A Genoa Roller Furling System is used to furl a sailboat's headsail by rolling the sail around the stay. Modern furling systems count on a plastic or aluminum foil section to protect the cable or rod stay and the sail and allowing easier furling. There are furling systems for all types of preferences, but sometimes it can be difficult to identify all the parts needed for your boat.

For instance, in this article, we will help you to find all the parts needed to properly order one of the best furler units from a top brand such as Harken, the powerful MKIV (or its cruising version, MKIV Ocean), which will make the furling easier and will help you achieve a new sailing performance level.

1. Choose the Furler Type

Harken developed 2 MKIV jib furler models based on sailing style:

MKIV: For racers/performance cruising sailors looking for a strong, lightweight, and aerodynamic headsail furling unit. These free-rolling furlers make all the difference in headsail control by allowing racers and cruisers to quickly furl and reef from the safety of the cockpit while maintaining great sail shape and optimal speed.

MKIV Ocean: It is designed for cruisers and engineered for strength, longevity, and ease of use. MKIV Ocean furling systems offer the same quality as MKIV for racers but without features cruisers don’t need. They are made of hard-coat-anodized aluminum, UV-stabilized for durability and include multiple rows of Torlon® ball bearings to minimize friction and make pulling the furling line a less physical experience. The bearings require no lubrication for easy maintenance and feature a single groove foil.

2. Select the Unit Size

Once you determine the furler type based on your sailing style, you will now need to select the unit size based on 3 factors: typical boat length, headstay length, and clevis pin diameter.

Note:Click on your preferred part number to be redirected to the product.

3. Are any Additional Foils required?

If you cannot take out your headstay to measure, you can use the “I’’ and “J’’ rig dimensions from your boat to determine the length of the headstay.

If your current headstay is longer than the standard length, order additional foil and connector. One or two extra foils and connectors may be necessary in some cases. Each extra luff foil extrusion measures 2.13 m (7’).

SHOP HARKEN FOIL CONNECTORS SHOP HARKEN FOILS

4. Toggle and Link Plate

The way the furler is attached to the boat is by the clevis pin. Select the toggle assembly that works better for yours and choose between short or long link plates. Use a short toggle for maximum luff length.

Note:Click on your preferred part number to be redirected to the product.

Model	Unit	Harken Part No.	Description	Clevis pin
				mm.	in.
MKIV	1
		7311.20 1/2	Jaw/jaw	12.7	1/2
		7311.21 1/2	Long link plate w/toggle	12.7	1/2
		7311.21 5/8	Long link plate w/toggle	15.9	5/8
	2
		7311.20 5/8	Jaw/jaw	15.9	5/8
		7312.21 5/8	Long link plate w/toggle	15.9	5/8
		7312.21 3/4	Long link plate w/toggle	19.1	3/4
	3
		7413.20 3/4	Jaw/jaw w/short link plate	19.1	3/4
		7413.20 7/8	Jaw/jaw w/short link plate	22.2	7/8
		7313.21 3/4	Long link plate w/toggle	19.1	3/4
		7313.21 7/8	Long link plate w/toggle	22.2	7/8
	4
		7414.20 7/8	Jaw/jaw w/short link plate	22.2	7/8
		7414.20 1	Jaw/jaw w/short link plate	25.4	1
		7414.20 1 1/8	Jaw/jaw w/short link plate	28.6	1 1/8
MKIV OCEAN	1
		7311.20 1/2	Jaw/jaw	12.7	1/2
		7311.21 1/2	Long link plate w/toggle	12.7	1/2
		7311.21 5/8	Long link plate w/toggle	15.9	5/8
	2
		7311.20 5/8	Jaw/Jaw	15.9	5/8
		7312.21 5/8	Long link plate w/toggle	15.9	5/8
		7312.21 3/4	Long link plate w/toggle	19.1	3/4
	3
		7413.20 3/4	Jaw/jaw w/short link plates	19.1	3/4
		7413.20 7/8	Jaw/jaw w/short link plates	22.2	7/8
		7313.21 3/4	Long link plate w/toggle	19.1	3/4
		7313.21 7/8	Long link plate w/toggle	22.2	7/8
		7513.21 1	Long link plate w/toggle	25.4	1
		7513.21 1 1/8	Long link plate w/toggle	28.6	1 1/8
MKIV / MKIV Ocean	0
		7410.20 5/16	Eye/jaw (reversible)	7.9	5/16
		7410.20 3/8	Eye/jaw (reversible)	9.5	3/8
		7410.20 7/16	Eye/jaw (reversible)	11.1	7/16
	1
		7411.20 1/2	Eye/jaw (reversible)	12.7	1/2
		7311.20 5/8	Stud/Jaw*	15.9	5/8
	2
		7412.20 5/8	Eye/jaw (reversible)	15.9	5/8
		7312.20 3/4	Stud/Jaw**	19.1	3/4

*Thread ⌀ ⅝-18 LH

**Thread ⌀ ¾-16 LH

5. Lead Block Kit and Accessories

Harken recommend equipping every furling system with a ratchet lead block kit. We additionally include other accessories such as equipment for halyard management (halyard deflectors and restrainers) and racing hardware for faster sail changes.

Furling lead blocks maintain tension on the line so the unit furls smoothly and easily. The outboard assembly allows the line to travel outside of the stanchions, keeping the sidedecks clear. Inboard blocks assemblies are available for the bow pulpit, to handle two lines, for continuous line furlers, or for cutter-rigged boats with two furlers.

Harken offers halyard restrainers to be installed on the mast near the top of the foil to keep the line against the mast, preventing halyard wrap when furling. They also offer halyard deflectors to be installed on the stay above the foil system, preventing the jib halyard (and additional halyards (from wrapping around the foil); and stanchion-mount bases for Carbo and Classic blocks, as well prefeeders and snap shackles to facilitate fast sail changes.

For further details or any additional questions, please don't hesitate to contact us, our staff of sailing experts will be happy to assist you.

SHOP NOW HARKEN MKIV FURLERS HERE AT MAURIPRO SAILING!