Clean/Inspect 31
Replace Line 31
Storage/Remove Furler 31
Troubleshoot 32
Warranty 32
Appendix 33–34
Please read these instructions carefully before installing, servicing, or operating the equipment.
This manual may be modified without notice. See: www.harken.com/manuals for updated versions.
PLEASE SAVE THESE INSTRUCTIONS
Page 2
Safety Precautions/Parts Description
Introduction
This manual gives technical information on installation and service. This information is destined exclusively for
specialized personnel or expert users. Installation, disassembling, and reassembling by personnel who are not
experts may cause serious damage to property or injury to users and those in the vicinity of the product. If you
do not understand an instruction contact Harken.
The user must have appropriate training in order to use this product.
Harken accepts no responsibility for damage or harm caused by not observing the safety requirements and
instructions in this manual. See limited warranty, general warnings, and instructions in www.harken.com/manuals.
Purpose
®
Harken
Jib Reefing and Furling is designed for rolling sails on sailboats to reduce sail size or to completely roll
so wind has little effect on the sail. Use of this product for other than normal sailboat applications is not covered
by the limited warranty.
Safety Precautions
WARNING! This symbol alerts you to potential hazards that may kill or hurt you and others
if you don't follow instructions. The message will tell you how to reduce the
chance of injury.
CAUTION! This symbol alerts you to potential hazards that may hurt you and others if
you do not follow instructions. The message will tell you how to reduce the
chance of injury.
WARNING! Strictly follow all instructions to avoid potential
hazards that may kill or hurt you and others. See www.harken.com/
manuals for general warnings and instructions.
5
2
1
4
3
8
9
7
6
Parts Descriptions
1) Toggle Assembly
2) Crosspin
3) Shackles
4) Drum Assembly
2 MKIV Unit 0
5) Foil Clamp
6) 2' (610 mm) Bottom Foil
7) Feeder
8) Connector Bushing
9) Bottom Connector
10) 7' (2.13 m) Foil
11) Connector Screws
12) Connector Wedge
13) Connector
14) Halyard Swivel
15) Trim Cap
16) Trim Cap Screws
Page 3
Preassembly Sizing Check
16
10
11
14
12
13
15
Online Product Registration
www.harken.com/FurlingWarranty
9
Size Check
1. Check headstay and clevis pin dimensions in chart below.
WARNING! Do not drill boat's chainplate or toggle. This may result in rig failure. Use the correct
size toggle and clevis pin.
2. Harken does not recommend drilling boat’s chainplate or toggle. In some cases bushings are available
to fit boats with smaller clevis pin sizes.
3. Will drum fit on bow? See page 6. If necessary, use an additional toggle to slightly raise unit.
Sizing Check
Unit Part No.DescriptionWire Sizes
5/32", 3/16", 7/32" 4 mm, 5 mm, 6 mm
7410.10MKIV Unit 0
-4, -64.37 mm, 5.03 mm
Toggle Part No.DescriptionChainplate Clevis Pin Size
7410.20 5/16Eye/jaw reversible5/16"7.9 mm
7410.20 3/8Eye/jaw reversible3/8"9.5 mm
7410.20 7/16Eye/jaw reversible7/16"11.1 mm
Rod Sizes
Chainplate Clevis Pin
MKIV Unit 0 3
Page 4
Presembly Parts
Drum Assembly
Bottom
Connector
Connectors
Halyard Swivel
2.5, 3, 5 mm
Hex Keys
7' (2.13 m)
Plastic
Connector
Wedges
Bow Shackles
Foils
Connector Bushings
Foil Screws
2' (610 mm)
Bottom Foil
Trim Cap
Trim Cap Screws
Feeder
Line
Main Components
Part No.QuantityDescription
HFG2901
H-399231
Drum assembly with foil clamp
Halyard swivel
Foils (Standard Package)
Part No.QuantityDescription
7410.305
7410.331
7'(2.13 m) Foil
2'(610 mm) Bottom foil
Line (Standard Package)
Part No.QuantityDescription
HFG59455' (16.7m)
7 mm double braid polyester
Tools
QuantityDescription
1 Each
4 MKIV Unit 0
2.5, 3, 5 mm Hex keys
Prefeeder
Red Loctite
®
Other Components
Part No.QuantityDescription
7410.314
7410.321
HFG2941
HFG2981
HFG3411
HFG6791
HFG6291
9471
H-397131
21103
HFG7392
HFG7251
6.5" (165 mm) Connector
10" (254 mm) Bottom Connector
Connector bushing set (10-H-42067/10-H-42068)
Plastic connector wedge set (12-H-39625)
Foil screw set (26-HFS1105)
Trim cap set (H-37335/H-37336)
Trim cap screw set (3-HFS1126)
Prefeeder
Feeder with screw and tab
6 mm Bow shackle
®
Red Loctite
Injector, 1 oz. 5200 Adhesive (HFG722)
(for foil screws)
5200
Adhesive
Injector
Page 5
Preassembly Rigging Parts Check/Tools
1. Harken toggle assembly required. Sold separately.
2. Mating turnbuckle components must be purchased separately.
3. Headstay may require cutting and shortening to fit Harken toggle.
Headstay may remain uncut by replacing lower stud of turnbuckle
with stud/eye thus eliminating extra toggle.
4. Rod rigging requires Harken rod adapter stud.
5. Order Harken 7404 Lead Block Kit. Fits 1" (25 mm) stanchions.
ALL UNITS
Harken Toggle
(Sold Separately)
ROD RIGGING
Harken Rod Adapter
Stud Required
(Sold Separately)
WARNING! A stay that is old or
damaged may break suddenly,
causing an accident. Headstay
condition should be checked by a
professional rigger before reusing.
