I just got a few new flemish strings for my recurve, and the top loop is larger than I have used before. To me it seems to be causing the string to rattle after the shot, maybe because its not as snug on the top. Any suggestions as to how to remedy that? I thought maybe I could twist it tighter, but that doesn't work.

The only way to remedy loop size is to untwist it and twist it back up. I wouldn't recommend this unless you've built a flemish string before. The overall length of the string will change a little as well, but can be avoided by adjusting the length of fold over of the tag ends. May sound confusing, but it's pretty simple once you learn.

I have several Flemish strings, they are not all identical.  Some of my top loops are smaller than I would like.  

I have a recurve too.  I made wool yarn puff ball silencers and I have one where the string goes into each limb pocket.  I think it helps.  Maybe try that.

You can serve the loops to make them smaller.

You are better off with the loop slightly large on a recurve limb, or any bow limb actually, than having it too tight... a Flemish loop that is too tight can bind and cause problems with the limb tracking straight depending on the string notches.

What i would try first is rotating the loop 180 degrees and make sure it's laying down flat..... if the loop is huge... Like black velvet said, you can serve it and make it a bit smaller.

Dental floss and a clove hitch.

Thanks guys! I hadn't thought of dental floss or serving it. Perfect.

I can't say that I know how to fix it,but when I order them from Oliverstacy that is Josh Sowerby he has you measure down from the tips. I think it was four inches on the recurve and three on the longbow he said this helps with getting a good loop size.