HELP. Overheat issue??

[123indyrt]

I believe I sucked up weeds. Continuous alarm. Shut it off, wait, start, idle then go for a min or so (I could get further at a lower rpm) then it got to a point I could only go a little at slow speed and the alarm would sound. Went home.. flushed w water for a min (engine off) then put 100psi on the hose

Lake test.. same

 

[henryb]

Check the impeller for debris. If nothing then check if the pisser valve is is putting out water (usually on the rear transom)… should be outputting a constant stream of water. If no water combing from it, then your engine is not getting cooling.

 

[123indyrt]

Check the impeller for debris. If nothing then check if the pisser valve is is putting out water (usually on the rear transom)… should be outputting a constant stream of water. If no water combing from it, then your engine is not getting cooling.

Pisser was clogged. It's worked for a while. Alarm again. I brought a wire.. it seemed clear w warm water coming out. If I stayed medium on the throttle, it was OK. When I would throttle up, boom.. alarm

 

[123indyrt]

Pisser was clogged. It's worked for a while. Alarm again. I brought a wire.. it seemed clear w warm water coming out. If I stayed medium on the throttle, it was OK. When I would throttle up, boom.. alarm

I even put 100psi air backwasds thru the motor from the top of the head

 

[henryb]

Looks like this is the problem, just need to trace it back best you can, remove hoses and try to find where the clog is located… air may not be able to free it up?

 

[123indyrt]

Put water in the pisser hose and use 100 psi air to blow it back. 75% of the ride. Perfect. Wasn't full rip.. alarm. Waiter a few minz, 60% throttle back.. no issues.

Are these boats very sensitive to weeds!??

 

[Tim75]

Put water in the pisser hose and use 100 psi air to blow it back. 75% of the ride. Perfect. Wasn't full rip.. alarm. Waiter a few minz, 60% throttle back.. no issues.

Are these boats very sensitive to weeds!??

Weeds.
The enemy of every jet boat. They clog the intake like a cork. Reduces thrust to near zero. Reduced thrust because of reduced water flow. Which is also your cooling water. Yes, your engine can overheat. One thing that can happen during overheat (if you still have oil injection) is the oil pump shaft seizing in its housing which in turn shreds the pump drive gear. Your cooling water comes thru the 5 small holes in the wear ring.

Has your wear ring ever been removed? There is an o-ring that fits in a pocket that serves as gasket between 2 castings. If that o-ring is missing or the wrong size, you may not be getting as much cooling water as you should have.

 

[123indyrt]

Weeds.
The enemy of every jet boat. They clog the intake like a cork. Reduces thrust to near zero. Reduced thrust because of reduced water flow. Which is also your cooling water. Yes, your engine can overheat. One thing that can happen during overheat (if you still have oil injection) is the oil pump shaft seizing in its housing which in turn shreds the pump drive gear. Your cooling water comes thru the 5 small holes in the wear ring.

Has your wear ring ever been removed? There is an o-ring that fits in a pocket that serves as gasket between 2 castings. If that o-ring is missing or the wrong size, you may not be getting as much cooling water as you should have.

Good info. I've replaced wear rings on older models. I don't think they feed like this one.
Somehow, it seems better. Alarm only came on during the last leg of my day.. I ronically, same place it did the first time.. in chop whilst rippin. I wonder if, under heavy throttle and a chop, if I am getting an air pocket

 

[POPPS]

What boat is this?model?..some pumps,,,seadoos,,,where the cooling intake goes through a hose at the top of the pump have a filter in the pump.,,if it does not have it,,. run water through it,,,you will able to see water leaking at the"O"ring at the transom.

 

[123indyrt]

Well, I can't be 110% certain bcuz I do go in canals.. But.. it may be a sensitive low fuel alarm. I never fill the boat w fuel. By the end of the day, I'm a bit over 1/4 tank. Ironically, the issue got worse thru the end of the day.. yet, never repeated when I went back out (with...more fuel) I'll have to top it off and see what happens..

 

[ToothMechanic]

Well, I can't be 110% certain bcuz I do go in canals.. But.. it may be a sensitive low fuel alarm. I never fill the boat w fuel. By the end of the day, I'm a bit over 1/4 tank. Ironically, the issue got worse thru the end of the day.. yet, never repeated when I went back out (with...more fuel) I'll have to top it off and see what happens..

It’s funny that you mention this.
We have been having the same issue with our Challenger 2000 with Mercury M2 240EFI.
We got a steady alarm on our way in after a nice ride. I shut the boat off, turned it back on and we made it back to the ramp only for the alarm to come back on just as we were pulling into the dock.

I took the boat home, plugged a hose into the boat and ran water for 10 minutes, like the owners manual said. The whole time the hose was on the boat, I never saw water come out of the “pisser hole”/ tell tale and it scared the crap out of me. I thought we definitely had a plugged engine cooling line.

I found some other forums saying that some of these Mercury engines have low fuel alarms, so I went ahead and filled the tank all the way up. I have a 40 gallon tank and I only put 25 gallons into it.

I took the boat up to the launch, turned it on and had zero issues: I inspected the pisser hole/ tell tale and water was flowing out of it steadily.
We took the boat out and cruised around for at least 90 mins.

So, my theory is that the fuel float/ gas tank sensor is either going bad or is bad. I haven’t done the homework to explore this further, but my gas gauge has ironically stopped working. But having 15 out of 40 gallons of gasoline in the tank should not (in my mind) trigger an alarm.

 

[cbjustDOOit]

there is not enough pressure on the hose to make the tell tail work.
I have had 3 of these with the 240efi... none of them shot water out the tell tail on a hose.

 

[Tim75]

there is not enough pressure on the hose to make the tell tail work.
I have had 3 of these with the 240efi... none of them shot water out the tell tail on a hose.

Unless you have a 5/8 or 3/4 ID hose, you will not get enough flow to show anything at the pee hole. Any restrictions, like in-line valves, quick disconnects, long hose runs will block enough flow to keep the pee hole from peeing.

Fuel tank: Keep it full. You will have fewer issues with water. The more air volume in the tank, the more the tank can "breathe" and "inhale" moisture-laden air. Especially at night.