7404 Lead Block Kit
(Sold Separately)
7410.20 5/16
7410.20 3/8
7410.20 7/16
Eye/Jaw Toggle
Tools Required
7420 -4
7421 -6
Rod Adapter Stud
Includes 3 x 7403; 1 x 7401;
1 x 7402; 1 Horn Cleat
Adhesive Alert
MKIV Furlers are shipped with 3M 5200
adhesive. Use adhesives on dry connectors
3
5
and foils using the special injection system
described in the assembly section. Parts
may immediately be exposed to rain. Cure
1
4
12
is best at 70F (22C) with 50% humidity. Do
not apply at temperatures below 40F
(5C) and above 100 F (38C).
2
Although adhesive has not cured it will
remain in place on foil joints whether
8
10
6
15
they are left on the ground or raised up
on boat. Foils can be raised immediately
after assembly and sails fitted.
Note: A small amount of adhesive may
bulge out of injection ports. If possible
13
7
9
11
14
let system sit for a couple days before
sailing. If adhesive gets on sails remove
using acetone. For faster-curing adhesive,
1. Long tape measure 6. Side cutters11. Center punch
2. Short tape measure 7. Rat-tail file12. Rigging or black tape
3. Power drill 8. Hex keys (provided)13. Scissors
4. Drill bit – 1/8" (3 mm) 9. Slotted/Phillips screwdrivers14. Metal straight edge
5. Hacksaw10. Needle-nose pliers15. Hammer
MKIV Unit 0 5
purchase 4200 Fast Cure.
Note: Damaged foils can be repaired.
Use a hand-held propane torch to heat
joints until foils can be pulled apart.
Page 6
Preassembly Dimensions/Sailmaker's Instructions
Luff Length
Note offsets above and below the sail.
A shorter luff may be required if a halyard restrainer is necessary
(page 26) or a toggle or long toggle assembly is used to raise drum.
If the luff of sail is not long enough to put the halyard swivel near the
top of the headstay foil, a pendant must be added (see page 26).
33/4"
(96 mm)
61/4"
(158 mm)
Tack Setback
Note setback for the tack shackle and cut the sail accordingly.
Luff Tape Size
6
Unit 0 requires #6 (
/32" or 5 mm) luff tape.
Luff Tape Length
Cut off top of luff tape so it is 18" to 24" (450 to 600 mm) below head of
sail. This allows head to lag behind rest of sail to help flatten sail. It will
also help head to roll more smoothly.
Note feeder height and extend the bottom of the luff tape downwards so
it is below the feeder. This will prevent the luff tape from catching in the
feeder as the sail is lowered.
Tack and Head Shackles
Make sure tack and head shackles fit the
sail rings. The minimum inside dimensions
A
of the standard head and tack shackles are:
1
/16" (27 mm)
(A) 1
1
/2" (13 mm)
(B)
B
Sun Cover
Max
41"
(1041 mm)
Min
391/4"
(997 mm)
17/8"
(47 mm)
1
5
/2"
(140mm)
Max 25/16" (59 mm)
Min 2" (51 mm)
6 MKIV Unit 0
Max
83/8"
(213 mm)
Min
8"
(203 mm)
Sun cover may be installed on either side of the sail. However,
make sure you match other sails in the customer's inventory.
Page 7
Preassembly Toggle Deductions/Stay Into Foil Options
Use dimensions of Harken toggle below to build stay to correct length.
Tip: Turnbuckles should be 1/2 to 2/3 open to allow shortening for new wire stretch and for fine-tuning mast rake.
Clevis PinPin-to-Pin Length
5
/16" (7.9 mm)21/8" (54 mm)
3
/8" (9.5 mm)25/8" (66.5 mm)
7
/16" (11.1 mm)27/8" (73 mm)
Fork
Attachment
Crosspin
Tang
Attachment
For tang-down installations,
switch plugs to this position.
Crosspin
21/8" (54 mm)
25/8" (66.5 mm)
27/8" (73 mm)
Most boats have a chainplate with a single tang.
If boat has two plates forming a jaw, reverse
eye/jaw toggle so eye is down.
IMPORTANT! Remove black plastic caps and
install them so crosspin will be at 90 degrees
to lower clevis pin.
1. Swage stud at end of wire.
2. Open end of wire and install Norseman or Sta-Lok
®
stud after foil is assembled.
3. Rod adapter nosepiece for Harken rod adapter stud: Threaded nosepiece must
have a positive lock as well as adhesive. Use Harken stud with cotter pins
(see page 19).
Crosspin
Fork Attachment
Crosspin
Tang Attachment
Options for Snaking Stay into Foils
WARNING! Using a threaded nosepiece with only adhesive at the
upper rod eye terminal may result in headstay system failure.
Make sure there is a mechanical lock.
MKIV Unit 0 7
Page 8
Preassembly Top Foil Length
Measure A and add to this chart
and length chart below
Inchesmm
A
B.410
E24.0610
F16.25413
G
Total A+B+E+F+G
Make sure upper
measurement points
of A and pin-to-pin
Alternate
Measurement
Point
A
are the same.
TOP FOIL LENGTH WORKSHEET
1
2
3
4
To find “D” pick number from chart below that is closest to,
but not greater than total from step 3.
