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Valve Compression - King 1241/2341?

Posted: Sun Mar 06, 2016 12:35 am
by TNID
Hi all, I bought this horn on eBay and received it on Thursday. The horn was listed as a 1241, but after on a bit of research, it appears I may actually have a very early 2341 made before the 3rd valve slide was straightened. Also, the leadpipe doesn't wrap quite as far around the bell as I remember on the mid-1980's 2341 horns I've played in the past. I'm not 100% certain either way, but here's my real concern:

When inspecting the horn, I found that there was no "pop" when a valve slide is pulled before depressing the piston except for a very slight sound on the 4th valve. Also, when pushing slides back in, they don't get harder to push as they go in, leading me to believe that there is little to no compression available in the valves. This is the case on all 4 valves. Every slide on the horn moves freely with no hang-ups.

So I guess I'm looking for suggestions at this point. The eBay listing said "Good valve compression." Is there a better or more proper way to check this out?

I'd rather keep the horn if feasible, so what is a ballpark price estimate on a valve rebuild if necessary?

Thanks for any and all information. Here are some pictures...

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Re: Valve Compression - King 1241/2341?

Posted: Sun Mar 06, 2016 12:53 am
by Donn
Have you played it?

I'm no expert, just some clown with ideas, but anyway, my suggestions kind of follow what we've been saying to the 36J guy who suspects valve leakage:

1. Play it for a while. I mean, more than just a couple minutes, because I think after going a while unplayed, sometimes a tuba needs to be warmed up a bit more. If it sounds great, then congratulations.

2. If you aren't sure you like how it's playing, goop up the valves with really thick oil, like mineral oil or even motor oil.

3. Play it again (play something that doesn't use the valves more than you need to, to compare against 2, because they'll be nearly glued in place.) If it plays better then, you have leaky valves.

4. Don't worry about measuring valve compression, that's more for internal combustion engines. I actually get a faint pop from the 1st valve on my 1240, but you don't want my rusty old pistons.

Re: Valve Compression - King 1241/2341?

Posted: Sun Mar 06, 2016 1:02 am
by Ken Crawford
I had new MAW valves lapped into a 2341 and the slides didn't pop much before or after. I don't know if it's a proper way to check for leaks, but you can pull out your main tuning slide, plug the valve section side with your finger and blow into your mouthpiece. You just checked the entire valve section for leakage.

Re: Valve Compression - King 1241/2341?

Posted: Sun Mar 06, 2016 7:55 am
by Sam Gnagey
Bloke nails it again! No horn plays to its potential with leaky valves. I have two valve sections ready to send to Anderson for the complete job. It is a big job getting the valve section off and back on, but it's worth it to have the horn playing great.

Re: Valve Compression - King 1241/2341?

Posted: Sun Mar 06, 2016 12:55 pm
by Sam Gnagey
1 and 3 pistons are interchangeable. 4 and 2 don't quite line up.

Re: Valve Compression - King 1241/2341?

Posted: Sun Mar 06, 2016 1:39 pm
by TNID
Thanks for all the replies. On the method of cleaning, I had been wondering about that myself, as there is a somewhat strong chemical-ish smell to the horn. I don't believe the pistons have been re-plated because there are some small spots of wear near the top and bottom of them. Other than that, it appears they all have pretty even wear. I'll try to get some pictures in natural light this afternoon with a "real" camera instead of my phone.

On the subject of a full valve rebuild, what might be a reasonable cost estimate for that? I understand it may not be cheap, but I did buy the horn willing to spend some extra getting it back shipshape.

I have not yet played the horn, but was able to dig up an old Bach Mega Tone 7 that's been in the drawer for about a decade, so I'll try it out today. There's a new G&W mouthpiece on order, but not here yet.

The pistons have just minimal coating of oil now, so I'll try adding some Blue Juice and see how things go.

And on the topic of compression being more for internal combustion engines, I certainly agree what we're talking about is more of a sealing matter. I'm more of an engine guy myself, however, "compression" seems to be the more popular way of putting it. :)

Anyway, I'll run the horn through it's paces a little later and try to report back with some more pictures. :tuba:

Re: Valve Compression - King 1241/2341?

