Yamaha Piston valve play

[tubaplyer]

How much play is acceptable in a yamaha piston valve? I would like to know when to replace the valve guides (metal old school I am presuming). I can turn them side to side enough to hear a slight clank but it is not ver noticable while playing. Are these valve guides readily available?

Thanks,

A

[Dan Schultz]

How much play is acceptable in a yamaha piston valve? I would like to know when to replace the valve guides (metal old school I am presuming). I can turn them side to side enough to hear a slight clank but it is not ver noticable while playing. Are these valve guides readily available?

Thanks,

A

You said you assumed your guides are metal. You need to look and make sure. What you might have are the new style guides where the plastic is broken and the metal reinforcement tab is exposed. In this case... simply replace the plastic guides.

Yamaha no longer catalogs the metal valve guides. I see them pop up on Ebay once in a while. Someone's new/old stock I guess. It's quite normal for valve guides to have a bit of side to side clearance and they will make a click... click when moved from side to side. Those old metal guides are also somewhat adjustable by virtue of the slot toward the outside.

[SousaSaver]

Is the play from turning the valve? That is what it sounds like. If what you are describing is true, if the valve had what we would think as play and you could hear it clank, it would probably be (in my opinion) unplayable.

Metal valve guides for Yamaha can be purchased through Allied (I think...), but they are very expensive. If you cannot find them, let me know, I might have some in a drawer...