500 inches “D” = 420 inches 12,000 mm “D” = 10668 mm
5
Result (Pin-to-Pin – ABEFG)
Inchesmm
3 X 84 = 252
4 X 84 = 336
5 x 84 = 420
6 x 84 = 504
Example–If result from Step 3 is:
Result (C) Top Foil Length
Pin-to-Pin Length
Subtract ABEFG
Subtract D
3 x 2133.6 = 6400.8
4 x 2133.6 = 8534.4
5 x 2133.6 = 10668
6 x 2133.6 = 12801.6
–
–
Pin
to
Pin
A
B
C
D
Length Check
After completing worksheet above fill in A, C, D, and G below. Add
“A” through “G” to confirm total equals your pin-to-pin measurement.
Length Chart
DimensionsInchesmm
A Center of Pin to Bottom of Terminal
B Bottom of Terminal to Top of Foil
C Top Foil Length
D Number of Foils ________ x 84" (2133.6 mm)
E Bottom Foil24.00610
F Bottom of Foil to Crosspin16.25413
G Crosspin to Clevis Pin
.4
Pin-to-Pin Length
10
Pin
to
Pin
E
F
G Toggle Distance from Lower Clevis Pin to Crosspin Hole
Toggle Part No.TypeClevis PinG Distance
5
7410.20 5/16Eye/Jaw
7410.20 3/8Eye/Jaw
7410.20 7/16Eye/Jaw
8 MKIV Unit 0
/16"7.9 mm1.1"27 mm
3
/8"9.5 mm1.3"33 mm
7
/16"11.1 mm1.4"36 mm
G
Page 9
Preassembly Short Top Foil
If top foil is shorter than 7" (177.8 mm), use one of the following special techniques to ensure sufficient bearing
surface for the foil in the area of the halyard swivel.
/8" (162 mm)
3
6
63/8" (162 mm) No special treatment required.
/8" (159–117 mm)
5
Cut-Offs
/4"–4
1
6
Do Not Use
61/4"–45/8" (159–117 mm) Do not use plastic bushing
above top connector.
/2"(63 mm)
/2" (38 mm)
1
2" (51 mm)
2
1
1
/2" (13 mm)
1" (25 mm)
1
Cut-Offs
Do Not Use
21/2"–1/2" (63–13 mm) Shorten top foil and adjoining
full length foil so two screws are used to assemble joint
instead of four. Do not use plastic bushings above top
connector.
Top Foil
Length from
Worksheet
1
2
/2"
(63 mm)
2"
(51 mm)
1
/2"
1
38 mm)
1"
(25 mm)
1
/2"
13 mm)
1. Initial
top foil
cut length
55/8"
(143 mm)
5
(130 mm)
45/8"
(117 mm)
4
(105 mm)
35/8"
(92 mm)
1
/8"
1
/8"
2. Cut through
middle hole in
top foil.*
Resulting Top
Foil LengthLength
41/16"
(103 mm)
39/16"
(90 mm)
31/16"
(78 mm)
29/16"
(65 mm)
21/16"
(52 mm)
3. Shorten
full length
adjoining
foil by
cutting
through
middle
hole.*
4. Shorten
connector
(83 mm)
(83 mm)
(83 mm)
(76 mm)
(70 mm)
31/4"
31/4"
31/4"
3"
23/4"
5. Shorten
trim cap
No
No
No
Yes
Yes
/2" (114–89 mm)
1
Cut-Offs
/2"–3
1
4
Do Not Use
Cut-Off
Do Not Use
41/2"–31/2" (114–89 mm) Do not use plastic bushing
above top connector. Shorten top of connector and if
necessary shorten trim cap.
*To allow for saw cut, position blade so upper half of
middle hole is preserved.
/8" (86–67 mm)
5
/8"–2
3
3
Cut-Offs – Do Not Use
33/8"–25/8" (86–67 mm Do not use plastic bushing above
top connector. Cut connector right at cross formed by
glue dispersion channels. Use single foil screw in top
/2" (13 mm)
1
Under
Under 1/2" (13 mm) Eliminate top foil and run foil higher
in drum assembly.
foil only.
MKIV Unit 0 9
Page 10
Preassembly Confirm Foil Length
Confirm foil length by laying foils alongside
stay with turnbuckle components.
Pull stay out so it is straight. Attach Harken
toggle to bottom of stay. Make sure toggle
straps are straight. Adjust turnbuckle so
that length of stay with Harken toggle will
fit boat. Ideally turnbuckle will be half to
two-thirds open to allow for rig adjustment.
Line up drum assembly so holes below
drum line up with holes in Harken toggle.
Make sure toggle is tensioned when
measuring.
Line up bottom foil so foil clamp is just
above or below center of notches in
bottom foil.
Note: Position top foil so that with top
cap the foil will ride 1/2" (13 mm) below
terminal. If wire fitting at top of stay is
swage, foil must ride just below shoulder
of swage. Mark cut line on foil. Wrap tape
around foil as a guide so cut is straight.
If 7301 Halyard Deflector is used, add 1" (25 mm)
10 MKIV Unit 0 4/05/07
Page 11
Assembly Top Foil
Cut foil to length using a hacksaw.
Deburr inside edge using a rat-tail file.
Prepare top foil for drilling.
Tip: Mark top foil to distinguish
from cutoff piece.
Scribe line on top of foil to mark drill
holes. Lay top foil alongside cut-off
piece and use a flat metal object
(i.e. metal ruler) to scribe top
line of foil.
MKIV Unit 0 11
Page 12
Assembly Top Foil
Cut out template at right. Line template up
with top of foil and scribed line. Tape in
place. Use a center punch to mark holes.
