Yamaha 621 valve guide problems

[tbn.al]

I sold a 621 to a nice tubenetter in LA a couple of months ago and he reports a chronic sticking 1st valve. I PM'd Matt Walters and he thinks it's probably a valve guide. I have seen many posts concerning the plastic valve guide problems but can't remember if it pertains to this model. Can they just mess up all at once? The valves were the best part of the horn when I had it. Sorry for the ignorance but I'm a rotor kind of guy. I also would like a recomendation for a competent tech in LA for the buyer.

[Rick Denney]

I have seen many posts concerning the plastic valve guide problems but can't remember if it pertains to this model.

Yes, the 621 uses flat plastic tackets clamped between the stem and the top of the piston.

My 621 came originally with hard plastic tackets that looked like Delrin or something similar. They wore quickly, but never caused sticking. I talked to the Yamaha folks and they sent me two sets of tackets made of a new material. These looked more like polyethylene. They lasted a dozen years and I replaced on when Matt cleaned it a few years ago.

Perhaps the new owner is applying a little sideways force on the valve in a way you never did. This might cause the tackets to wear quickly.

I would have him or his repairman talk to the Yamaha folks about improved replacements, and then keep an extra set in your case. The advantage to this design is that the tackets are easy to replace in the field.

Rick "been there, done that" Denney

[Dr. Dave]

Great master technician in LA is Robb Stewart, here's a link to his contact info: http://robbstewart.com/ Example of Robb's talent --- he designed and made Jim Self's FLUBA: http://www.jimself.com/fluba.html

Dave
_____________
Dr. David Rolf

[MikeMilnarik]

Sometimes it's simply that the valve wears in a way that is a result of how a player plays the instrument (how he/she puts the valves down). Another player may use an ever so slightly different angle and the valve doesn't respond the same way. I've found that this seems to happen often with the Yamaha 621 series (F or CC...no experience with the BBb). I *think* that it may be more common with the Yamaha 621's because the angle of the valve set is different from most other piston valve tubas. 99% of the time when I've seen this happen, it's the 1st valve that is hanging up.

Of course, it very well could be the valve guide. But if you feel that there was no problem with the valves when you had it, and this started happening when the new owner received it - probably not coincidental. Probably has to do with how the new person is playing the horn.

Some time may be needed for the new player to get used to the horn, and for the valve to wear a little to how they play.

The repair people mentioned may have something that can help smooth the transition so that it doesn't hang up as much.

I hope this helps a little.

Mike Milnarik

[Tom Holtz]

Sometimes it's simply that the valve wears in a way that is a result of how a player plays the instrument (how he/she puts the valves down). Another player may use an ever so slightly different angle and the valve doesn't respond the same way. I've found that this seems to happen often with the Yamaha 621 series (F or CC...no experience with the BBb). I *think* that it may be more common with the Yamaha 621's because the angle of the valve set is different from most other piston valve tubas

My 621 F was the same way when I got it. We're over it now.

Since the 621 valve cluster isn't the most ergonomic (as discussed in many other threads) the angle at which the new owner's index finger arrives at the valve may be very different from the previous owner's finger. There was a definite "breaking-in" period for me--don't remember how long it took, but it wasn't bad. Now, when someone else picks up my 621 and starts playing, it's not uncommon for one of the valves to hang repeatedly and then behave perfectly for me when I play a moment later.

Also, if my 621 is indicative of the series, those valves are really tight. I give mine a good bath regularly, because there's no room for any crud in those valves. Even after they're broken in to the new owner's hand position, they'll still need cleaning. Tell the new owner to give it the full cleaning (as also discussed in many other threads) before racing to the shop.

It could be the valve guides... ditto Mike Milarnik on the valve guides.

Ditto Rick Denney on the newer guides, too. No problems with mine.

[Rick Denney]

Also, if my 621 is indicative of the series, those valves are really tight.

Mine were super-tight, too. It caused problems when playing outdoors in hot Texas weather at Fiesta Texas. My repair guy and I lapped them in a bit to loosen them up just a bit, and that helped. I figured that the OP's 621 was well enough broken in so that it wouldn't be a problem, but it's worth mentioning.

