Well, I freshened all my taps this morning, some had sap running and some didn't....there wasn't a noticeable difference in the wood or type of holes between sap producers and non sap producers other than the lack of sap, colour, wood condition, etc were all the same. I did notice that the older trees were inconsistent in producing sap (some trees has one or two taps producing and one or two that didn't while others were completely dry); all the younger trees were producing something. However, the trees that produced last year are substantially down in volume as well so the 'new' old trees I tapped may not be the culprit.

With that being said, if the non runners stay dry my 103 taps becomes closer to 50 or so....that would be unfortunate.

Thanks for the tip Dscanuck and fingers crossed that was the issue...