25.5 Shroud tension
Got a 25.5 myself. There shouldn't be any slack. A few things I've learned: -Get a Loos gauge, worth the money and most helpful. -We have 5/32 wire, rated at 2800 lbs. You do not want to exceed 25% of that number in any event. -Start with your mast plumb (make sure), with just a bit of tension in all shrouds, forestay and backstay. -Tighten forestay till about halfway point in turnbuckle threads. -Go to your uppers. Tighten an even number of turns on each side till you get about 1 inch or so of pre-bend(forward bow) in the mast. Sight up the mast to check this. Tension here will be about 18-20% (500/560 lbs on Loos gauge). -Go to your lowers. Tighten evenly till firm, but you do not want to undo the pre-bend you just put in the mast. Loos gauge tension should be about 10 to 12% (280/330lbs). -Check your forestay tension just to make sure it's not exceeding 20%, give or take. -Go to your backstay and tighten till firm, around 10-12% again. The backstay should be firm, but you don't want it taking over the job the uppers are doing. -Sight up your mast to check side to side plumb, both in the middle and at the top. Sight up the mainsail luff groove for this. All these numbers and procedures are a combination of info from Hunter and Brian Toss Rigging. On our rigs, the mast tension is really created by the forestay against the aft-pull of the uppers through the swept-back spreaders. The lowers are a check to keep the mid-mast straight. The backstay has little effect here, until you sail downwind where there is more tension on it. The 1 inch pre-bend is important for mainsail shape/performance, and is in the Hunter manual for this boat. You can see that the Loos gauge is helpful. -This is the basic tune. Anything I've read will tell you to go sailing in about 10-12kts at this point, and check for mast straightness, how much slack you get in the lower leeward shrouds, etc. I'd recommend Brion Toss's book, or whatever you can get that'll give you an idea of how to diagnose what you see under sail. Good luck!
