Harken 7413.10 MKIV Jib Reefing & Furling built after Feb. 2009 - Manual (Page 29)

Commissioning—Unit 3, 4 Halyard Wrap/Prevent Halyard Wrap
MKIV units 3, 4 29
1. Halyard swivel should be within top 100 – 152 mm (4 – 6") of foil unless
a halyard restrainer is used.
2. Halyard must pull slightly to rear (8 – 10°).
3. Halyard must be snug, but not too tight.
Test furler at dock. However, if water is smooth, an incorrect lead angle may not be
apparent. Halyard wraps usually occur in wave action when lead angle is not
correct. The 8 – 10° angle shown at right is critical.
Prevent Halyard Wraps
To prevent wraps, the halyard must exert a slight pull to the rear. This allows the foils to turn while halyard remains stationary.
WARNING! Sail must be fitted to foil length before using
to prevent halyard wraps and possible headstay loss.
Halyard Wraps
The most serious problem with furling systems occurs when the jib halyard
wraps around the headstay foil. Halyard wraps will keep you from furling
or unfurling and may cause serious damage to the unit and the halyard.
WARNING! In severe cases, a halyard wrap can cause loss
of control of boat and/or headstay can break suddenly.
Make sure halyard is clear of top foil before using system.
A professional rigger must carefully inspect the masthead area using a secure hoisting method. Inform rigger that there has been
a halyard wrap so he can avoid an accident by relying on standing rigging or halyards. Inspection must be done while rigger is
suspended from a separate crane, or mast must be lowered to perform inspection. Some professionals may rig a new line through
internal masthead sheaves to serve as a temporary headstay to hold mast in place. Wire, rod rigging, terminals, toggles, clevis pins
or cotter pins must be inspected and replaced if they show any signs of damage.
WARNING! Do not go aloft on boat’s halyards if there has been a halyard wrap. Do not use boat. Damage to halyard,
headstay, stay terminals, or connections as a result of a halyard wrap can cause these parts to break suddenly, causing
the mast to fall while person is aloft. Sailing or motoring with boat after a wrap can result in the headstay breaking and
mast falling. Before using boat, have a professional rigger inspect and replace parts as necessary using following methods.
If Halyard Wraps
If halyard wraps, do not force unit to turn. Attempt to open sail by carefully
furling in and out a little at a time. If sail unfurls, lower it by releasing jib
halyard. Severe halyard wraps can only be cleared by a professional going
aloft and freeing halyard.
If sail will not furl or unfurl, try to remove jib sheets and manually wrap
sail around headstay.
8 – 10°