Gas Tank

[Patrizio]

Hello again, (this is getting pretty annoying ). So came to the conclusion I bought a dud of a bike. It has given me nothing but headaches. Anyways, my gas tank is leaking from the top left bolt hole area. It is a fairly serious leak. I’m assuming a bolt got jammed in too far? It seems pretty impossible to find a new gas tank online so am wondering if anyone had any ideas to seal the tank? I’m assuming I’ll have to rip off the threaded spot to find the hole. Thanks

[DannoXYZ]

yeah, two different size bolts to hold fairing onto tank. Longer one goes on bottom where there's nothing behind. But shorter one is required for upper hole as there's only about 5mm of thread. Put longer bolt in there....

I've found with age of these bikes and numbers of previous owners, half of whom are below average, that most tanks have been punctured. Out of previous 8 pre-gens I've restored and sold off, about 3/4th had punctured tanks.

Don't even think about JB-Weld! That stuff has caused more crappy repairs on cars & motos than anything else. IT WILL NOT WORK BECAUSE THAT CRAP IS NOT PETROL PROOF!!!

I've found it's easiest to drain tank, let sit outside for a day, then rinse with soapy water gets it ready for welding. Then I braze some brass into puncture hole (positioned flat so hole is up & down). I give it a little extra heat and brass slides to bottom of hole. Let cool and hole is plugged with metal!!! Actual time spent is about 15-min. Most of that is sanding and cleaning to prep that hole!

[CZroe]

Originally Posted by DannoXYZ

yeah, two different size bolts to hold fairing onto tank. Longer one goes on bottom where there's nothing behind. But shorter one is required for upper home as there's only about 5mm of thread. Put longer bolt in there....

I've found with age of these bikes and numbers of previous owners, half of whom are below average, that most tanks have been punctured. Out of previous 8 pre-gens I've restored and sold off, about 3/4th had punctured tanks.

Don't even think about JB-Weld! That stuff has caused more crappy repairs on cars & motos than anything else. IT WILL NOT WORK BECAUSE THAT CRAP IS NOT PETROL PROOF!!!

I've found it's easiest to drain tank, let sit outside for a day, then rinse with soapy water gets it ready for welding. Then I braze some brass into puncture hole (positioned flat so hole is up & down). I give it a little extra heat and brass slides to bottom of hole. Let cool and hole is plugged with metal!!! Actual time spent is about 15-min. Most of that is sanding and cleaning to prep that hole!

Yeah. In my experience its seems more than half EX250F tanks will leak from there when you fill up because a previous owner mixed up the bolts and punctured the tank. Perhaps Kawasaki should've only supplied the shorter ones for all fairing bolts. It seems some people just avoid filling the tank up that high.

What about JB TankWeld? It's gotta tolerate petrol since it's supposedly made for fuel tanks and such. I found some at the salvage store and bought it because I have a punctured EX250F tank in storage somewhere. Sure enough, I searched and this dude was using it to fix the exact same issue (language):
https://www.youtube.com/watch?v=QfpTUxLGCjM

I always intended to restore mine by inserting a headless set screw with a shorter bolt in the same hole, maybe with something like JB TankWeld smooshed between them. Unless there is a gap between the threaded hole and the tank rupture, I expect it to work.

Does the brazing method leave you with no hole for mounting the fairing?

[DannoXYZ]

Sure let's try the TankWeld! Can't hurt.

Brazing puts the brass at bottom of threads. Leaving you with top 5mm threads to use. Have to add a little extra heat so it flows downwards. Just matter of technique.

[eltel]

Originally Posted by DannoXYZ

Don't even think about JB-Weld! That stuff has caused more crappy repairs on cars & motos than anything else. IT WILL NOT WORK BECAUSE THAT CRAP IS NOT PETROL PROOF!!!

You need the "Marine Weld" product from JB, it is fuel resistant and will do a perfect job on the tank.

Get a cheap syringe and try any layer some inside the thread hole 6-8mm deep, let it dry hard. Then syringe some more in to a depth of around 5mm. Before it drys make sure you have depth for the screw and run it in to its normal depth to push the Marine Weld back. Then run marine weld around all four sides of the raised bracket sealing it completely. Run a wet finger around to make it neat and smooth.

Job done - I did the very same thing and punctured my tank a few days ago. JB Weld Marine Weld does a brilliant job.

[DB7562]

I had the same issue, but the previous owner had used something to block the leak. I didn't see it until I removed the fairing. Ended up paying $570 for the repair...but no more fuel leak.