Harken MKIV OCEAN Unit 3 User manual

Please read these instructions carefully before installing, servicing, or operating the equipment.
This manual may be modified without notice. See: www.harken.com/en/support/manuals/ for updated versions.
PLEASE SAVE THESE INSTRUCTIONS
MKIV OCEAN - JIB REEFING & FURLING
Unit 3
Installation Manual – Intended for specialized personnel or expert users
5392 03/21
Preassembly
Safety Precautions/Parts Descriptions 2
Sizing Check 3
Parts 4
Rigging Parts Check/Tools 5
Dimensions/Sailmaker's Instructions 6
Toggle Deductions/Stay Into Foil Options 7
Top Foil Length 8
Short Top Foil 9
Confirm Foil Length 10
Assembly
Foils/Connectors 11–14
Halyard Swivel and Drum Assembly 15
Rod Rigging 16
Turnbuckle/Toggle 17–19
Final/Feeder 20
Commissioning
Turnbuckle 21
Lead Line to Cockpit 22
Halyard Wrap/Prevent Halyard Wrap 23
Pendant/Halyard Restrainer/ Halyard Tension 24
Operation
Spinnaker Halyards/Headstay and Backstay Tension 25
Raise Sails 26
Furl/Reef 26–27
Secure Sail 27
Maintenance
Clean/Inspect 28
Replace Line 28
Storage/Remove Furler 28
Troubleshooting/Warranty 29
Parts Lists 30-31
Contact Harken 32

2 MKIV Ocean Unit 3
Safety Precautions/Parts Description
4
1
2
3
7
6
8
9
5
1) Toggle Assembly
2) Short Link Plates
3) Shackles
4) Drum Assembly
5) Foil Clamp Screws
6) 2' (610 mm) Bottom Foil
7) Feeder Assembly
8) Connector Bushing
9) Bottom Connector
10) 7' (2.13 m) Foil
11) Connector Screws
12) Connector
13) Halyard Swivel
14) Trim Cap
15) Trim Cap Screws
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/en/general-warnings-instructions/
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/en/general-warnings-instructions/ for general
warnings and instructions.

MKIV Ocean Unit 3 3
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. To clear
anchor use a Harken Long Link Plate which can be cut to various lengths.
Sizing Check
Unit Part No. Description Wire Sizes
7513.10 MKIV OCEAN Unit 3
7
/ 16 ",
1
/ 2 ",
9
/ 16 ",
5
/ 8 "11 mm, 12 mm, 14 mm, 16 mm
Rod Sizes
-22, -30, -40, -48 9.53 mm, 11.1 mm, 12.7 mm, 14.3 mm
Toggle Part No. Description Chainplate Clevis Pin Size
7413.20 3/4 Jaw/jaw toggle w/short link plate
3
/ 4 "19.1 mm
7413.20 7/8 Jaw/jaw toggle w/short link plate
7
/ 8 "22.2 mm
7513.20 1 Jaw/jaw toggle w/short link plate 1" 25.4 mm
7513.20 1 1/8 Jaw/jaw toggle w/short link plate 1
1
/ 8 "28.6 mm
7313.21 3/4 Long link plate w/jaw/jaw toggle
3
/ 4 "19.1 mm
7313.21 7/8 Long link plate w/jaw/jaw toggle
7
/ 8 "22.2 mm
7513.21 1 Long link plate w/jaw/jaw toggle 1" 25.4 mm
7513.21 1 1/8 Long link plate w/jaw/jaw toggle 1
1
/ 8 "28.6 mm
Chainplate Clevis Pin
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.
Preassembly Sizing Check
10
11 8
12
13
14
15

