Starting OB below freezing

Tacklewasher

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Sep 18, 2002
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Went fishing with a friend when the air temp was about -5C. He did something I think is interesting and may have to do.

Going out, we sat for about 10 minutes with the motors in the water before he would try starting them. Apparently, he has torn up an impeller in the past with it being frozen in place. Tried to start right away and he figures there was enough water to hold the impeller in place. Now he leaves them in the water for a bit before starting to let it thaw out.
 

Silvertip

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Re: Starting OB below freezing

If it works, nothing inherently wrong with the technique. Unfrozen water is not a problem.
 

Chris1956

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Re: Starting OB below freezing

TW, If that boat is moored or docked, the motors should be left in the fully down position during freezing conditions, so water in the exhaust hub doesn't freeze and crack the casing. If the boat is trailered, the motor should be left down to allow the motor to drain after use, and to keep rain and snow out of the exhaust hub.

In a nutshell, I am unsure how water was retained in the waterpump, and caused the impeller damage. It should have drained out if he trailered it, with the motor down. If he tilted the motor up while moored or trailering, it still should have drained. If water was retained in the waterpump, I am surprised the waterpump casing was not cracked.
 

steelespike

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Apr 26, 2002
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Re: Starting OB below freezing

Usually if your going to have freezing weather your bretter off with the motors down whether in the water or on a trailer.With the motors tipped up water can be trapped
where it will cause problems like tearing up a impeller.Also there is the possibility of watrer freezing in the leg and causing problems.I guess if your in salt you may not want to leave the motors down.
 

dingbat

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Nov 20, 2001
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Re: Starting OB below freezing

I leave the the dock may a time @ -10 C. I've had the pi$$er freeze on me. I've had the water pressure gauges freeze on me. I've had problems with saltwater freezing in the rod guides and raw water (saltwater) hoses frozen solid. Never had a problem with a frozen water pump impeller.

The way a water is designed with an open intake on the bottom and a vented output on the top, I?m have a hard time believing it?s even possible.
 

Moody Blue

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May 24, 2004
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Re: Starting OB below freezing

Seems like sound advice Tacklewasher. On a similar note, someone once told me never to crank a motor over with the starter motor first thing after being stored for a long period. The impeller can stick to the housing and possibly be damaged. I always slowly turn the motor over by hand 1 or 2 revolutions when it comes out of storage.

As for the impeller freezing to the housing, its not hard to imagine. Even a fine film of water between the impeller blades and the housing can solidly lock the impeller in place. Doesn't have to be alot of water present.
 

smbrule

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Re: Starting OB below freezing

Fishing the Mississippi below the locks and dams in the winter it was common for anglers (including me) immediately after taking their boat out of the water to tilt the motor down to drain and them to start the motor and let it run for a few seconds--supposedly to get all the water out.

We fished in temperatures as low as 10 degrees F.
 

Frank Acampora

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Re: Starting OB below freezing

Interesting and something I never thought of since I do not boat in freezing weather.

HOWEVER: since ALL rubber impellers that I know of act as positive displacement pumps at low speed, this means that the vanes not directly over the intake hole of the pump WILL trap water-- If frozen, this can lead to broken vanes. Excellent preventive measure that costs nothing!
 

Tacklewasher

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Re: Starting OB below freezing

Fishing the Mississippi below the locks and dams in the winter it was common for anglers (including me) immediately after taking their boat out of the water to tilt the motor down to drain and them to start the motor and let it run for a few seconds--supposedly to get all the water out.

We fished in temperatures as low as 10 degrees F.

My friend does this as well. I'm thinking of adding it to my list when I pack the boat up. I already put both motors all the way down but think a 2-4 second run at home is a good idea.

It doesn't take much water to break things.

On my kicker, I can do a slow pull before starting it but I'm not taking the cowl off the big motor to try to turn it by hand. Probably end up in the drink.
 

ondarvr

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Re: Starting OB below freezing

Seems like sound advice Tacklewasher. On a similar note, someone once told me never to crank a motor over with the starter motor first thing after being stored for a long period. The impeller can stick to the housing and possibly be damaged. I always slowly turn the motor over by hand 1 or 2 revolutions when it comes out of storage.

As for the impeller freezing to the housing, its not hard to imagine. Even a fine film of water between the impeller blades and the housing can solidly lock the impeller in place. Doesn't have to be alot of water present.



The impeller would have no idea whether it was you or the starter turning the motor, so I don't see where it would make a difference.

Starting it out of the water is a bad idea, will 1 or 2 seconds hurt it.....probably not, but this would be where turning it by hand would work...that is if you thought there was going to be an issue with water left in the pump. Old impellers self destruct on occasion all by themselves, this sounds like that may have happened and some thought it was due to water freezing in it. I must say that we fish all winter here and water freezing in the pump has never been an issue.
 

Moody Blue

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Re: Starting OB below freezing

Ondarvar, the reasoning behind pull starting instead of cranking it with the starter is the ability to gently and slowly spin it around as opposed to jerking it to about 300rpm all at once. Does it make a difference, maybe, maybe not :confused:.

In extreme cold conditions, in which I believe you rarely experience, its hard to believe how "stuck" two parts can become when solidly frozen. Just today with temps of only -9C (15F) I had to use a 10Ib sledge hammer to bust a 2x4 piece of lumber free from the frozen ground.
 

ondarvr

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Re: Starting OB below freezing

Cold weather use should be covered in the manual if it needs special procedures, my manuals say nothing about it.

It would be more likely to damage the impellor by starting it out of the water repeatedly than by it freezing. If you feel the need (and it may be real), the correct method would be to turn it by hand right after you take it out of the water, this would let any water that may have not drained from the impellor housing out. This would also allow water to fill the system as soon as it was lowered into the water, this water would instantly thaw it out and release the impellor if it was stuck to the housing.
 
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