Nissan NS5B 5hp Outboard water pump, lower end repair

[NavySailor]

Hey guys - happy 4th to everyone. I've got a question. My little Nissan that came with my boat that I just got back in May is giving me some problems.

I successfully completed an engine run back on May 21st. Didn't try to use it again until last Sat. Took the boat to the dock, launched her, fired up the motor which ran for about 20 seconds and kaput - engine no workie. It died when I tried to throttle it down a bit. I tried everything to get her to come back on and nothing.

I just tried firing it up again after letting it hang on the engine mount on the boat for a week and zippy. Just won't fire off. I'm going to go buy a new spark plug and see if that's the problem.

Any other ideas? I really want to take the boat out tomorrow but I don't want to get out into the Potomac without any motor back up. (I don't have enough experience to just use the sails).

This is the manual for the NS5B - http://www.nissanmarine.com/tech_talk/p ... 5B_5BS.pdf

Here's the motor when it last worked - and yes, it's got cooling water coming out. Fuel vent is open, etc...

[NavySailor]

Got a new spark plug and installed it. That was not the problem.

[Gypsea Wind]

Sounds like the same symptoms with a 9.9 evenrude that I had. Ended up being the magneto.

[yukonbob]

Try pulling the float bowl and carb and giving them a clean. Old gas with ethanol will leave varnish overtime that clogs fuel lines carb ect. Probably want to empty the gas tank as well and put fresh premium gas in it, especially if you're not running it all the time.

[seahouse]

Does the gas smell bad? Unless you know for certain that the gas is fresh, or that a stabilizer was added to it, assume it's not. Drain the old gas from the carb, add new fresh gas (as Bob says, high octane will improve your chances, and for several reasons) and try again. It's the next easiest thing to try. In fact, if the gas is not fresh, don 't try anything else without changing the gas first.

-B.

[133bhp]

likely the idle jet is clogged. having to use choke to keep running etc. I have to run till dry AND drain the float bowl, else will gum up.

[NavySailor]

Thanks guys - it had about 1/4 of a tank of old gas. I just added new gas/oil to it.

I was messing with it yesterday and the stupid gear lever broke! ARGH

I read online last night that some people got away with just removing the drain screw and letting the fuel out. I've done some work on my 1300cc motorcycle but never a little engine like this.
http://www.boats.net/parts/search/Nissa ... parts.html

Anyway, I'm finishing (I hope) my deck project today. I'll tear into the engine if I am done early enough. If not, there's always tomorrow.

[NavySailor]

I got the motor running again yesterday. I drained all the fuel, removed the fuel line and then pulled the carb.

First off, I removed the drain screw expecting fuel to come out and I got nothing. I thought that was weird. So I took the float chamber off next. It was completely dry and empty. Just a little sludge had solidified to the bottom of the chamber. (In the photo I had just sprayed some WD40 on it prior to reassembly.



I checked the float and it looked good as well. At this point I began thinking it was a fuel flow problem so I removed the fuel supply hose and it was all good. I got a tiny LED flashlight and looked inside of the tank and found tiny slivers/shards whatever laying around the supply valve. No idea where they came from. I filled up the empty tank a few times with water and dumped it out. Dried it all out with a rag.

I reassembled everything, put in new gas with oil and after a few pulls - success! Turned her on and off a few times yesterday afternoon and she kept on working

[NavySailor]

So I was talking to some guys at work (bunch of fighter engine engineers) and the consensus is that the carb bowl lost fuel when I laid the motor down in the back of the jeep and the bowl just never filled back up right.

I was uncomfortable towing the boat (max speed about 50) the 10 miles to the boat ramp with the motor hanging off the back end. Do you guys tow with the motor mounted?

[Catigale]

You can. Lash it up tight so it can't flail around.

[NavySailor]

Hey guys - I could really use your help with this one. I'm still having engine problems.

So, I took the boat out again, and the motor didn't work at first. (Complete story here-http://www.macgregorsailors.com/forum/v ... 10&t=23461)

One of my kids got it fired up finally once we were out and I'm at a loss for what's going on with this thing. The engine started, we let it idle for a couple of minutes and then gave it some forward throttle. The engine rev's up, cooling water is coming out in a constant stream, the water appears to be churning from the rotation of the propeller but we have ZERO momentum. The prop appears to be turning but the motor isn't providing any thrust whatsoever. Tried reverse, no joy there either.

I dropped it off at a local marina-engine repair place last week. They told me they'd have an answer for me in a couple of days. 5 days later I contacted them and they still hadn't gotten to my job. The owner thinks I need a complete carb cleaning and a new water pump. (Of course he never tore anything apart while the motor was there. That was just his guess.) Well, the motor is back in my garage today and I'm going to try and crack this nut myself (with the help of this forum and the wonderful internet!)

So - you guys have any ideas of what I should be looking at? Magneto? Driveshaft?

thanks!

[seahouse]

Check to make sure that the prop is not slipping on the shock-absorbing rubber ring around its hub, or other provision for this that a small motor might have, that might allow the prop drive to slip.
-B.

[NavySailor]

I'll check that out. Going to try and take apart some of it later today.

[Catigale]

It probably just has a shear pin. The prop will turn if the pin is broken, but with no thrust.

[NavySailor]

It probably just has a shear pin. The prop will turn if the pin is broken, but with no thrust.

Thanks & I hope you get that trailer issue resolved without too much of a headache!