Troubleshooting response issues!

[Tbarh]

I have a 1960 Holton 168 (early version tr150) with a beautiful dense , complex sound.. However , the response are very tight in a strange way.. It is like the bell section ( tried different slides/same results) either have a misalignment or are to heavily braced or have misaligned valve ports or something.. The horn are pretty worn in places and could of course be over its prime, but i would like to know what options i have Before moving it.. Horns with this kind of sound are rare. So; what are my options, and what are the usual suspects with issues like this?

Thanks!

[BGuttman]

First thing to look for: misaligned ports. Best done with a borescope,but you may see the problem looking into the slide receiver.

Look for leaks.

Make sure all tuning slides are lubed.

Try squirting some oil into the valve from the slide receiver -- could be a worn rotor.

[GabrielRice]

Second - have the instrument given a good once-over and the valve checked out by a professional.

[bigbandbone]

Also, make sure the water key cork is sealing, and no obstructions in the bore. I've pulled a lot of foreign objects out of bell sections that the player had no idea how they got in there!!!