Posted by Yamaha uses Monel on April 03, 2003 at 15:26:44:
In Reply to: Re: Yamaha valves posted by js on April 03, 2003 at 00:14:41:
Yamaha uses Monel on all their valves.
I personally call them dirtel. They have very close tolerance and can just be a PITA.
Most trumpet players I know wipe them down after every time they play to help keep it to a minimum.
Pro oil worked very good for a friend of mine w a YEP 642 that had same problems.
Good Luck