I have a casting rod built with an ECSM reel seat, the locking collar does not stay tight. Any ideas how to tighten it up? Thanks

It’s probably broken. Many times when one tries to over tighten the hood, the the hood that good over the reel foot breaks away from the the threaded collar. If you don’t have a fore grip, it’s fairly easy to replace the hood unit with a new one. Basically, the hood is large enough to pass over most of the guides with the possible exception of the stripper itself. So just remove a guide or two, remove the old hood and replace with a new one. Rewrap and finish the guides and you are good to go. If you need a hood let me know and I will send you one. If you have a fore grip then a little more work involved.
Norm

No foregrip I’ll look more at it in the next day or two. Thanks for the offer.