Wurlitzer valves are normally set at around .035" valve travel for a
band organ.  There are instances that more travel is needed, depending
on the size of pneumatic.  Too much gap will lead to a sluggish valve
(slow response).  Too small a gap will not let enough air back into the
pneumatic, and the repetition will be slow.

There are a couple of ways you can adjust these.  If you put light
pressure on the adjusting screw with your finger, you can take a small
screwdriver and lightly turn the valve up or down, making sure to keep
the screwdriver close to the threads, so as not to damage the leather
where it seats on the valve.

Another way is to apply vacuum to the bottom port of the valve, after
you cap off the nipple.  This will keep the valve down, so you can
adjust the top valve clearance.  This is the best way to get a true
valve clearance, because the vacuum compresses the leather the same as
if the organ was on.  In some cases, if you don't use this method, you
will notice that, after setting the valve and installing it, when the
band organ turns on you might still have too much of a gap.

Being that I have built thousands of valves over the years, I made a
valve testing station.  I can clamp a valve into it and, by means of a
dial caliper finger that rests on top of the valve screw, I can measure
the valve travel to the thousands of an inch.  This way all valves are
set alike.

If any reader here wishes, you can send me your valves, and I can set
them for a small charge.  In some cases I will not charge anything,
except shipping.  I just don't want someone sending me three hundred
vales, expecting it to be done for free.  If anyone has any questions,
please don't hesitate to contact me.

Robert Loeffler
Deland, Florida
www.robertsmusicalrestorations.com