need some help

[peter p]

Can be the brace height.
I had an Exomax that did the same thing.
Every-time the string stretched the poi would change and it would shoot higher.

[wabi]

Brace height isn't going to change arrow velocity more than a few fps. Not enough to have much effect on accuracy.

I'd say a new scope will cure the problem (for a while).

BTW -
If my Leupold fails I'm going back to open sights or give a red-dot type sight a try.

[Pydpiper]

Brace height isn't going to change arrow velocity more than a few fps. Not enough to have much effect on accuracy.

I beg to differ, the OP said they are shooting at 40 yards, a "few" FPS at 40 yards can result in a miss.
The scope has already been changed, with no improvement.

[MADMAX2]

If it is because of string creep would putting a new string on help?

[Pydpiper]

If it is because of string creep would putting a new string on help?

Had to read between the lines, he made no mention of an upgraded string, so I had to assume it is the factory Dacron. Then he said he had the bow cocked for two straight days, that is enough to make a crucial change in POI if the string wasn't checked between hunts.
For your question, yes. If he upgraded to a different material, one that was not so prone to creeping (Boo string or FFF.)
than he would not have to give the string the same amount of attention. It would still need monitoring, but not nearly as much.
But, the Dacron is just fine for any situation, it just needs to be watched and adjusted when necessary. If that string was put on new and was above the highest line on the bow as most people report they are when new, then sat cocked for two days the string may have altered the POI. I think that a closely monitored brace height will resolve all the issues for the shooter. After checking for loose hardware of course.

[secret]

If it does turn out to be a brace height issue....Maybee Excalibur should discontinue the dacron string and only put fff strings on all models!!!! This way people wont think less of their product. Im very lucky the man who i bought mine from who knew this and put a ff string on new...and gave me Gold Tip Lazer 2 with brass inserts and upgraded my scope to a Lumi-zone.

[sipsey]

It's my understanding that a dry fire with the factory dacron string can usually be absorbed by the limbs---Quite a few of us, I mean some , people take a while to establish a good habit of cock, safety, bolt, safety, fire---Starting out with the faster strings is a recipe for cracked limbs, for some.

A very integral part of shooting Xcal bows is checking string tiller untill it becomes second nature. The moment one takes any aspect of of any component for granted, is usually after a nice target is missed for no apparent reason.

[peter p]

When I had my Exomax, I had the FFF string and that string stretched more than the factory dacron that I have on my Exocet 200. Actually I can only get 1 1/4 inch brace height with no twists in the dacron string on the 200. Seems like the string is a little short.
Anyway when I had my Exomax with the FFF string, that string stretched alot. It probably stretched 2 inches.
Every second time I had it out I would have to shorten it 1/4". I took a target to the field with me everytime I went hunting to check poi after I adjusted the string.
If I left it with the shorter brace height the poi was higher.

[Pydpiper]

It's odd that a Fast flight would continue to creep at that rate. All strings will creep a bit but some are prone to slow down faster than others, Fastflight is one of them. It will still creep throughout it's useful life, but typically slower than Dacron.
Dacron is like a rubber band, it comes with the bow because it is the most forgiving of strings, it is also the slowest. Dacron will never stop creeping. If you ever dry fire the bow, it is a great protection against damage.
I monitor my string with digital calipers, I take the whole accuracy thing pretty serious. My string has not moved in over a year, and I shoot almost every day.
I don't see Excalibur discontinuing the Dacron string anytime soon, mostly because it is not their material to discontinue. Dacron probably saves them countless money in warranty repairs. It is an excellent string but it requires a bit more attention from the user.