Two action questions

[Newton Hunt]

> This only happens in the lower middle section. Any other ideas ??? I will keep you informed if I find out any thing

The front screws holding the stack in place need to be tightened LAST
because they are toed in at an angle.  If the screw is not all the way
down and secure you can get this effect.  Check the screws holding the
hammer rail to the bracket at this location.  Check that the toe
blocks (the blocks the action is screwed to) are securely glued down
and the screws are tight.  Check that the glue joints holding the key
frame together are secure.  If this is an old Yamaha G-3 instead of a
C-3 there is a wooden hammer rest rail that could be being hit by a
wippen from underneath or by a rep lever button which could cause your
phenomena.

> couple horendously informative posts.

Well I have been accused of being horrendous before but not as
horrendously informative.  New experience for me.

>  Down 75 grams (heavy) up between 18 and 24.

These numbers place this action way, way out in the middle of space. 
I am inclined to think, without further numbers, that you have a case
of grossly over weight hammers.  Anytime someone makes a change in
action parts there is a real potential for problems.  Get all your
numbers together and we can make some more informed decisions.  Since
you are at a university you can go to the physics or chemistry
departments and borrow a digital scale which can measure to .1 gm. 
Digital because the pan does not move much.  With this tool we can
know exactly what the problem is and how best to go about fixing it. 
Knowledge is power and in this case the power to correct earlier
problems.

I am looking forward to seeing more information.

		Newton