Can an older Yamaha 321 be fitted with newer valve guides?

[drewfus]

Looking at an early edition of a YBB321 later today, which I am guessing has the guides on the piston. Can these be updated for the plastic guides. Would I want to? Dude wants 850 for the horn.

[Dan Schultz]

I think the old-style brass guides that are mounted IN the top of the piston are far better for classrooms where kids are constantly 'fiddling' with the stems and fingerbuttons. The new-style plastic guides might be a bit quieter but I don't see any real reason to change to them.

I suppose a good machinist could put the small hole in the top of the piston for the plastic guides. Then all you would need (besides the guides) is the washer and new-style stem.

[ppalan]

I'm also interested in answers to this question although for a slightly different reason. (My apologies if this isn't exactly on point ) I also have an older Yamaha, a YEB-321 with metal guides. They are noisy (annoying to me not necessarily to anyone else) and no matter how often I oil they don't seem to get any quieter. I've been thinking of getting them replaced. Is there anything else that could be done short of the "surgery" mentioned by Mr. Schultz that seems to be required. I'm assuming nothing of a grease-like nature would be an appropriate solution.

Pete

[Dan Schultz]

I'm also interested in answers to this question although for a slightly different reason. (My apologies if this isn't exactly on point ) I also have an older Yamaha, a YEB-321 with metal guides. They are noisy (annoying to me not necessarily to anyone else) and no matter how often I oil they don't seem to get any quieter. I've been thinking of getting them replaced. Is there anything else that could be done short of the "surgery" mentioned by Mr. Schultz that seems to be required. I'm assuming nothing of a grease-like nature would be an appropriate solution.

Pete

The tighter the old-style guides are... the less noisy they will be. If they are worn... simply replace them. Also... notice that there is a small slit where the brass guide fits into the slot. That can be spread a bit to tighten them up.

I've not seen any aftermarket plastic guides to replace those brass ones. But... I suppose a person could 'whittle' some of those out of Nylon without too much trouble.

[drewfus]

Well, I bought the horn, the guy took $500 for it. Thanks for the advice here and on the phone Dan. Great to be back playing.

[Lee Stofer]

There are several options for re-fitting an older Yamaha 321 tuba or euphonium. One consideration is that I believe the older pistons are longer, so putting a plastic valve guide on top would not leave enough room for the felt without putting the valve out of alignment. In that case, Yamaha makes a re-fit piston assembly, a new valve that is shorter that uses the newest valve guide system and will properly align the piston with the ports.

Otherwise, it would be possible to fabricate a nylon valve guide set-up for the side of the existing piston, or fit it with a new Yamaha metal guide, which should be readily available. I keep them in stock, "just in case".

[Dan Schultz]

There are several options for re-fitting an older Yamaha 321 tuba or euphonium. One consideration is that I believe the older pistons are longer, so putting a plastic valve guide on top would not leave enough room for the felt without putting the valve out of alignment. .....

This is true. But... while one is busy putting the extra hole in the top of the piston to align the guide.... about 3mm can also be turned off the top of the piston. There's plenty of 'meat' there to do it.

[daytontuba]

If you decide to put in a new set of guides (which I have done on my 70's vintage 321), it takes about two minutes a valve (assuming you have really cleaned the valve casings) - just be careful to not lose those tiny screws that hold them in!