Nissan NS5B Internal Gas Tank Threads Stripped OFF!!?!!

[abp]

I'm on my second internal gas tank (69703162M) for a 5 hp Nissan due to the threads on the neck of the tank being stripped off by the gas cap. I promise I'm not over-tightening the cap . The warranty on the new tank was 90 days and dealer was no help. I hesitate to buy a new one if it will happen again.

Just curious if anyone has had the same problem, if there is a way to repair/replace the treads (doubt it), or if anyone has suggestions as to why it keeps happening - other than cheap plastic. My only thoughts are of the cap being on too tight during the heat, and the internal pressure being too much for the threads to handle.

Thanks for your help!

Adam

1980 O'Day Daysailer II, Nissan NS5B Kicker.

 

[TOHATSU GURU]

Re: Nissan NS5B Internal Gas Tank Threads Stripped OFF!!?!!

Pretty rare...How old is the engine? It has to be at least 11 years old.

 

[abp]

Re: Nissan NS5B Internal Gas Tank Threads Stripped OFF!!?!!

Engine is a 90's model (don't have it in front of me and just bought it last summer). New gas tank is less than one season old.

 

[TOHATSU GURU]

Re: Nissan NS5B Internal Gas Tank Threads Stripped OFF!!?!!

There has not been a problem with the fuel tanks...It's always possible the tank was defective, but it is usually due to someone over tighting the cap and having the vent closed with fuel inside.

 

[trimjb]

Re: Nissan NS5B Internal Gas Tank Threads Stripped OFF!!?!!

I have the same issue. New tank with threads stripped. Past warranty. When I replaced the tank, I did not replace the cap. The threads looked OK. I'm wondering if there could be a difference in the cap/tank threads on the replacement tanks.

TOHATSU GURU -are you saying we should not close the tank cap vent when there is gas in the tank? If so doesn't that mean that the gas should be drained after every use? I leave mine at my boat and close the vent to keep moisture our.
Could this be another Ethanol issue?
I'm looking for parts to convert to a external only fuel tank. I will remove the broken internal tank and blank off the filler hole. Looks link a good place for a stern light.

 

[abp]

Re: Nissan NS5B Internal Gas Tank Threads Stripped OFF!!?!!

I did purchase a new cap to go with the new tank, so a mix match wasn't the issue in my case. I'm about to order another for $70, I'll give it one last try.

 

[TOHATSU GURU]

Re: Nissan NS5B Internal Gas Tank Threads Stripped OFF!!?!!

I have the same issue. New tank with threads stripped. Past warranty. When I replaced the tank, I did not replace the cap. The threads looked OK. I'm wondering if there could be a difference in the cap/tank threads on the replacement tanks.

TOHATSU GURU -are you saying we should not close the tank cap vent when there is gas in the tank? If so doesn't that mean that the gas should be drained after every use? I leave mine at my boat and close the vent to keep moisture our.
Could this be another Ethanol issue?
I'm looking for parts to convert to a external only fuel tank. I will remove the broken internal tank and blank off the filler hole. Looks link a good place for a stern light.

Not exactly. It shouldn't make a difference on a tank with healthy threads. But, all it takes is one cross thread to damage the threads on the tank. With weakened threads it would be possible that a build up of pressure in the tank could force the cap and fuel tank threads into a fight that the tank will loose. Basically what I'm trying to get across here is that it is not a defective tank issue, its an op malfunction.

 

[Sailorboy58]

Re: Nissan NS5B Internal Gas Tank Threads Stripped OFF!!?!!

I have the same engine and have had to replace the internal fuel tank 5 times (Approx. $70 each time!!!) due to the threads on the tank portion of the cap stripping off. I'm very careful with not tightening the cap too tightly and believe the plastic used in the tank cap fitting is too weak for the application, definately a design flaw or defective plastic. Nissan and dealers have not been willing to acknowledge something is defective with the tank cap. Very Frustrating!

 

[TOHATSU GURU]

Re: Nissan NS5B Internal Gas Tank Threads Stripped OFF!!?!!

There is not anything wrong with the tanks...It's just you. What's the serial number of your engine? I'll be happy to pull up the service history of it and see if there was a unique problem with your engine.

 

[Sailorboy58]

Re: Nissan NS5B Internal Gas Tank Threads Stripped OFF!!?!!

No, it's definately a defect in either the cap design or the quality of the plastic. As I said, after it happened the first time I've been VERY careful to not over tighten the tank cap and the threads still stripped of the fourth tank. I've now replaced the tank three times and the previous owner replaced it once for the same problem. Nissan should admit to the defect, and provide a new tank. Better yet, improve the durability of the tank cap component. The serial No. is 369-197858

 

[pvanv]

Re: Nissan NS5B Internal Gas Tank Threads Stripped OFF!!?!!

Of hundreds of these motors we have seen, all tank/cap issues have been due to the technique of the user. Yes, anyone could get a bad tank, but based on your particular track record, I doubt that to be the case here. The same plastic is used on all the internal tanks of all sizes, so the material is not the issue, or every motor from 2 hp through 6 hp would have the problem. I recommend that you review your technique.

 

[gil marlin]

Adam is right, I am having the same issue. The tank seeps when in the tilted position, hand tightened the cap and it still leaked. I bought a new cap and it leaked as well. I never felt the cap "pop" while tightening, yet it leaks. The threads appear to be all there on the tank, but they must be the problem. I use a remote tank so I just gave up on the cap issue. If you can't tighten hand tighten the cap so it doesn't leak, there is a problem with threads on the tank or the overall design, not the user...

 

[GA_Boater]

Old inactive thread. Closed