Steveh is right, any more than 4 turns and you run the risk of the spring becoming 'coil bound' bottoming out on itself (depending on weight/travel) before the shock bottoms out. This will quickly damage your shock, check your spring rate to see if you need a stiffer one to get the desired sag (25 to 33% of full travel usually)
I am 90kgs in my kit so according to spring calculators I need a 450lb spring with two full turns, which according to Fox is the max.
TF say I need less then that though but still a 450 spring.
When I measure the current sag its a bit more than 30% and ideally I want it at a bit below 30%.
The problem is I have tendon problems in my left thumb and can't grip the ring well enough to turn it once its engaged with the pre-load ring. Hence I need a spanner.