Check center punch marks to confirm
3
they are
(20 mm) from top of foil.
Drill two (2) 1/8" (3.2 mm) holes for
trim cap.
/16" (5 mm) and .8" or 13/16"
!
Foil
3
/16" (5mm)
Top
.8" or 13/16"
(20mm)
Lay top foil in line with others. Slide stay
into top foil and down the line of foils or
slide each foil up stay.
12 MKIV Unit 0
Page 13
Assembly Top Foil
Install trim cap. Place each side over wire.
Halyard Deflector
Red Loctite
Push trim cap into foil to start then tap
in using hammer.
Install trim cap screws.
Place halves of plastic bushings on stay
so hooked part of longer section faces out.
Tip: With foil screw holes up as shown
below, place longer half of isolator
with hook on upper half.
®
MKIV Unit 0 13
Page 14
Assembly Top Foil/Connectors
Slip 6.5" (165 mm) connector on wire,
mating hook of plastic bushing with
connector.
Put a drop of red Loctite® into screw holes.
Adhesive inlower half
14 MKIV Unit 0
Page 15
Assembly Foils/Connectors
Hold plastic wedge in place with thumb
as you insert into foil. Line foil holes with
connector screw holes.
Loading Injector with Adhesive
Tip: In cooler weather, keep sealed
adhesive in pocket to keep warm. Use
instructions below to fill injector less
than half way; you will only use a small
amount of adhesive. Refill if needed
but do not keep open sealant for long
periods. Use adhesive within 3 hours.
Use cap of adhesive to break seal. Remove
injector tip cap and plunger. Hold injector
at an angle with applicator tip facing down.
Squeeze adhesive into tube so lower half
of injector is full as shown. Keep tip free
of sealant to let air inside.
Adhesive in
lower half
Start plunger into injector and immediately
hold upright so plunger is down and
applicator tip is up.
As sealant runs down towards plunger an
air pocket will form near tip. Push plunger
to evacuate air. You are now ready to begin
injecting adhesive.
MKIV Unit 0 15
Page 16
Assembly Foils/Connectors
Inject only a small amount. A Unit 0 will
1
only take
/4 to 1/3 of a graduation mark.
Tip: When you see a small amount of
adhesive enter one of the screw holes,
stop—you have applied enough adhesive.
Use “ml”
marks to
1
/4
estimate
1
/3 ml of
to
Stop when you see a small
amount of adhesive enter
one of the sdrew holes.
adhesive
Tighten screws into connector holes. Make
®
sure a drop of red Loctite
entered each
screw hole. If not, apply to screw.
Red Loctite
Use bushings, connector, wedge, and
®
red Loctite
in other screw holes and
insert into other foil. Then inject 1/4–1/3 ml
of adhesive.
16 MKIV Unit 0
®
Page 17
Assembly Bottom Foil/Connectors/Halyard Swivel
Continue installing connectors and wedges.
®
Make sure to use red Loctite
in screw
holes.
Red Loctite
®
Continue assembly. Use 10" (254 mm)
bottom connector to assemble bottom foil.
Slide halyard swivel onto foil above feeder
window. Make sure taller “half” is up as
shown.
MKIV Unit 0 17
Page 18
Assembly Drum Assembly
Loosen foil clamp screws at top of
lower unit.
Slide drum assembly onto foils.
Tip: Face clamp downward so it clears
foil notches when installing.
18 MKIV Unit 0
Page 19
Assembly Rod Adapter Stud
Apply a few drops of red
Loctite
Screw main threaded stud
portion onto bronze nosepiece
until flats align with two cotter
pin holes in terminal body.
Tip: Turn nosepiece completely
into threaded stud portion.
Flats will be close and may
only require a small half turn
to align with cotter pin holes.
®
to threads of nosepiece.
Insert two cotter pins and
®
spread. Clean excess Loctite
from terminal body using
special care to ensure that
there is no red Loctite
threaded stud.
®
on
ROD RIGGING
MKIV Unit 0 19
Page 20
Assembly Attach Turnbuckle/Toggle
Assemble turnbuckle and attach Harken
toggle.
®
Note: If using Sta-Lok
or Norseman®
stud, you must use a washer above
stud as shown below.
Washer
Turnbuckle
Clevis Pin
Eye/Jaw Toggle Assembly
Crosspin
Toggle
Clevis Pin
20 MKIV Unit 0
Page 21
Assembly Final
If stay length is set, use side cutters or
needle nose pliers to bend cotter pin to
secure turnbuckle.
Slide lower unit down over turnbuckle
and attach using long crosspin.
Use plastic bushings provided.
WARNING! Crosspin must be at
90 degrees to clevis pin that
attaches unit to boat. If pins run
same direction toggle will fatigue
and could break suddenly.
Check foil height at top, set and secure
using hex key.
See tip on next page.
Clevis Pin
Crosspin at 90°
to Clevis Pin
MKIV Unit 0 21
Page 22
Assembly Feeder/Final
Tip: Do not remove foil clamp screws
to adjust foil. Loosen screws, hold foils,
and bring clamp away from foils. Adjust
and reclamp.
Slide halyard swivel above feeder. Place
feeder in foil recess. Push screw down so
tab catches under foil. Tighten screw.
Note: Screw will turn with some difficulty.
It is plastic coated to prevent loosening
due to vibration.
IMPORTANT! When removing screw,
loosen no more than one full turn.
Slide screw up and remove feeder.
