Older 25hp Nissan dies

[katlady1313]

Ok so my motor will start and then dies shortly after running in gear only on the water. Did the bucket flushing and it ran fine throtled nicely did not die. First I replaced the fuel tank. Same problem. Cleaned the carb, replaced all fuel lines and gaskets for the fuel system, thinking that was the problem. Noticed that the primer bulb when squeesed will not re-inflate (stays soft) on both the old and new gas tank. So the tank was the first to be fixed, then the fuel system.
I then noticed that that flushing plug/screw was missing will this cause the above problem?

Any info will be great.

My motor looks like this but it's a 25hp 2 stroke

 

[pvanv]

Re: Older 25hp Nissan dies

What is your actual model? When did this problem start? What method did you use to clean the carb? Does the primer bulb get sucked flat? Yes, you need the flushing plug installed.

 

[katlady1313]

Re: Older 25hp Nissan dies

The model is NS25C2. I used a carb cleaner I bought from a marina and air dried all the parts. Yes the primer bulb gets sucked flat and stays flat until the motor dies. (once the motor has died the primer bulb is reinflated). It started doing this after a trip to a very weedy lake last year. It cut out while I was on the lake, but that was the only time during that trip. The following time out is when it happened all the time. There wer no deposits in the carb and the was no dicolouration in or around the carb. I also flushed the motor and it ran fine in the bucket, so I took it to the lake and still had the problem.

 

[pvanv]

Re: Older 25hp Nissan dies

If your primer sucks flat, there is a restriction between it and the fuel in the tank. Possibly a bad fitting or pickup tube, clogged water-separator filter, or a closed valve. The fuel pump is drawing, but the fuel is not flowing. That's what causes the primer bulb to go flat.

 

[katlady1313]

Re: Older 25hp Nissan dies

Ok will check all of that and will let you know how it goes.

 

[TOHATSU GURU]

Re: Older 25hp Nissan dies

Without the water plug bolt in place the engine will run hot and burn up.

 

[katlady1313]

Re: Older 25hp Nissan dies

Ok I fixed the fuel problem. So I put the motor in a bucket of water and it ran, with a few hickup do to playing around with the adjustment screws. while in the bucket I got it running and sounding like it used to. So I but it on the back of my boat to do the real water test I put it in gear and it ran for a few seconds maybe a minute and it died. Could it be do to the thermostat???

 

[Sea Rider]

Re: Older 25hp Nissan dies

Thermo has nothing to do with engine dying unless severely overheated which is not your case, probably air/gas needle out of adjustment or very low rpm's at idle/gear...

Happy Boating

 

[katlady1313]

Re: Older 25hp Nissan dies

The idle is all over the place. it goes up and goes down all by its self. but it stays running until i put it in gear thats when it dies and it won't start for awhile after that. I took the thermostat out to look at it and it is as black as coal. So with that being said could it be the thermostat?

 

[katlady1313]

Re: Older 25hp Nissan dies

What about the stator? Someone told me that the stator could be going or gone! Could that be causing my problem?

 

[Sea Rider]

Re: Older 25hp Nissan dies

You say it's an old engine, how old would that be. Have found that with time all gaskets tends to cede, you'll be surprised on how much you will need to retorque parts to sit same as when engine was new. You seem to have air entering through carb gasket or intake manifold/crankcase. Check carb gasket condiiton, if dried, cracked place a new one and adjust nuts tight.

Torque intake manifold and check if bolts are loose, there are some bolts located at lower portion which are hard to reach, probably will need to take carb off to be within reach, worst case scenario will be to remove head from base to retorque well all bolts sitting radially. Will need a new base gasket as old will probably come out in pieces. Take advantage having head down and retorque head gasket to 30 NM, follow bolt torque sequence.

Happy Boating

 

[katlady1313]

Re: Older 25hp Nissan dies

I checked the thermostat and it's fine.

 

[pvanv]

Re: Older 25hp Nissan dies

What about the stator? Someone told me that the stator could be going or gone! Could that be causing my problem?

That motor does not have a stator.

 

[pvanv]

Re: Older 25hp Nissan dies

The idle is all over the place. it goes up and goes down all by its self. but it stays running until i put it in gear thats when it dies and it won't start for awhile after that. I took the thermostat out to look at it and it is as black as coal. So with that being said could it be the thermostat?

Disassemble the carb. Completely. Clean it. Correctly. Then try again. That motor is old enough to vote, so don't get carried away spending too much on it.

 

[TOHATSU GURU]

Re: Older 25hp Nissan dies

redundant