Hi.I just pulled the "Air Cleaner Case" out of my 1973 DT3.  There are (were) two foam pads glued to the outside of the case . . . one on the right side and one on the back (colored blue on the diagram):

After thirty-eight years, the foam had turned to dust and there was little more than the original glue still remaining.  I'd like to glue new foam pads onto the case, but I don't know where to start.  Does anyone have any idea what type of foam it was, or how thick it was?  The old glue was a chore to remove, but several applications of acetone finally did the trick.  Anyone have any idea what kind of glue Yamaha used?
Thanks for your help.
Mark

Hi Mark,
i just bought a sheet of adhesive sponge rubber on Ebay, 3mm thick.
Cut the size you need and stick it

That's the perfect solution.  I just ordered a sheet of adhesive-backed black neoprene.  Not exactly OEM, but neoprene will provide better cushioning and will be a more durable material.  Thanks very much for the suggestion!
Mark