22 MKIV Unit 0
Page 23
Commissioning Turnbuckle on Boat
Have extra cotter pins on hand to replace used ones at base of
unit and for turnbuckle.
Hold foils and loosen drum assembly screws until you can pull
clamp out to lower foils.
Lower foils.
Remove crosspin holding drum assembly to turnbuckle.
Raise drum assembly and use halyard to lift and hold it about
5' (1.5 m). Raise foils using second halyard and secure. Allow
room above for turnbuckle take up.
CAUTION! Make sure drum assembly and foils are
securely lifted using a halyard before adjusting turnbuckle. Foils can drop suddenly causing injury to hands.
Adjust turnbuckle.
Replace used cotter pins. Lower drum assembly and install clevis
pin and new cotter pin.
3
Lift foils so top is
/8" (10 mm) below upper terminal.
WARNING! Stay must attach to toggle using clevis
pin. Do not attach stay to crosspin at drum assembly
because crosspin will fatigue and break.
Stay
Clevis
Pin
Crosspin
Hole
Crosspin
Crosspin
Hole
MKIV Unit 0 23
Page 24
Commissioning Leading Line to Cockpit
Run line through enclosed window in guard and into hole
in bottom plate of spool. Tie a small overhand knot and
pull it up under drum assembly.
WARNING! Lead line through enclosed window. If
line is led through opening between two enclosed
windows it can ride above lineguard and jam
furler which can cause loss of control of boat.
Enclosed Window
Note location of sun cover. Charge system by rotating furler to wrap line on drum.
Tip: Sun cover to starboard—turn clockwise to charge. Sun cover to port—turn counter-clockwise.
Tension line while charging.
Mount Lead Blocks
Furling line can be led down either side of boat. If boat is in slip, consider mounting opposite dock.
Remove four screws on stanchion blocks. Clamp blocks to stanchions. See instructions below.
Tip: Start all four screws before tightening.
BOW
7401
FORWARD
STANCHION
BLOCK
OUTBOARD
STANCHION
7403
BLOCK
OUTBOARD
STANCHION
OUTBOARD
STANCHION
7403
BLOCK
7403
BLOCK
7401 Forward Stanchion Block
Position 7401 Forward Stanchion Block so line enters
drum at right angles to headstay and centers vertically
in opening. Install so line is inside stanchion.
Correct block position is critical to even line
spooling and ease of furling.
7403 Outboard Stanchion Blocks
Install 7403 Outboard Stanchion Blocks so line is
outside stanchions.
Number and placement of leads depends on boat
length and number/configuration of stanchions.
7402 Ratchet Stanchion Block
Mount 7402 Ratchet Stanchion Block as furthest-aft
lead to prevent line overrides in drum when unfurling.
Position ratchet block so line turns at least 90°.
Install so line is inside stanchion.
Lead line through block so ratchet makes
clicking sound when pulling line to furl sail.
Tip: Make sure ratchet switch is in “ON” position. If there is
no clicking sound, lead line through block in opposite direction.
Lead line to Furling Line Cleat in cockpit.
HCP168 Furling Line Cleat
Install so line is angled as shown.
7402
RATCHET
STANCHION
BLOCK
Use #10 (5 mm) fasteners.
Note: As furling line lead changes, make sure line
doesn’t chafe against line guard. Rotate line guard
STERN
24 MKIV Unit 0
if necessary.
Drum Full
(sail unfurled)
Drum Empty
(sail furled)
Page 25
Commissioning Halyard Wrap/Prevent Halyard Wrap
Halyard Wrap
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.
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 will unfurl, 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.
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 may cause these parts to
break suddenly causing mast to fall down while person is aloft. Sailing or motoring with boat after a wrap
can result in the headstay breaking and mast falling down. Before using boat, have a professional rigger
inspect and replace parts as necessary using following methods.
A professional rigger must carefully inspect the masthead area using a secure hoisting method. Inform rigger that
there has been a halyard wrap so they 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.
Prevent Halyard Wrap
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
8–10°
to prevent halyard wraps and possible headstay loss.
1. Halyard swivel should be within top 4–6" (100–152 mm) 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, but 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.
If the your sail luff is not long enough to position halyard swivel high
enough to create an 8–10° angle as shown, you must add a pendant.
Pendants should be made of plastic-coated wire and be permanently
attached so sail height will be correct. Adjustable- length pendants
are not acceptable, as they might not be adjusted
correctly during a sail change.
1. Raise sail, but do not attach tack shackle.
2. Position halyard swivel correctly near top of headstay.
3. Secure halyard.
4. Tie a piece of rope to sail tack.
5. Lead line through tack shackle on furling drum.
6. Tension sail.
7. Measure distance from tack shackle to sail tack and permanently
attach pendant of this length to head of sail.
8. Repeat procedure for every jib in your sail inventory.
Halyard Deflector/Halyard Restrainer
To prevent wraps, jib halyard must pull slightly to rear. On most boats,
halyard lead angle is acceptable if halyard swivel is raised to top of foil.
On some boats halyard sheaves are located too close to headstay and
a Halyard Deflector or Halyard Restrainer must be used.
Halyard restrainers should be used only when required by masthead
geometry. Restrainers tend to limit sail luff length and may cause
problems if not installed properly.
If your boat needs a Halyard Deflector, use Part No. 7301 or a Halyard
Restrainer, use Harken Part No. 944.
Restrainer should be mounted as high as possible on face of mast.
Position restrainer so that foils will not hit it when under load.
