Valve rotor skirt/web removal?

[bigtubby]

A few years ago I remember a thread here about grinding away the skirt or web between ports on valve rotors but it seems to have disappeared.

Recently I acquired a Yamaha YCB-661 and one of its excellent playing characteristics is a very clean "finger slur". It either was built with this feature or someone has modified it.

Any input/opinions on this mod?

[Dan Schultz]

A few years ago I remember a thread here about grinding away the skirt or web between ports on valve rotors but it seems to have disappeared.

Recently I acquired a Yamaha YCB-661 and one of its excellent playing characteristics is a very clean "finger slur". It either was built with this feature or someone has modified it.

Any input/opinions on this mod?

A few years ago I experimented with removing material from rotor skirts to lessen friction and reduce weight. I thought I put them on my web pages but don't see them there now and cannot locate the images. I still have one of those rotors somewhere. I'll try to dig it out and send you some pics.

[bigtubby]

A few years ago I remember a thread here about grinding away the skirt or web between ports on valve rotors but it seems to have disappeared.

Recently I acquired a Yamaha YCB-661 and one of its excellent playing characteristics is a very clean "finger slur". It either was built with this feature or someone has modified it.

Any input/opinions on this mod?

A few years ago I experimented with removing material from rotor skirts to lessen friction and reduce weight. I thought I put them on my web pages but don't see them there now and cannot locate the images. I still have one of those rotors somewhere. I'll try to dig it out and send you some pics.

Thank you Dan!

What I remember was a thread her on the forum discussing this as an improvement in air flow and cleaner transitions between valve positions. On closer inspection, the Yamaha's ports in the rotors don't go straight through, but are concave. A photo:

[Dan Schultz]

... What I remember was a thread here on the forum discussing this as an improvement in air flow and cleaner transitions between valve positions. On closer inspection, the Yamaha's ports in the rotors don't go straight through, but are concave. A photo:

AHA! This is something quite different from what I was doing. You might try searching for 'scooped' rotors.