Rick "whose 621 valves are no looser now, 16 years later" Denney

[tbn.al]

I never dreamed I would get so much good info on a horn I no longer own. It's funny though, I played this horn a bunch for 3 months trying desperately to learn to like it. I never had any of the valves even drag a little. I don't think I even oiled the valves for 6 weeks after Matt sent it to me, but I always played in a 70 degree room and never outside. Seriously the valve speed was right up there with the response as outstanding attributes of the horn. I really appreciate your comments trying to help me and my buyer. I'm beginning to think it's a hand position thing. That is a really funky hand position. I was having a bit of trouble getting comfortable with it at first until I looked at some photos of Daellenbach playing. I noticed he holds his right elbow out away from his body and kind of high. I got a pillow and put it under my right armpit for a few days and never had any more problems with the hand position.

[Dylan King]

Boy, I must have some strange hands. I'm 6'4" and haven't noticed any discomfort from the valves on my 621. My other horn horn, being a Yorkbrunner is the exact opposite of the 621 in size, and I am just as comfortable with the valves on it.

Although I have noticed that the first valve sticks ever so often on the 621. I find when that happens all it needs is a little blast of my homemade oil and she's good to go.

The valves on this horn are quite tight. They seem to need fresh oil about twice as often as I need to put oil on the Hirsbrunner valves.

[Rick Denney]

Boy, I must have some strange hands.

If so, mine are strange, too. I've never had the slightest issue with hand position on the Yamaha. Neither have I ever had any problem with the hand position on my Miraphone, Holton, or B&S.

The York Master, on the other hand, needs an elbow closer to the chair and I had to extend the fourth-valve button to reach my pinky. In that case, I think I'm too tall for the instrument--my arm approaches the valves from too high an angle. It's certainly not hand size--I can palm a basketball.

Rick "big hands, big feet" Denney

[ScotGJ]

When I first got my ybb621 I had some hang up problems. Two things made it go away.

First, I had to tweak my hand position until I got a centered, straight down push on each valve cap (no lateral torque what-so-ever).

Second, I switched to Hetman's oil.

Now the valves are great.

[Dan Schultz]

Aside from there being obvious mechanical problems, the first thing I would suspect is simply a bit of lint in the valve... possibly from the felt bumpers. Most Yamaha pistons are fit very tight and the slightest bit of dirt can cause problems. Oil often and don't be afraid to 'pour it on'. Everyone's chemistry is different and I've seen Yamaha horns cause problems in one person's hands and not others. Make sure the leadpipe is clean.

[Tom Holtz]

Seriously the valve speed was right up there with the response as outstanding attributes of the horn.

My 621 valves are much quicker than I can competently operate them. There's no issues there. Clean and oiled, it's the fastest valve cluster in my possession.

[jbaylies]

bump because I feel like sharing some info

I traded my Rudolf Meinl 3/4 CC to MikeMilnarik for a YBB-621 + some $. It took me a good year to get used to the horn, and the first valve did stick a lot, but I think I played it enough to wear it down a smidge, and now it never sticks unless I force it to do so. It's nearly the prefect horn for me (aside from some slight ergonomic issues), and it's super easy to carry around, which is great for rehearsals and gigs that I don't want to lug a sousaphone to. I've even gotten a couple "nods of approval" just due to the low register tone & volume. Thanks for the trade, Mike

PS: Once I set the tuba (in its soft case) down on the floor of an art gallery, and someone thought it was a beanbag chair or something and sat directly on the valves. I noticed within 15 seconds or so and implored them to stand up. The tuba was surprisingly completely fine. Admittedly, they were not very heavy. Maybe ~120 lbs.

[Beyond16]

I bought these a while back and they appear to be genuine OEM replacements:
https://mouthpieceexpress.com/catalog/p ... s_id=23649

[GeoffC_UK]

See other comments.... yes, it could be the guide...... yes, it could be irregular wear caused by how the player depresses the piston..... yes, it may need a tech to look it over or........ it may be the age of the horn, with older ones needing a different oil.

If an older instrument try: remove piston; wipe valve dry with a lint-free cloth, then rinse under running warm (not hot) water followed by drying with a lint-free cloth, again. Apply a single line of valve oil down the length of the valve. - Use oil suitable for older horns (eg. Yamaha Vintage Oil). Return valve to casing and spin/ move up & down a couple of times before seating valve key in its slot and screwing the cap down. Repeatedly depress the valve a dozen of so times before moving on to the next value. - Best to do one valve at a time to avoid mixing them up.

May not be the root of your problem, but worth considering.

Geoff

[arpthark]

Considering this post is from 2007, I'd say the OP has figured it out by now.