The restrainer should deflect halyard as little as possible or you may
experience difficulty in tensioning sail luff, friction when furling, and
possible damage to foils. To decrease deflection angles, shorten sail luff.
Tip: Boats used in charter service should have a halyard restrainer,
regardless of masthead geometry.
Halyard Tension
The jib halyard should be firm, but not too tight.
Tip: The luff foil system supports sail along its length so halyard
tension is used only to shape sails, not to support them. Use enough
halyard tension to remove some wrinkles along luff of sail. Do not
tension halyard enough to cause vertical wrinkles in luff of sail.
Tension to adjust position of draft in sail to suit sailing conditions.
Halyard should be firm but not tight. If in doubt, release halyard
tension. To protect sail, ease halyard when boat is not in use.
Spinnaker halyards occasionally cause problems
with furling.
WARNING! In severe cases, spinnaker
halyards can jam furler causing loss of
control of boat. Make sure halyards are
clear of top of foils and halyard swivel.
On many boats it will not be possible to attach
spinnaker halyard to bow pulpit or it may be
"sucked" into jib when furling.
On some boats the spinnaker halyard lays across
headstay and will catch on halyard swivel, foils or
jib halyard. To prevent problems it may be necessary
to install a masthead bail to move spinnaker halyard
block forward and to one side.
Boats with external halyards may find it necessary to
flip both ends of spinnaker halyard behind spreaders
to prevent fouling with furling system.
Headstay Tension
A furling system will work best if headstay is tight.
A loose headstay is difficult to rotate and can cause
unusual wear on foil joints.
To adjust headstay tension, remove sail and furling line
from unit and follow instructions on page 23.
Tip: Before adjusting headstay tension, slack
mainsheet and vang.
Backstay Adjuster
Backstay adjusters allow headstay tension to be varied to change sail shape to
match conditions. They permit a very tight headstay to be eased when boat is not
in use. For best performance, consider adding a backstay adjuster; either a block
and tackle, a mechanical adjuster like those offered by Harken, or a hydraulic adjuster.
Remember to keep headstay tight for best performance when furling or reefing.
If your boat is fitted with an adjuster be sure that it is tensioned before the halyard
is tensioned. If not, backstay adjuster may increase halyard tension and could
damage the sail or furling system.
Racing boats often slack the headstay completely when sailing downwind. Check
to be sure that foil does not jam against upper headstay terminal when backstay
is released. To prevent this, it may be necessary to shorten foil slightly.
MKIV Unit 0 27
Page 28
Operation Sail: Raise/Storm/Reef
Raise Sails
1) Install prefeeder by securely tying end of line to a deck fitting or to toggle
below furler so it is 2' (610 mm) below feeder.
2) Shackle tack of sail to drum. Install shackle so screw pin head is on same
side as sun cover.
3) Secure genoa sheets to clew of sail.
4) Attach genoa halyard to halyard swivel.
5) Pass luff tape through prefeeder and feeder into foil groove.
6) Attach head of sail or pendant at head of sail to halyard swivel.
7) Hoist sail.
Tip: New sails are often stiff and may hang up on prefeeder during
raising. Do not force sail when it hangs up—lower and remove
twist. Sails "break in" with use and will become easier to raise.
Storm Sails
Most people will use one multi-purpose genoa for all their sailing, but it is not good seamanship to go offshore
without storm sails.
Heavy-air working jibs and storm sails may be used with your unit. These sails need to have luff tape added to allow
them to be raised in headstay foils.
These sails will generally require pendants to ensure that halyard swivel is properly positioned at top of headstay. See
page 26.
Remember that heavy-air working jibs and storm jibs may be reefed and furled like any other sail.
Furl and Reef
To furl or reef, ease the jib sheets and pull
furling line.
In very light air, it may be necessary to place
some tension on jib sheet to insure a tight furl.
In a breeze, you must completely luff sail by
totally slacking jib sheets before furling.
The furling line should pull readily. The amount
of force required is related to amount of wind,
but Unit should never require use of a winch to
furl. If the sail will not furl, or if furling requires a
great deal of effort, there is a problem with system. Consult the Troubleshooting
Guide on Page 32. Do not use a winch to force a system to turn. If you are certain
that the system is operating properly, you may use a winch to make furling easier.
28 MKIV Unit 0
Page 29
Operation Reef/Secure Sail
Reef
A sail may be partially furled before you resume
sailing. This is known as reefing.
Many sailors find it helpful to place marks on
foot of sail so that they can reef to a variety of
predetermined jib sizes. This allows marks to be
placed on jib lead tracks or toe rail so that lead
block position can be changed to correspond
to reefed jib.
Sails are generally reefed to balance boat and to
reduce heeling moment. Sails may also be reefed
to improve visibility or to slow boat while sailing in
congested areas or entering or leaving harbors.
Secure Sail
When furling the sail completely, make sure sheets and furling line are
secured. Check amount of line on the spool compared to the furled sail
before using the system.
A furled sail must have:
a. Two to three wraps of jib sheet wrapped around sail.
b. Two wraps minimum of line wound on spool.
c. Furling line securely cleated.
d. Jib sheets securely wrapped on winch and held in self-tailing jaws.
Furl at dock with tension on sheets to duplicate furling in high wind.
Remember sails furled in light wind and left loosely secured can be a problem
if wind increases.
IMPORTANT! Remove sail from furler if extreme winds are predicted,
especially if boat is left unattended.
IMPORTANT! Check all points above—a, b, c, and d—when leaving boat to
avoid damage to furler or boat.
