Posted by Ed Heckman on December 23, 2000 at 19:49:07:
In Reply to: Problems with rotary valves posted by Tracy Bedgood on December 23, 2000 at 19:16:32:
I also have a Miraphone 186. I've found that whenever the valves are noisy, it's because something is loose.
First, check the slotted screw at the top of the valve assembly. It should be tight enough that it doesn't independently of the valve. Just be sure not to make it too tight!
Next, make sure the valve caps on the back are snug, i.e. just a tiny bit beyond where they move freely.
Finally, you can try adjust the set screw in the back valve caps. Turn it in a little bit at a time. (About 1/16th of a turn.) Then check the action. BE VERY CAREFUL WITH THIS! If you tighten it too much, it will slow down your valves. There's very little tolerance between slowed and stopped completely. When you're done with this your valves should still move freely, only with less noise than before.
All this assumes that your valves are properly lubricated. I've become a fan of BiNaK 495, but you probable have something else. Before I switched to BiNak, I was using three different lubricants on my horn: a relatively heavy slide lube, a medium weight lube on the valve spindles and connecting rod ball joints, and a light rotary oil put down the tubes for the valve face.
Ed "What the" Heckman