XS1/2 Gas Cap Bracket Mystery Solved

[Jim]

I've seen multiple discussions here in the forums about how the gas cap flange is installed on the XS1 and XS2 tanks. The confusion stems from the tank being steel and the flange being aluminum....
It pretty obvious once all the paint's stripped away. The tank has a steel "tube" or flange about 3/4" tall welded to the tank. The cast aluminum flange is then pressed down over the outside of the tube. Then the steel tube is flared (crimped) to fold over a lip cast into the flange, locking it in place. It's pretty obvious and simple once you see it. Although... damned if I know why Yamaha chose aluminum to cast the flange. Things that make you go hmmm.

 

[Mailman]

Well that’s interesting! I knew the inner part of the neck was steel and the outer aluminum. I always thought that somehow it was soldered on because I could see what appears to be hardened drips at the bottom edges.

 

[Jim]

Well that’s interesting! I knew the inner part of the neck was steel and the outer aluminum. I always thought that somehow it was soldered on because I could see what appears to be hardened drips at the bottom edges.
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Yeah, always thought it was odd because steel and aluminum are incompatible as far as welding, brazing or soldering. With it all cleaned up you can clearly see the steel from the aluminum. It's obvious once you know.