Tuning the rigging
I have an 86 O'Day 222 with a CDI FF-2 roller furler. I use an old Loos Gauge that I've had for a number of years to tune my rigging. First of all, if you know your wire diameter all you need to do is pick a number which is a happy medium for the gauge thickness of your upper stays, and make your lower stays a little slack. I've been setting my upper stays at #30 and my lower stays at 25. My upper stays 1/8" and my lower stays 5/32". I could set set my stays a little tighter because I have O'Day 25 chain plates, but these numbers seem to work OK for me. I have a fractional rig so there's no way that I'm going to take all the slack out of my furler without bending my mast back, so I don't try. I have a Johnson Handy-Lock on my back stay, so I can adjust it anytime I need to. So this is what I go by for the range of various tensions that apply to my rigging thickness. It's probably a good idea to lay on your back on the companionway hatch and sight up the mast to make sure it's straight, but if you use the same numbers for your stays, it has to be straight.Joe