2 stroke Nissan 8 hp motor problems.

Ariye14

Recruit
Joined
Aug 27, 2009
Messages
1
I'm in dire need of help.

I possess a 8 hp nissan outboard motor, from around the 1990-1992 years.
The problem is that the motor starts very well, when keeping on single turns it works fine, when changing gear to front it works fine and when I get to the max or close to it, after 2-3 minutes it just stops and overheats. Lately we have changed the impeller in the water pomp, the water goes out fine from the side of the motor. from the backside, water comes out with steam.
What should I do to resolve the problem?

Thank you,
 

pvanv

Admiral
Joined
Apr 20, 2008
Messages
6,509
Re: 2 stroke Nissan 8 hp motor problems.

Sounds like the cooling system is clogged with salt and corrosion, OR the thermostat may be stuck shut.

Easiest thing to do is pull the stat and test it, or just replace it. If that fixes everything, you're home free. If not, a thorough de-scaling of the cooling system is in order, and that may involve pulling the powerhead off.

If you don't have one, a Factory service manual is available at any Tohatsu/Nissan dealer, and is a good investment.
 

mmccoy555

Petty Officer 2nd Class
Joined
Jun 3, 2009
Messages
131
Re: 2 stroke Nissan 8 hp motor problems.

Try sprayin some Merc Power Tune(or equivelant) through the **** tube. Then blow out with compressed air. This fixes the clog more than not. If not there are only six bolts to remove the powerhead and clean the water jackets. Make sure the tube coming from the water pump to the powerhead is clear as well.
 

Sea Rider

Supreme Mariner
Joined
Sep 20, 2008
Messages
12,345
Re: 2 stroke Nissan 8 hp motor problems.

17 years of use is a lot of time, if engine has not received a previous water passages maintenence, it's time for it, it's probably full of incrusted salt formations bloking water through, take cylinder head off, clean all water passages including crankcase passages, change gasket & thermostat, torque to specs, take advantage of stripped engine, decarbonize cylinder head, pistons, change plugs, if all of the previous recommneded issues doesn't work to solve overheating problems.

Will have a new like engine working perfect as in the good old days.

Happy Boating
 

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