Posted: Sun Mar 06, 2016 1:49 pm
by Donn
TNID wrote:And on the topic of compression being more for internal combustion engines, I certainly agree what we're talking about is more of a sealing matter. I'm more of an engine guy myself, however, "compression" seems to be the more popular way of putting it.
Sure, the point is just that with a motor, you care. With a tuba, maybe not so much.

Re: Valve Compression - King 1241/2341?

Posted: Sun Mar 06, 2016 8:03 pm
by Dan Schultz
The port 'footprints' on the inside of the casings and the fact that the inside of the casings are very shiny looks really odd to me. I'd like to run a scope down that horn and see exactly what's going on. Are you close to Southern Indiana?

Re: Valve Compression - King 1241/2341?

Posted: Sat Mar 12, 2016 12:54 pm
by TNID
I'm a few hundred miles away. I've had trouble getting better pictures inside of the casings, but I think part of the pink look in the earlier photos was due to the flashlight I was using at the time.

Unfortunately it took me a lot longer than expected to be able to get pictures outside during daylight hours, but here they are:

http://s272.photobucket.com/user/thenam ... ing%20Tuba

Having played the horn now, I'm not sure about it. The slotting seems imprecise and the apparent lack of sealing with the valves well oiled is concerning. :|

Re: Valve Compression - King 1241/2341?

Posted: Sat Mar 12, 2016 1:29 pm
by The Big Ben
The $1000 amount Bloke mentioned is the price I paid for a first class valve rebuild of my Olds 099-4v. (boring/honing bores, plating and sizing pistons, fabricating and fitting stronger valve stems- the valve stem is one of the weak points of these Olds instruments) I've allowed other players to have a toot and they usually say, "Wow. Nice valves". Very much worth the price.

Re: Valve Compression - King 1241/2341?

Posted: Sat Mar 12, 2016 1:35 pm
by The Big Ben
TNID wrote:Having played the horn now, I'm not sure about it. The slotting seems imprecise and the apparent lack of sealing with the valves well oiled is concerning. :|
If you can send the tuba back, I would suggest sending it back. You will have to pay the shipping. ($100? Hope you saved the box it was sent in.) After you spent your hard earned money, you should be satisfied with your purchase. Taking it down to TT's will cost you the amount it would cost to ship it back to the seller. Plus whatever it would cost to make the valves work right.

It's a nice looking horn and in silver but, believe me, another one will come along. H.N. White/King/The Borg made lots and lots of them.

Re: Valve Compression - King 1241/2341?

Posted: Sat Mar 12, 2016 6:51 pm
by Ken Crawford
For the price you paid on ebay, and spending the $1000 to get the valve section redone, you still will have gotten a good deal on the horn. Fix it. You bought it for $1300, add $1500 and you've got a really nice horn for $2800.

Re: Valve Compression - King 1241/2341?

Posted: Sat Mar 12, 2016 9:49 pm
by Donn
So it has been decided that the valve section needs to be rebuilt? Even though, as I read it, it doesn't play better with thick oil in the valves?

Re: Valve Compression - King 1241/2341?

Posted: Sat Mar 12, 2016 10:44 pm
by Ken Crawford
Donn wrote:So it has been decided that the valve section needs to be rebuilt? Even though, as I read it, it doesn't play better with thick oil in the valves?
Well of course he should have it looked at by a professional before doing anything.

Re: Valve Compression - King 1241/2341?

Posted: Sun Mar 13, 2016 11:13 am
by Dan Schultz
kmorgancraw wrote:
Donn wrote:So it has been decided that the valve section needs to be rebuilt? Even though, as I read it, it doesn't play better with thick oil in the valves?
Well of course he should have it looked at by a professional before doing anything.
+1. I'm betting that the pisons are undersized but it could be something else like a leak or wrong piston. Actually... there isn't much seal sutface between the piston ports so it could be a combination of several things including simple stuff like vertical alignment.

Re: Valve Compression - King 1241/2341?

Posted: Wed Mar 16, 2016 6:56 am
by cjk
The valves may just be in the wrong casings.
The alignment may be really off.