The Integral Bow Furling Unit appears to be made by Allen Brothers (Part No. A4904LZ). Its list price is in the order of £227 (Jan 2010). At that price it is worth spending a little effort on good servicing.

Servicing a sticky Furler unit or replacing a broken furling line
A poorly maintained furler can stick or jam, usually at critical moments.  The maintenance is relatively straightforward and if done annually will extend the life of the furler unit. The furling line  (3mm purple 16 plait) rarely breaks but if it does the following guidance will be useful when replacing the line.

The furler unit is the large black drum like object mounted in the bow of the dinghy (see above). The actual furler mechanism is sited in the centre of the unit and can be easily removed from the furler unit for cleaning without the need to remove the entire furler unit.

Remove the clevis pin and securing ring from the furler unit, and store safely. Slide your fingers around the top of the black gennaker chute canvas as it folds under the furler unit to release the velcro fastening (see below left). Pull the top of the chute clear to expose the screws at the centre top of the furler unit (below right).

Uncleat and slacken the furling line. Undo the two screws on the top of the furler unit, taking care not to lose either the screws or their washers. The furler mechanism will drop out of the bottom of the main furler unit with the line attached. If required slacken off the two large fastening machine screws at each end of the main furler unit. This will allow the main furler unit to be twisted to give better access to the mechanism. Withdraw the furler mechanism.  Undo the stopper knot in the end of the furling line and pull the line out of the furling mechanism.

Wash the mechanism under running water, spinning it to remove grit and mud etc. When fully dry spray the moving parts with silicon lubricant, spinning it freely as you do so to ensure a good penetration of the lubricant.

Now turn your attention to the through deck block in the  furler unit. This is the block (pulley) around which the furling line travels as it enters the furling unit. On my dinghy this was jammed fast.  It is a rivetted unit and therefore not easy to remove. To free my sheave I threaded a single piece of plastic sheathed electrical wire right around the jammed sheave and then used the wire to grip the sheave and spin it.  After a couple of tries the jammed sheave started to move. Spraying it with silicon lubricant improved its performance but it still did not run as freely as is needed. If anyone has a better solution please let me know!

To finish, thread the furling line through the centre hole in the mechanism and tie in a small stopper knot. Tighten the stopper knot and bed it securely in the furling mechanism. Make sure the end of the knot does not foul anything. Replace the furler mechanism into the furler unit and wind in the furling line.

Replace the two securing self tapping screws but take care not to cut another thread. Initially turn the screws backwards until they locate in the previously cut threads and tighten smoothly. If they resist turning you may not have located the correct thread. Try relocating them. Replace the gennaker chute cover and the clevis pin and ring.

Finally ensure that the furler unit is twisted in such a fashion that the furler mechanism is in exact alignment with the jib wire when it is rigged and tight. If the furler mechanism is not in exact alignment the mechanism will be pulled awkwardly by the Jib wire, will wear unevenly and will not function as well as it should.

Most dinghies have the painter tied around the furler unit. Check periodically that the painter has not twisted the furler unit out of alignment with the jib wire. If so loosen the two large machine screws securing the furler unit into the bow, correct the alignment and re tighten.