4 MKIV Ocean Unit 3
Preassembly Parts
Part No. Quantity Description
HFG996 1 Drum assembly with shackle
HFG997 1 Halyard swivel with shackles
Main Components
7513.30 1 Extra 7' (2.13 m) Foil
7513.31 1 Extra Connector with Bushings and Screws
Ordered Separately (For longer headstays)
Hex Keys
Connectors
Trim Cap
Trim Cap Screws
Feeder and Screws
Red Loctite®
Connector Bushings
Halyard Swivel
Foil Screws
Drum Assembly
7513.FOILSET 1 Foils (Standard package)
Includes 10 7513.30 Foils 7' (2.13 m)
17513.33F 2' (610 mm) Bottom
Part No. Quantity Description
7513.31F 10 7" (177.8 mm) Connectors
HFG1017 1 Connector bushing set
Includes 10 H-84186 Bushing connector half - top
10 H-84187 Bushing connector half - bottom
HFG1011 1 Foil screw set
Includes 44 HFS1060 Foil screws (extras included)
HFG1012 1 Trim cap set
Includes
1H-84231 Trim cap half - top
1H-84232 Trim cap half - bottom
3HFS1127 Trim cap screws (includes one extra)
HFG1013 1 Feeder set
Includes 2H-84247 Feeder half
5HFS119 Feeder screws (includes one extra)
Loctite is a trademark of Henkel AG & Company KGaA
Part No. Quantity Description
Various 4 Hex keys - M3, M4, M5, M6, M10
HFG739 1 Red Loctite®(for foil screws)
833 1 Blue Loctite®(for feeder screws)
Supplied Tools and Adhesives
Foil Assembly Components
7' (2.13 m)
Foils
Blue Loctite®
2' (610 mm)
Bottom Foil

MKIV Ocean Unit 3 5
Preassembly Rigging Parts Check/Tools
Tools You Will Need
1. Long tape measure 6. Side cutters 11. Rigging or black tape
2. Short tape measure 7. Rat-tail file 12. Center Punch
3. Power drill 8. Hex keys (provided) 13. Hammer
4. Drill bit – 1/8" (3 mm) 9. Slotted/phillips screwdrivers
5. Hacksaw 10. Needle-nose pliers
10
11
12
8
7
6
5
3
2
1
13
4
9
All Units.
Harken toggle
(sold separately).
1. Harken toggle assembly required. Sold separately.
2. Mating turnbuckle components, with eye at lower
end, must be purchased separately.
3. Headstay might require cutting and shortening to fit
Harken toggle. .
4. Rod rigging requires Harken rod adapter stud.
Toggles
Furling line is not included with furling unit. Purchase 12 mm (7/16") low - stretch
polyester double - braid line. Line length should be equal to the length of the
boat, plus the length of the foot of the largest genoa, plus 2 m (6').
Line Diameter/Length
WARNING! A stay that is old or damaged can
break suddenly, causing an accident. Headstay
condition should be checked by a professional
rigger before reusing.
Unit Part No.
3
7313.21 3/4
7313.21 7/8
7513.21 1
7513.21 1 1/8
Long link
plate w/toggle
Rod Rigging.
Harken rod adapter
stud required
(sold separately).
Unit Part No. UNF
thread
3
7426 -22 3/4"
7427 -30 7/8"
7428 -40 1"
7429 -48 1 1/8"
Rod adapter stud
Unit Part No.
3
7413.20 3/4
7413.20 7/8
7513.20 1
7513.20 1 1/8
Jaw/jaw toggle w/
short link plate
Line not included

