GTR 350 fuel tank leaks

[ridered]

This post is for a heads up. Both the tanks I have leak where the petcock stub comes out of the tank. This is probally a common problem or I just got Lucky to have the problem with both my tanks. Before spending the big bucks to restore your tank I would recommend running a bead around the stub before sending to the chromer for extra insurance, as it may save allot of heartache in the future.
Mike

[Toystoretom]

I don't know for sure, but that may be the lowest point in the tank and that would be where water would sit and cause rust. I have one tank that is unbelievably rusty on the inside, so much so that the gas cap even came apart due to rusting. I have to admit, the metal that Bridgestone used in the tanks is pretty substantial and those are some heavy duty tanks. I'll bet even my rusty tank could be saved. You can't say that about the other Jap manufacturers back then, I have a nice Suzuki tank that the sheet metal is so thin you can push it in with your thumb. If that had rusted it would be scrap.

[ridered]

Don't think it had to do with rust as both tanks were clean inside. I believe the process that was used to install the threaded fitting for the petcock was not a good one. What happens is if there is a leak in that area and someone grabs a big wrench to try and tighten the petcock nut their is a good chance that the fitting will break loose.
Mike

[rocketman]

Mike,I think a lot of folks just don't like to see tanks lined,even though theres nothing wrong with it even on a good tank. I believe some manufacturers may have even lined their tanks from new. I have a Yamaha AT1 that had an extremely thin bottom on one side. After cleaning it,a bunch of pinholes came thru. I ground clean the remainder of the outside surface of the bottom making sure not to extend up onto the side. I then "glued" a flat sheet metal patch,cut to fit the exact shape of the bottom of the tank with 2 part SEM epoxy. Then lined the inside of the tank. I painted the bottom only,up to the edge with black paint,tank is yellow. When you look at the bike it still has all the factory color on the tank and you can't tell there were any repairs till you bend down and look up from the bottom. Since I didn't weld anything,the factory paint is not burned or bubbled. Repair is 2-3 years old now and still holding strong. As long as the fitting is secure,this epoxy could easily be used on the outside around the fuel outlet if properly prepped,and would be virtually invisible once painted. If your still nervous about it,you can always line the tank.  Mark.

[ridered]

Hi Rocketman
I solved the problem on my tanks. I took them to a radiator shop and they put a nice weld around where the fitting comes thru the tank. My main reason for the post was to let members know of the potential weak spot so they can repair it before sending their tanks to chrome.
Hope I was able to save someone some grief down the road.
Mike

[rocketman]

Yes Mike,good information for sure.    Thanks,Mark.

[Toystoretom]

That is a good tip.

Did the radiator shop weld it (that metal is thick!) or did they braze it?

[ridered]

The tank that I'm chroming was brazed by the plater, he wanted to do the repair himself. The tank repaired by the radiator shop appears to be silver soldered the same process they use to repair radiator leaks he also took care of a pinhole that came up during blasting. The idea is basically to put a seal weld at that joint and add a little extra strength. If I ever run across a trashed tank my curiosity will cut it open to see how they installed that fitting as I couldn't see any welding from the outside.
Mike

[Jeff Bar]

Mike

I think the tank fitting was pressed in and sliver soldered, I have one on a Hodaka leak, it was assembled that way,

Jeff Bar

[ridered]

Hi Jeff
I Think your right it does appear it was pressed in and probally soldered from the inside. I have had every piece apart on my GTR and That is the only design flaw I have come across. The way these bikes were built really amazes me. Every part on the GTR is of the highest quality I've seen from any manufacturer.

[reed]

Mike
I with you on the quality on the Bridgestone GTR!
Thanks.
Steve.