Overheating help

[Hike]

I received an overheating warning on my port engine as it went into 3000rpm safety mode yesterday at the end of a full day on the water. I shut down for a while to cool then it was fine on way home.

I noticed I have water coming out of 3 pee holes except the Port Exhaust port (most forward hole).
I snaked a wire through the port exhaust pee hole about 4 feet in. Didn't feel any obstructions but when I pulled out the wire, there was some oil on it. Is this normal? Starboard pee hole was clean.

Do you guys keep a hose line pinch clamp onboard incase you need to come home on one engine and not hydro-lock? I'm starting to think that would be a good idea. Wondering what tool you guys use to clamp the Y hose at the back of the engine compartment.

Thanks for the help!

 

[Scottintexas]

You should not have any indication of oil in any of the water exit lines,

I would disconnect that indicator hose at the engine to see if there's indication of oil there also,

You should watch Buckbuck's video in the FAQ section of "how the cooling water flows" and if you don't have tow/flush valves installed have some sort of radiator/hose clamps or straight vice grips to clamp off your cooling inlet line,


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[Hike]

Thanks @Scottintexas
Is it normal to not have the port exhaust pee hole shooting water? I don't recall ever seeing that port working. I'll try to disconnect that line where it meets the large hose by the engine. I'm a bit intimidated by those constant pressure hose clamps!

 

[Scottintexas]

If you're on the water and the engine is above 4K rpm you should definitely see water through both holes and especially if you're above 7k rpms,

if you're at home on the hose most members don't see any water from the indicator holes.

It would probably be good to trace the hole that is not working from the hull fitting back into the engine compartment, I would hate to try to diagnose it only to find out yours are hooked up in reverse of the norm in buckbuck's video,

When I'm driving it's every so often looking over the side to confirm I see 4 cooling streams and no bilge action,

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[Hike]

The port exhaust pee hole that isn't working does indeed lead back to the port engine.
What would cause the oily residue inside that line?
Should I stop driving the boat even though the temp alarm hasn't come back?

 

[WREKS]

What would cause the oily residue inside that line?

What does the oil look like when you check it at the dipstick? How does it compare to the oil on the starboard side?

 

[Scottintexas]

If your oil level and consistency looks ok, I wouldn't hesitate to drive the boat, it's been like this for how long ???

It is something I would want to figure out if I had time before my next trip, I might even be tempted to pull that whole line or maybe disconnect it and run some water through it from the hose and try to catch it (maybe a funnel on the hull and catch it in a bottle at the engine connect) to confirm it's clear and see if there's any (or how much) oil is mixed in.


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[Hike]

Oil looks good for both engines. I took off the port and starboard lines fro the engine that lead to the exhaust pee hole. Both hoses look the same where they attach to engine, not really oily just some black dirt (see photo). I can blow through the starboard but not the port hose. Going to try and blow it out with a garden hose.

 

[Scottintexas]

I might even try to feed a cleaning line through it from the engine to see if I can tell where it stops, that hose is soft you may be able to squeeze and break it up with your fingers,

If you do use a water hose/air compressor be aware what's next to your boat, a few members have reported when the clog finally lets loose it a putrid mess coming out the side of the boat,


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[WREKS]

I can blow through the starboard but not the port hose. Going to try and blow it out with a garden hose.

When you snaked in the wire you may have just pushed the plug deeper. Low pressure compressed air may blow it out. Just disconnect the line at the rubber joint between the exhaust pipes, so you do not blow it into your exhaust system.

 

[WREKS]

My overheats have been caused by thinking I could run the engines in shallow water (less than 3'). I blocked up the water jackets with sediment. Hopefully you do not have that problem.

 

[Hike]

Problem solved! It was some small pieces of plastic clogging the pee hole. I blew on the hose with my mouth from the engine side and must have pushed them out the port just enough to grab them by hand. Then I attached a garden hose with a yamaha water flush fitting attachment and made sure that sucker was clean. I've got 4 pee holes working now.

So the question I still have is, would a clogged pee hole be enough to throw a High Temp warning?

 

[Scottintexas]

So the question I still have is, would a clogged pee hole be enough to throw a High Temp warning?

Absolutely NOT, the holes are only indicators to show you what's happening,

You probably either had debris in your pump or over the intake screen disrupting the cooling water intake, when you stopped it floated away and you were able to drive in without any issues,


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[Scottintexas]

so now that this is solved you need to look at our FAQ tab at the top of the page for "how to block off your cooling line when being towed" or flushing,

also, I'd have to wonder where that piece of plastic came from??? that looks really big
how long have you owned the boat ?

 

[buckbuck]

And how did it make its way to the exhaust indicator line? Hmmmm

 

[Hike]

I've owned the boat for two years. I love it!

The outside of the hose is in good shape but could the debris have come from a deteriorating hose interior? It was very thin plastic or rubber material.

I'll look into installing a shutoff valve.
On the MR-1 would it go here? Is that a 1/2 inch hose?

What's the red hose for?
Thanks

 

[zipper]

Yes, The red hose connects to the flush ports above in the cockpit seating.

 

[tdonoughue]

My guess is that is the remnants of a plastic bag. Probably got sucked onto the intake of the cooling system (triggering the error?) and a small piece of it broke off and into the cooling system or something. Those things are the worst if you suck them up...

 

[Hike]

One other factor I didn’t mention is that for about two hours leading to the overheat warning, I was pulling a 3 person tube aggressively. After reading some more great threads on this forum, I think this could be a common issue. Although I’ve pulled this tube countless times and never had an issue. The pee hole clog could have been unrelated.

https://jetboaters.net/threads/really-weird-issue-need-help-engines-overheating-randomly-yamaha-dealer-says-it’s-not-happening.19141/

 

[Betik]

In theory you should be able to run those engines WOT for hours without overheating them