Problem with 2002 Nissan 6hp 4 stroke.

[Tronald]

I just bought this thing and took it out and it was really hard starting, but when I did manage to get it started, it seemed to run fine except for when I opened it up. It started doing this weird thing where it would act as if the prop were slipping and then it acted like it was out of gas and quit on me. I pulled the line off of the output side of the fuel pump and it seems to be pumping fuel fine. Hmmm....not sure here.

I had to row it home. Any thoughts??

Tronald

 

[pvanv]

Re: Problem with 2002 Nissan 6hp 4 stroke.

Assuming the mechanical systems are good (check compression), you need to verify whether you have an issue with the ignition (not common) or carburetion (likely). Spark plug condition (and checking for spark) will tell you a lot. If the motor has an unknown service history, or if you know that it was laid up for a while with old fuel in the carb, odds are that the carb needs a proper and thorough cleaning and adjustment. Fuel delivery to the carb inlet is not enough -- the carb itself also has to be in proper working order. Full info is in the Factory service manual, available from any dealer (including me), and is a worthwhile investment.

 

[Tronald]

Re: Problem with 2002 Nissan 6hp 4 stroke.

Thanks much pvanv!

OK, I disassembled and soaked the carb in a quality carb cleaner and it runs a whole lot better EXCEPT at wide open throttle, there is an annoying mis. I'm suspecting that it's running too lean. There is only one mixture screw, located at the rear of the carb (manifold side) and that seems to do little.

Any advise?

Tronald

 

[TOHATSU GURU]

Re: Problem with 2002 Nissan 6hp 4 stroke.

Clean it again...Sometimes you have to do it two or three times.

 

[WN2712NJ]

Re: Problem with 2002 Nissan 6hp 4 stroke.

On the miss at full throttle - T'Guru will know for sure, but is it possible that this motor has a rev limiter, and you are hitting max RPMs? My 9.9 Bigfoot definitely had that issue pushing a small skiff around until I changed out the factory 4 blade "thrust" prop for a 3 blade "speed" prop. There is definitely a pronounced miss when the rev limiter kicks in.

-dm

 

[pvanv]

Re: Problem with 2002 Nissan 6hp 4 stroke.

On the miss at full throttle - T'Guru will know for sure, but is it possible that this motor has a rev limiter, and you are hitting max RPMs? My 9.9 Bigfoot definitely had that issue pushing a small skiff around until I changed out the factory 4 blade "thrust" prop for a 3 blade "speed" prop. There is definitely a pronounced miss when the rev limiter kicks in.

-dm

Yes, these motors do indeed have a rev limiter. So if testing in a tank that's a bit too small, with a lot of ventilation, it would be possible to over-rev. A good shop tach would reveal that.