How do you tell if one is warped? I was digging around today and found my dad's old 66#. But something seems off when I draw it...

Brace the bow and then sight down each limb. If a limb tip leans one way or the other, it is twisted or warped (unless, you are talking about a self-bow - that's a whole different story.)

With the bow strung set a limb tip on the floor and sight down the string to see if you can detect a twist. Rotate the bow and sight down the string with the other limb tip on the floor. If it is twisted you should be able to tell which limb is out of alignment. With the bow still strung try twisting the twisted limb in the opposite direction rather hard. Do this a few times and see if it will go back into alignment and stay aligned once drawn. Leave it strung and hanging by the string a few days after doing this.

If you can't get the twisted limb to go back into place doing this you may need to warm the limb up with warm tap water or a hair dryer taking caution not to over heat it. There was a good article in TBM a few issues ago on using the warm water method.

First, if the limb is twisted much it may come unstrung faster than you say, ouch. First inspect the bow for factures, cracks etc., then in good light, set one limb (unstrung) with back up on a table, hold the other limb and sight down the limb, both tips should be point up. If the tips do not line up and seem to be pointing in a different direction, you probably have a twist limb.

I bought an older Bear Kodiak that had a slight twist in the upper limb, and a double twist in the lower limb.  If I had strung it without checking, it would have come unstrung. Bad things happen if a recurve does that.

Once I was able to confirm the twist, location and direction, I used a heat gun that puts out from 200 - 1100 degrees.  With it set at about half way, move the heat gun, back and forth over the area to be twisted. If you get it too hot, the glue may soften. If the bow glued at 175 degrees, the temperature from a heat gun could surpass that, and you would have a problem. It should be quite warm to the touch. Do both sides. A heavy poundage bow, will be hard to twist enough to reset the limb.

If you do not feel confident in what you are doing, contact one of several guys on TG that do repair work.