Does anyone have a clearer image of the news letter number 315 than the one in the tech library? I want a clearer picture of the piston modification for the SC500 to stop it seizing. Thanks 

Does your piston have slots by the wrist pin like this one?, the bulletin came out before the new piston came out. My recent SC500 had the new style, didn’t have any problem seizing. When I bought one of those bikes new I added slides, shortly after the new piston came out. You can add crosshatching on the corners with some sandpaper and that will help.

Yamaha made changes to the replacement pistons. You wouldn't want/need to do any mods unless you were sure you had an early piston still. 

Does your piston have slots on each side of the wrist pin?

New style pistons 





  

It does have the slots both sides of the pin so I will leave it alone. Thanks for the replies.

You can tell by the surface finish and color that it is made from the rare earth element know as Unobtainium!