYSTEM

 

[JPass]

Hi JPass,
It's the wrong place for the 155 HP engine. The upper hose and the lower hose goes directly into the J-Pipe. It's different for the intercooler and super charged engines. But at your current place you are still not sure that your engine get flooded. Upper and lower hose goes from the exhaust manifold into the J-Pipe. From the top of the J-Pipe there is another hose which goes to back of the boat. From this hose you can cool the exhaust pipes when the boat is on the trailer. But once the exhaust cooling system is pressurized from the jet-pump, this hose from top of the J-Pipe can only releases a too high pressure. The only correct hose is as rcguy wrote, the hose which comes from the impeller box. Look inside the BRP spare parts pages and check out the cooling system.

See post #7 that shows water flow from the pump, through the manifold, exhaust, and then out the rear. I'm fairly certain my valve location is just fine. While having the valve straight off the pump prior to the exhaust manifold is ideal, my location is fine and way more visible. The only issue that can happen is the chance of water leakage into the cylinders through a leaky exhaust manifold...........which would be a problem regardless of the motor running or not. For the hopefully rare occasions I'd need to motor back on one engine, I'm perfectly happy with my valve placement.

 

[ID62]

OK, I just saw it. The cooling system has been changed and there isn't a J-pipe anymore.....
I have a 2006 model with the 155s and there it's totally different. So you are right, this is also working.

 

[rcookr1]

So I installed a valve that enables me to stop the flow of water to the exhaust in the event I ever have the boat towed or if I have to return on a single engine (2012 210SE twin 155s).

I installed the valves where the manual stated here:
View attachment 34072

RCGuy was asking where to install the valve on his 215hp SC Challenger 180 in another thread. I started to search to see what I could find to help him out, then I came across this thread http://www.seadooforum.com/showthread.php?78885-Pinch-off-hose-for-towing-in-water where the OP was looking to install the valve exactly where I placed mine (and where the manual seems to reference as well).

The 3rd post says this is not the correct spot for the valve.

Now I am completely confused. Is my valve installed correctly or do I need to move it to the thicker hose that goes to the front underside of the exhaust manifold? Here's where they are currently installed:

View attachment 34073

I'd just like to confirm the proper valve placement.

In you picture the valve is handle is straight up if that's the open position? I would turn the valve assembly 180 so the handle would be down in the on position.

 

[JPass]

In you picture the valve is handle is straight up if that's the open position? I would turn the valve assembly 180 so the handle would be down in the on position.

The handle turns 90 degrees clockwise. When the handle is in line with the valve body (12 o'clock), it is open. When the handle is pointing to 3 o'clock, perpendicular to the valve body, it is closed.