6 MKIV Ocean Unit 3
Feeder height
Max 49 5/16" (1252 mm)
Min 45 1/2" (1156 mm)
Tack setback
1 15/16" (49 mm)
9 3/4 "
(247 mm)
3 1/8"
(79 mm)
7 3/8"
(188 mm)
Max 18 3/8" (467 mm)
Min 16 9/16" (421 mm)
Max 16 5/8" (420 mm)
Min 14 7/16" (373 mm)
Luff Tape Length
Note feeder height and extend bottom of luff tape downward so it is below
feeder. This will prevent luff tape from catching in feeder as
sail is lowered.
Tack and Head Shackles
Make sure tack and head shackles fit sail
rings. Minimum inside dimensions of
standard head and tack shackles are:
(A) 2" (50 mm)
(B) 13/16" (21 mm)
Sun cover
Sun covers may be installed on either side of the sail.
Be sure to match other sails in the customer's inventory.
Long link plate note: If a long link plate is used, add the following dimen-
sions to feeder, tack shackle, and drum height. The 3/4" (19.1 mm) and
7/8" (22.2 mm) link plates can shorten to one of five hole positions. The 7 3/4"
(197 mm) is with the link plate shortened all the way.
Do not add to halyard swivel or top terminal dimensions.
3/4" (19.9 mm) Clevis pin Add 16 5/8" to 7 3/4"(422 mm to 197 mm)
7/8" (22.2 mm) Clevis pin Add 16 5/8" to 7 3/4"(422 mm to 197 mm)
Note: These additions are determined by subtracing the short link plate
assemblies from the length of the long link plate assembly.
1" (25.4 mm Clevis pin Add 16 1/2" 420 mm)
1 1/8" (28.6 mm) Clevis pin Add 16 1/2" 420 mm)
A
B
Luff Length
Note offsets above and below sail.
A shorter luff may be required if a halyard restrainer is necessary
(page 24) or a toggle or long toggle assembly is used to raise drum.
If luff of sail is not long enough to put halyard swivel near top of
headstay foil, a pendant must be added (see page 24).
Tack Setback
Note setback for tack shackle and cut the sail accordingly. Min is for eye/jaw
and jaw/jaw toggles. Max is for stud/jaw toggles. See long link plate note.
Luff Tape Size -6 (5 mm or 6/32")
J - Finished luff tape size: 5.5 mm (0.215")
K - Luff rope size: 4.8 mm (6/32", 3/16")
L - Max Ø in sail groove: 6.5 mm (0.26")
M - Gap in sail groove: 2.4 mm (0.096")
J
K
L
M
Preassembly Dimensions/Sailmaker's Instructions
Max 8 15/16"
(227 mm)
Min 7 1/8"
(181 mm)

MKIV Ocean Unit 3 7
Preassembly Toggle Deductions/Stay Into Foil Options
Options for Snaking Stay into Foils
Use dimensions of Harken toggle below to build stay to correct length.
Tip: Turnbuckles should be 1/2 to 2/3rds open to allow shortening for new wire stretch and for
fine-tuning mast rake.
1. Swage stud at end of wire.
2. Open end of wire and install Norseman or Sta-Lok®
stud after foil is assembled.
3. When using smaller wires, marine eye may fit. See page 12.
4. Rod adapter nosepiece for Harken rod adapter stud.
WARNING! Using a threaded nosepiece with only
adhesive at the upper rod eye terminal may result
in headstay system failure which can cause an
accident, damage to your vessel, personal injury,
or death. See www.harken.com for additional
safety information.
STA-LOK is a registered trademark of STA-LOK Terminals Ltd.
Unit Clevis pin Ø Pin-to-pin length
33/4" (19.1 mm) 3 9/32" (83 mm)
7/8" (22.2 mm) 3 7/8" (98 mm)
Unit Clevis pin Ø Pin-to-pin length
3
3/4" (19.1 mm) 3 9/32" (83 mm)
7/8" (22.2 mm) 3 7/8" (98 mm)
1" (25.4 mm) 4 9/16" (115 mm)
1 1/8" (28.57 mm) 5" (127 mm)
Unit Clevis pin Ø Pin-to-pin length
31" (25.4 mm) 4 9/16" (115 mm)
1 1/8" (28.57 mm) 5" (127 mm)