A loosely rolled sail can catch wind in a storm. Sheets or furling lines can
loosen as winds increase and allow furler to unroll. If no wraps of line are on
spool, the line deadend can break the drum when the boat motors through
waves.
Be sure mooring lines are not placed across furling line where they may
cause chafe.
a. 2–3 wraps
b. 2–3 wraps
If you want to:
Add more wraps of
jibsheet on furled sail.
Add more wraps of line
on spool.
MKIV Unit 0 29
Untie jib sheets and keep sail
completely rolled. Secure with
sail tie.
Turn spool to unroll a
couple of wraps of line.
Turn spool to add a
couple of wraps of line.
Retie sheets.
Page 30
Operation Race Conversion
1.
2.
1. Loosen screw
one revolution only.
2. Slide screw up.
Remove feeder.
3. Lower halyard
swivel.
To Remove
Feeder For
Racing
Race conversion allows use of both grooves
for sail changes and tacking genoas on deck
for use of maximum luff length genoas.
Halyard Swivel Below Feeder
Use halyard to lift halyard swivel up, away
from feeder. Loosen screw one revolution only. Slide screw up and hold. Remove
feeder carefully—bottom end first. Don’t lose the feeder overboard! Lower swivel
onto torque tube. Replace feeder.
Halyard Swivel Off Furler
Serious racers may want to remove the
halyard swivel.
Note: It is not possible to remove halyard
swivel on a unit with a Norseman/Sta-Lok
or rod adapter stud unless you disassemble
terminal stud. Make sure you use a new
Norseman/Sta-Lok wedge to reassemble
Norseman/Sta-Lok fitting.
Remove Feeder
Loosen screw one revolution only.Slide screw up and hold.
1) Remove drum assembly.
2) Rig a secure, temporary headstay.
3) Loosen backstay, mainsheet, and vang
so that headstay goes slack.
4) Remove clevis pin holding furling unit
to chainplate.
5) See adjusting turnbuckle on Page 23.
Remove turnbuckle body and lower
unit and slide off halyard swivel.
6) Reattach headstay to boat.
Removing Drum
1) Remove sail and unwind the line from
drum. Line can remain attached to drum.
2) Use 5 mm hex key provided to remove
2 screws on bottom of guard assembly
and remove two halves. Be careful—
screws are not captive.
3) Use a 2.5 mm hex key to loosen four
screws in plastic cover and flange.
30 MKIV Unit 0
Carefully remove feeder–bottom end first.
Don't drop the feeder overboard!
Page 31
Maintenance Clean/Inspect/Remove Furler
Clean and Lubricate
Keep unit clean. When you wash boat, flush unit with
soap and fresh water. Occasionally lower sail and flush
halyard swivel with soap and fresh water.
At least twice a year unit should be cleaned more
thoroughly by removing line (first note direction of
spool) and flushing bearings with soap and fresh water.
After unit has dried, apply a dry spray lubricant such as
®
McLube
.
Foils may be cleaned by washing with soap and water.
A scrap of luff tape may be run up foil to scrub inside
grooves.If lubrication is required, spray a thin coat of
®
McLube
SailKote on sail luff tapes away from boat deck.
WARNING! Periodically inspect items listed
below and any others as necessary. Failure
will cause slippery decks which may result in
loss of footing, falling overboard.
to inspect can cause an accident.
Inspect
Inspect unit for signs of chafe, wear, or damage.
Inspect clevis and cotter pins below and inside drum assembly for
signs of loosening. Check headstay tension for signs of loosening.
Inspect swage fitting and lower toggle for signs of stress
corrosion.
Inspect Norseman or Sta-Lok terminal or rod terminal for
signs of loosening.
Inspect all screws on unit to be sure they have not loosened.
Inspect foil to make sure that it has not dropped into drum
assembly. Periodically inspect wire for signs of wear or unraveling.
Replace Line
Use Harken HFG594 furling line or source a good-quality, double-braid polyester line with good wear characteristics.
WARNING! Do not spray foil on boat. McLube®
9
/32" (7 mm) line with break strength exceeding 2500 lbs (1130 kg). Smaller boats or smaller sails may allow
Use
5
/16" (8 mm) line. If a larger-diameter line is desired, consult with a rigger about using tapered line with a high
strength core and cover removed in forward part of line.
Storage – Mast Down
In areas where it freezes, do not store system where water can accumulate in foils. When water freezes it will rupture
aluminum. Store foils under cover, with grooves facing down or on an angle so water will run out.
Storage/Transporting
Do not store or transport system with drum assembly extending beyond mast. Remove masthead clevis pin and shift
furler up so drum assembly can be strapped securely to mast. Some people remove drum assembly and halyard swivel
for storage and transport.
After Storage or Transport
After storing or transporting unit, clean thoroughly including ball bearings. See instructions above.
Loosen Foil Clamp Before Slacking Backstay
In order to prevent foils from locking against upper stay terminal when backstay is released, loosen foil clamp screws and
lower foil before loosening backstay.
MKIV Unit 0 31
Page 32
Troubleshoot
ProblemProbable CauseSolution
Sail will not furl or
is difficult to furl.
Sail will not unfurl
or will not unfurl
completely.
Sail will not furl
completely.
Headstay rotates in
jerks or elliptically.
Sail does not stay
furled.
Sail will not go up.
Sail will not raise
completely or luff
will not tension.
Sail will not
come down.
Ultravoilet cover rolls
up inside of sail.
Line jams betweenguard
and plastic spool plate.
Delrin® is a registered trademark of E. I. du Pont de Nemours and Company or its affiliates.
