Outboard water flow

[rls1936]

During cold weather, my 90hp Mercury outboard has no water flow from the outlet tube (no water stream). I've read that the water stream is just an indicator and that the engine is really cooled by other means. If I wait an hour or two after putting it in the water it unfreezes and works fine.

Can I harm the engine if I run it until it heats up enough to unfreeze the impeller? Right now, I just use my trolling motor with the outboard in the water until it unfreezes.

Thanks.

[FisherMike]

It sounds to me like the tube is just freezing up and the water pump is working. Take the cover off and look at the tube to see if there is a low spot. That would be the point it's freezing at. If that's the case, use a wire tie to raise it up just a little and then check it again. If the impeller was to freeze up, you wouldn't be using it again because you would do damage to the impeller and or the shaft. The pump housing drains it's self out so I doubt it's freezing.

[HOTSPOT]

Always to sure be to drain the engine as best you can right after you pull her out of the water.

I tilt my engine completely down and crank it up, then let it run for 5 seconds.

Another trick is to keep some of those disposable hand warmers handy and use them to thaw the pee tube.

[slabbandit]

Hey there rls1936,

No water coming out of your tube is usually a sign of problems with your water pump. Some of the problems I've had in the past have been dirt dobbers stopping up the tube itself to as serious as all but one fin being broken off of the impeller. It is a good idea to change the impeller out every couple of years depending on usage.

One year my stream was coming out fine while running but appeared to be sputtering while at idle. I thought I just had a rough idle but I would get an overheat warning at top speed. Slowed down a little and it was fine. Pulled the impeller and found that I only had 1 out of 6 fins left on impeller!

Could be as simple as a little bit of water trapped in your tube and it finally melts free from the engine heat but I sure would make sure you have an overheat warning. Another idea is maybe not run wide open until you see the stream coming out good and strong.

[herb]

If you are getting freezing temps, after you load the boat at the end of the day, let the motor down till it sits verticle. Let all the water drain from the lower unit. No need to start it to get the water out.
When you get home, let the motor down again till verticle if storing outside.
Next time you launch, if in freezing temps or if it froze the night before, let the motor idle a few minutes before taking off up the lake. That's just to let the motor warm up some, not to thaw the "tube". That will happen on it's own after some running time. Sometimes it takes anywhere from 5 minutes to 30 minutes. Don't let it scare you. After 40 years of running in freezing temps, I've yet to have one that didn't thaw out eventually, and never had one hurt from running in the cold. Just take care of it when you load up and you shouldn't have any problems.

[FisherMike]

Take care of the low spot in the tube (if there is one) first. Start with the obvious and easy things first. If there is not a low spot and no water comes out at an idle and you are sure the tube is clear. Change out the impeller.
The impeller is mabe of rubber and after years of use, it gets brittle and the veins will break off or just remain in a rigid state.
Herb, it will be a cold day in h*ll before I let my outboard run from 5 to 30 minutes, not knowing for sure if my water pump is working or not. These motors are water cooled not air cooled and no matter how cold it is out, the motor will overheat without water.
RLS1936's problem does sound like a frozen tube to me, but I'm no expert, but I have replaced somewhere around 30 or so waterpumps on all kinds of outboards.

[rls1936]

Thanks guys, you've been a great help.

[BANDIT]

As long as water is coming out of the exhaust, it is ok. Your tube is just an indicator.

[herb]

Mike, if the water pump worked fine the last time it was used, I certainly would not be afraid to run the next time I wanted to go fishing. Warm weather or cold.
Besides, most of the newer motors will shut down as soon as there is a problem indicating an overheat situation.
Outboards were engineered to run in all weather conditions, including freezing temps. If I had to check for a frozen pee line and run a wire up in it every time I went to the river, I'd never get anything done.
My 4 stroke I treat like a car engine. I start it, and let it warm up a bit before taking off. More times than not this winter my "tube" has been froze. Within 5 minutes after I leave the ramp, it's spraying water.
That motor has to get to operating temperature for the thermostat to open and start circulating water. It won't get there by babying it.

[FisherMike]

I gotta agree with you.
That's why I believe it's his pee tube. The water pump worked prior to that.
I've had that problem before too and thats why I reposisition the tube so it always drains. Just a little insurance for me.
My wife won't let me buy another motor if I goof this one up.