8 MKIV Ocean Unit 3
UNIT 3
Alternate
Measurement
Point
Make sure upper
measurement points
of A and pin-to-pin
are the same.
1Pin-to-Pin Length
2Subtract ABEFG –
3Result (Pin-to-Pin – ABEFG)
4Subtract D –
To find “D” pick number from chart below that is closest to,
but not greater than total from step 3.
Inches mm
7 x 84 = 588
8 x 84 = 672
9 x 84 = 756
10 x 84 = 840
11 x 84 = 924
7 x 2133.6 = 14935.2
8 x 2133.6 = 17068.8
9 x 2133.6 = 19202.4
10 x 2133.6 = 21336
11 x 2133.6 = 23470
Example–If result from Step 3 is:
800 inches “D” = 756 inches; 20,000 mm “D” = 19202 mm
5Result (C) Top Foil Length
Pin-to-Pin Length Worksheet
Dimensions Inches mm
ACenter of Pin to Bottom of Terminal
BBottom of Terminal to Top of Foil
.5 13
CTop Foil Length
DNumber of Foils ________ x 84" (2133.6 mm)
EBottom Foil 24.0 610
FBottom of Foil to Crosspin 30.8 782
GCrosspin to Clevis Pin
Pin-to-Pin Length
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 Check
G Toggle Distance from Lower Clevis Pin to Crosspin Hole
Toggle Part No. Type Clevis Pin G Distance
7413.20 3/4 Jaw/jaw with short link plate
3
/ 4 " 19.1 mm 5.42" 138 mm
7313.20 7/8 Jaw/jaw with short link plate
7
/ 8 " 22.2 mm 6.00" 152 mm
7513.20 1 Jaw/jaw with short link plate 1" 25.4 mm 6.79" 173 mm
7513.20 1 1/8 Jaw/jaw with short link plate 1 1/8" 28.6 mm 7.24" 184 mm
7313.21 3/4 Long link plate w/toggle
3
/ 4 " 19.1 mm 22.00" 559 mm
7313.21 7/8 Long link plate w/toggle
7
/ 8 " 22.2 mm 22.63" 575 mm
7513.21 1 Long link plate w/toggle 1" 25.4 mm 23.32" 592 mm
7513.21 1 1/8 Long link plate w/toggle 1 1/8" 28.6 mm 23.64" 604 mm
Note: If long link plates of 7313.21 3/4 or 7313.21 7/8 are shortened, dimension must be
changed or foil will be too short. Measure distance from crosspin down to where clevis pin
attaches toggle to boat and use this dimension in G above.
Measure A and add to this chart
and “length chart” below
Inches mm
A
B1* 25*
E24.0 610
F30.8 782
G
Total A+B+E+F+G
Pin
to
Pin
A
IMPORTANT! If top foil
length is less than 5 5/8"
(143 mm), go to page 9.
*Add 1.12 " (29 mm)if using a 7304
halyard deflector.
A
C
D
E
Pin
to
Pin
B
G
F
G
Preassembly Top Foil Length

MKIV Ocean Unit 3 9
Preassembly Short Top Foil
Top foil length
from worksheet Actual top foil
Shorten bottom of
bottom foil by this
amount
in mm in mm in mm
UNIT 3
5 1/2 140 5 3/4 146 1/2 13
5127 5 3/4 146 3/4 19
4 1/2114 5 3/4 146 1 1/4 32
4100 5 3/4 146 1 3/4 44
31/289 5 3/4 146 2 1/4 57
376 5 3/4 146 2 3/4 70
21/264 5 3/4 146 31/483
251 5 3/4 146 3 3/495
11/238 5 3/4 146 41/4118
UNIT 3
Top foil length from worksheet:
7 7/8" - 6 5/8" (200 - 168 mm)
No change necessary.
UNIT 3
Top foil length from worksheet:
6 1/2" – 5 5/8" (165 – 143 mm)
Cut top trim cap to 4 1/2" (114 mm) as shown above.
Unit 3
Top foil length from worksheet:
5 1/2" - 11/2" (140 - 38 mm)
Actual Top Foil
6 1/2" (165 mm)
Do not cut top foil to length from worksheet. Cut top
foil to 6 1/2" (165 mm) and shorten trim cap
by 1 3/8" (35 mm) as shown at left. Shorten bottom foil
per chart below. Foil will be clamped in upper holes.
7 7/8"
(200 mm)
Cut 1 3/8" (35 mm)
off top trim cap
Cut-off Do not use.
6 1/2"
(165 mm)
UNIT 3
Top foil length from worksheet:
1" - 1/2" (25 – 13 mm)
Do not use short top foil. Use full length foil and
clamp foil higher in drum assembly.
Use one of the following special techniques for foils under 7 7/8" (200 mm) to ensure sufficient bearing surface for
foil in area of halyard swivel.
In this method only the upper holes
are used thus there is limited up/
down foil adjustment.
Cut-Offs
Do Not Use
Upper holes

10 MKIV Ocean Unit 3
Preassembly Confirm Foil Length
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" (25 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.
No halyard deflector - 1" (25 mm)
With halyard deflector 2 1/8" (54 mm)
If 7304 Halyard Deflector is used,
add 1 1/8" (29 mm)
1" (25 mm)
Confirm foil length by laying foils alongside stay with turn-
buckle components.
Pull stay out so it is straight. Attach Harken toggle to bot-
tom of stay. Make sure toggle straps are straight. Adjust
turnbuckle so that length of stay with Harken toggle will fit
boat. Turnbuckle should be one-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.