Why does a Nissan 15 hp outboard keep dying in (it seems) cold weather?

bluwtr

Cadet
Joined
Jun 3, 2007
Messages
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I've had problems with clogged Venturi tubes due to bad gas. I've solved that problem. Last year it got very cold where I live (18 in south MS). I went duck hunting and the motor ran fine on the way in. After a few hours of hunting it died on the way out. It was relatively cold this morning when I went out and it acted the same. I haven't checked the fuel filter again, but if that's not the problem, then what is?
When I discoverd the bad gas, I emptied the tank. It had gunk in the bottom so I washed the tank with soapy water, rinsed it several times, dried it with acetone and let it sit outside for a day to further dry. Then I added tank water remover and carb cleaner. Would a frozen thermostat cause problems like this? I've made several runs around the river on the new gas and have had no problems until this moring.

Thanks to any and all suggestions.

W
 

Sea Rider

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Sep 20, 2008
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Re: Why does a Nissan 15 hp outboard keep dying in (it seems) cold weather?

Are you using ethanol mixed fuel ?
 

TOHATSU GURU

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Jul 22, 2004
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Re: Why does a Nissan 15 hp outboard keep dying in (it seems) cold weather?

The problem could be anything. However, start with the fuel system first. Chances are you have contaminated fuel again or you may have trash in the carburetor. Are you running the engine dry after ever use?

"Then I added tank water remover and carb cleaner"

I'm not sure what you meant by this. Additives to the fuel? If so, products like these do not cure a problem. At best they may act as a preventative when the engine is running correctly. In general, once you have an actual problem, canned products are useless to solve the problem as the are so mild that the cannot dissolve varnish and/or absorb water. Pre-ethanol laced fuel was a little more tolerant of alcohol absorption products, but today's fuel really does not do well with them.
 

bluwtr

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Re: Why does a Nissan 15 hp outboard keep dying in (it seems) cold weather?

Yes I am using ethanol blended fuels. There are no other options around here where I live.

Sorry about not being clear. The first thing I did when I cleaned out my fuel tank (6 gal plastic btw) was to use a high pressure water spray and soap. Because I put water into the tank I wanted to make sure I removed all of it. I first washed the tank with acetone. I poured that out and let the tank sit outside for a day--at the time it was still warm down here. I added the "gas tank water remover" when I filled the tank as a precaution to remove any small amount of water left in the tank.

I do not run the tank dry after every use because I try and hunt as often as possible. Also that would get expensive fast plus this motor doesn't burn much fuel. Would take a while to use it all.

I have taken the carb apart several times now and it did have varnish and such in it but I cleaned it out.

Like I said, is it possible that the thermostat is sticking when it gets cold or some other cold related issue. I wouldn't think a 15 would be that complex. What about deteration of the fuel line?

Thanks
 

TOHATSU GURU

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Re: Why does a Nissan 15 hp outboard keep dying in (it seems) cold weather?

The thermostat regulates water flow and cannot affect the running of the motor...Unless the engine was overheating due to the thermostat being stuck and that isn't the problem here. You have a dirty carburetor. You have to soak the carburetor, for three hours, in a can of carburetor dip. No spray will do it....And you have to run the engine dry with each use. That's four tablespoons of fuel you are going to use up at the end of each and every trip. If you don't run it dry you are going to be cleaning your carburetor every other month. It is possible that your fuel line could be suffering from the effects of too much alcohol. The line is fine up to 10%, but at anything above that it will start to come apart. Unfortunately a lot of the gas is creeping up above 10% depending on the honesty of the refinery/distributor/dealer. I have heard of some stations that have been caught with over 20%. If your fuel in your line is dark brown or black after a month of sitting your line is coming apart. Just keep an eye on it.
 

bluwtr

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Re: Why does a Nissan 15 hp outboard keep dying in (it seems) cold weather?

:mad::mad: My reply was just erased!

Anyway, thanks Capt. for the reply. I misunderstood your meaning of running it dry--I thought you meant the entire tank--not just the motor.

The reason I asked about the thermostat was if it had frozen shut if the motor had an overheat sensor that would kill the motor. I imagine not on a small motor like this.

I've broken down the carb a couple of times and cleaned it really well, but I know I couldn't get into all of the ports and such. Where can I get the carb soak?

My father-in-law told me tonight about a station locally that doesn't have blended fuel, so I will be buying from them from now on.

One other question--can I add an inline fuel filter for this motor as well? The only "filter" it has is a little bowl before the reed/ check valves. It doesn't even have a screen.

Thanks again.

W
 

TOHATSU GURU

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Re: Why does a Nissan 15 hp outboard keep dying in (it seems) cold weather?

Carb dip can be purchased at any auto parts store in a one gallon can. Any filter will do on it, but there is a white plastic filter in line on the fuel line either right before or right after the fuel pump.
 

bluwtr

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Re: Why does a Nissan 15 hp outboard keep dying in (it seems) cold weather?

I will pick some up. Thanks.

There is a "filter" before the fuel pump. That is the bowl filter without a screen I mentioned. I was asking if I could put an inline filter between the bulb and the fuel hose inlet. I wouldn't imagine it would cause any pressure problems since it is a vacuum system would it?

Thanks again.
 

TOHATSU GURU

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Re: Why does a Nissan 15 hp outboard keep dying in (it seems) cold weather?

No problem at all. In fact, it's always a great idea to add on an additional filter. I would place the filter just before the fuel pump. That way it has a better chance of catching trash.
 

bluwtr

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Re: Why does a Nissan 15 hp outboard keep dying in (it seems) cold weather?

Will do Capt.

Again, thanks for all of the help. I really appreciate it.

W
 

bluwtr

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Jun 3, 2007
Messages
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Re: Why does a Nissan 15 hp outboard keep dying in (it seems) cold weather?

This is what the gas from my tank looked like. I think this was the major problem. I bought this gas in November. I soaked the carb and have reassembled and reinstalled. Obviously I emptied the tank and got new gas and oil. Havn't run the motor yet (ran out of daylight), but will report back once I do.

W

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Re: Why does a Nissan 15 hp outboard keep dying in (it seems) cold weather?

I have found that my two stroke Evinrude will ice up in the carburetor when it is cold and damp. The vacuum in the carburetor will cause a layer of ice to form around the air intake throat.

An iced carb will cause the engine to choke out and die.

Icing usually occurs at temperatures slightly above freezing when the dampness in the cold air freezes to the inside of the carburetor.

Allowing the engine to sit after being run will allow the engine heat to melt the ice but the ice will reform when you run again.

I have used a propane torch to melt the ice on those occasions when the icing was really bad. A quick blast with the flame of a propane torch will melt the ice (provided you have a clear shot at the carb throat.
 

bluwtr

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Re: Why does a Nissan 15 hp outboard keep dying in (it seems) cold weather?

I will keep the icing problem in mind.

Thanks,

W
 
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