Igus® is a legally registered trademark of Igus® GmbH and/or Igus® Inc.
Loctite® is a trademark of Henkel AG & Company KGaA
Jib halyard is wrapping around headstay because
angle between mast and and halyard is too shallow
Jib halyard is wrapping around the headstay
because halyard swivel is too low.
Jib halyard is too tight.Ease jib halyard.
Foils riding on turnbuckle.Raise foils. See adjusting turnbuckle on page 23.
Foils too high, binding on swage eye.Lower foils until clear. See adjusting turnbuckle on page 23.
Spare halyard is wrapping in sail as it furls.Secure spare halyards away from furling headstay by flipping them behind spreaders
Salt or dirt in bearings.Flush bearings frequently with fresh water and a detergent solution.
Furling line tangled in drum.Overrides are best prevented by using a 7402 ratchet block as the last furling line lead to
Stop knot catching.Make sure knot is a single overhand and is pushed up inside drum.
Sail full of wind.Luff completely before furling or reefing.
Sail flogging too much.Release a short length of sheet, pull some furling line and repeat.
Jib sheets are not free.Free jib sheets.
Foil out of drum assembly.Reinstall foil in drum assembly and tighten clamp screws.
No wraps of furling line on drum.Remove sheets. Rotate stay wrapping as much furling line on drum as possible.
Lineguard assembly has slipped down.Tighten line guard assembly screws securely.
Jib halyard is wrapping around headstay because
angle between mast and halyard is too shallow.
Jib halyard is wrapping around the headstay
because the halyard swivel is too low.
Foils riding on turnbuckle.Raise foils. See adjusting turnbuckle on page 23.
Foils too high, binding on swage eye.Lower foils. See adjusting turnbuckle on page 23.
Jib halyard is too tight.Ease jib halyard.
Spare halyard is wrapping in sail as it furls.Secure spare halyards away from furling headstay by flipping them behind spreaders
Salt or dirt in bearings.Flush bearings with freshwater and lubricate with dry spray lubricant such as McLube
Furling line is not free.Free furling line.
Insufficient furling line on drum.Remove sheets. Rotate stay, wrapping as much furling line on drum as possible.
Too much line on drum.Adjust amount of line on drum or change position of forward lead block to allow line
Spare halyard catching in sail as it furls.Move halyards away from furling headsail as above.
Insufficient tension on headstay.Tighten headstay and/or backstay to eliminate sag in headstay.
Sail not furled tightly on stay.Maintain drag on sheets while furling.
Furling line not secure.Secure furling line.
Luff tape will not go into groove.Check luff tape for fraying.
Sail catching at prefeeder.Flake sail more loosely on deck.
Dirt in groove.Clean groove.
Halyard swivel is hitting end stop.Luff of sail is too long and must be recut.
Angle between halyard and mast is too sharp
and halyard is pulling too much to the rear.
Halyard is wrapping on headstay.Angle between headstay and halyard is too shallow and must be optimized per installation
Halyard swivel off foil.Sail luff too long or foil is too short or low and must be lengthened or raised.
Furling line is wrapped on drum in wrong direction.Remove sheets. Pull line to remove all furling line from drum. Turn stay to rewind line on
Line is not led through windows.Pull line through enclosed window.
See installation instructions regarding optimal halyard angle. It may be necessary
to mount a halyard restrainer on front of your mast to hold halyard to rear.
See installation instructions regarding optimal halyard swivel height. A wire pendant
may be needed at head of sail to raise halyard swivel to proper height.
maintain proper drag on line while unfurling.
See installation instructions regarding optimal halyard angle. It may be necessary to
mount a halyard restrainer on front of your mast to hold halyard to rear.
See installation instructions regarding optimal halyard angle.
to roll evenly on drum.
Check luff tape size.
Halyard must be routed from a point higher on mast. This may require that any halyard
turning blocks aloft be replaced or sail shortened.
instructions.
drum in opposite direction. Line guard and cowling alignment may need to be adjusted.
McLube™ is a registered trademark of McGee Industries, Inc.
®
is a registered trademark of Sta-Lok Terminals, Ltd.
Sta-Lok
®
Torlon
is a registered trademark of Solvay Advanced Polymers
Clean/Inspect 32
Replace Line 32
Storage 32
Remove Furler 32
Troubleshoot 30
Warranty 30
Appendix
Please read these instructions carefully before installing, servicing, or operating the equipment.
This manual may be modified without notice. See: www.harken.com/manuals for updated versions.
4416
HFG739
HFG722
947
8
7404
2110
9
944
HFG200/HFG201
7301
HFG594
HCP1387
HCP1089
HFG642
34 MKIV Unit 0
DescriptionOrderPart No.
Instruction Manual14416
8
Prefeeder1947
Red Loctite
®
2HFG739
5200 Adhesive Set1HFG725
5200 Marine Adhesive Sealant1HFG722
Injector1
7 mm Single Braid Polyester (55' / 16.7 m)1HFG594
DescriptionOrderPart No.
Lead Block Kit17404
9
29 mm Outboard Lead Assembly37403
57 mm Carbo Ratchet Assembly17402
40 mm Carbo Assembly17401
Horn Cleat1HCP168
Bow Shackle (6 mm)32110
Halyard Restrainer1944
Sheave/SS Inner Race Only1944ASSY
Clevis Pin (1/4" x .9" 18-8)1HFG467
Bracket-Small1HCP393
Cotter Pin (1/16" x 1/2" 18-8)1HFS118