Oil cap gasket

[Ash]

Does the xs2 need an oil tank cap gasket?

 

[cra-z1]

I assume you are talking about the dip stick. Well you may not need one but there is a groove under the cap for one. I think mine is a cork or some sort of plastic. If yours is missing I would go to the hardware store and chose an o-ring that sits in the groove and will sit slightly above the face. The seal will prevent the cap from unscrewing during running

 

[5twins]

Yes, it is cork, and Yamaha still sells it. Stop by one of your local Yamaha dealers and spend 3 bucks.