YEP842 Valve Problems

[Daniel8802]

So just curious. After I oiled my valves, I spin them around to make sure the whole inside gets some. I've noticed lately that it feels like they are rubbing and not gliding as smoothly as they should. Is there something that would be causing this, or is it normal?

Also, on my 3rd valve I haven't unscrwed the valve button much, but when I did the other day to check something I noticed that the whole stem of the valve moved and became loose. What can I do to tighten this, or repair it so that only the button comes loose like the other buttons?

Finally, just curious what you all use for valve oil? I am currently using Al Cass fast valve oil, but it doesn't seem like its giving me the results that it should be. If you have any recommendations that would be great. Thanks!!

[imperialbari]

If it only is the rotational spin, which has slowed down, then the valve situation actually may have improved.

No valves can be made absolutely tight. Some, like Dave Werden, think that the roughness of new horns comes from the lack of valve tightness. He, bloke, and others have written upon the patina of the inner valve casing surfaces being the factor which compensates for the production shortcomings.

The patina creates a crystalline mesh or coral reef, which gives a good foundation for the thicker valve oil residues, when the more fluctious components have evaporated. Combined with the emulsion of valve oil and body based fluids this gives the bed of small roller balls on which the pistons glide.

This doesn't sound very delicious, but if one cleanes casings and pistons thoroughly (that is removing all fluids and fats), then you will experience some very scratchy valves. After such cleaning you will experience the valves needing a larger amount of oil, because the porous patina layer has to be filled again before any oil will be left for the roller ball layer. This isn't a warning against cleaning, either. I just want to point towards a proper balance.

Ideally the pistons and casings should be perfectly round. They aren't, and their imperfections don't even mactch each other. What you experience is that the layer of patina makes the imperfections match. Even so mutch that the spinning around the axis becomes slower. Be happy!

Your experiences with the valve stem is about the threading of the button being more sticky than the one on top of the piston. The wise guys of this board will tell you the names of sunstances from bottles or cans, which will make the right threading most sticky. If I want a threading stick, then i take a tiny bit of thin plastic from a bag intended for freezing food and wrap it around the male thread before mounting it.

I have had the same experiences as you, only not with an 842, but with my 12 years old YEP-641, which is not for sale. The very tight Yamaha pistons have annoyed me. But then bloke told about Blue Juice. I don't like its stink, but it makes the valves work.

My tech English is limited, but hopefully the main message comes through.

Klaus Smedegaard Bjerre

[Rick F]

Daniel,

As Klaus says, the valve stem loosening before the valve button does sometimes happen. Just be careful not to loosen the stem too much or your valve guide could lose its alignment (see drawing below). The stem is what holds down the valve guide into its alignment hole on top of the valve. The few times I've had the stem loosen before the finger button, I would hold the valve stem with thumb and finger while twisting loose the valve button. It usually comes loose.

For valve oil I use Hetman Light Piston Oil. This light oil is excellent for the tight valve clearance the Yamaha horns have. I see you live in NJ. Not sure how far you are from Dillon's, but they carry Hetman's. I also have a YEP-641. Although it's almost 15 years old, the valves are in excellent shape with tight clearances.

[Dan Schultz]

.....Just be careful not to loosen the stem too much or your valve guide could lose its alignment ...... The stem is what holds down the valve guide into its alignment hole on top of the valve....

Daniel... if you should loosen the stem to the point where it no longer holds the valve guide down, please be aware that the pin on the bottom of the valve guide fits into the SMALLER hole in the top of the piston. The larger hole is a vent. It's possible to locate the guide in the wrong hole... which will severely throw off your piston alignment.

[MikeMason]

I tell my band directors "make sure you can see the number of the valve(1-4).If you can't,it means you've got the valve guide pin in the wrong hole." Yes,I've got a "wrong hole" joke ready,but I'm going to refrain...

[J.c. Sherman]

I've given many folks one bit of advice for Yamaha piston instruments. All say valves are sluggish. I tell all of them, use the Yamaha Valve Oil that came with it. Everyone is happy.

Seriously, give it a try. Wipe off the valve, use the yameroil, and I'll bet things improve.

J.c.S. (who has a bottle of Yammieoil stuck in the tubing of his 621 F at all times).

[JTJ]

I agree with j.c.s. I have an 842, previously had a 642, and in both cases I have got the best results using the Yamaha valve oil which shipped with the horn. I buy them by the dozen from WWBW.

John

[XtremeEuph]

Hey there I have the same horn....exact same problem. Im telling myself it needs a serious clean though its not that terribly bad, its extremely hard to turn the valve in the casing especially when my hands have some oil on them. But, the valve action up and down while playing is still very smooth which is all that matters right?