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There’s one area in which modern fishing kayak manufacturers are all vying for supremacy: the respective realms of their pedal drive systems.

Some are made with automatic kick-up fins, as in the case of the Hobie MirageDrive. Others are capable of full power in forward and reverse. Some can even produce thrust that can be vectored, producing pinpoint, precise controls.

Others, like the Jackson Knarr’s Flex Drive Mark IV, are made with propellers. Here’s a high level view of what to expect.

General Observations of the Flex Drive Mark IV

Jackson’s Flex Drive Mark IV is quieter, faster, and more powerful than ever before. It features a design with a retractor cable housed entirely within the daggerboard, making the drive unit easily retractable on contact with an underwater obstacle, preventing damage to the system.

It also offers three positions - full retracted, for landing and launching, a half-position, for partial power, and a fully engaged position for maximum power in open water.

The design of the hull and drive system also gives the operator access to the prop, through a window at the base of the hull, giving you the flexibility to clear line or debris that may have become wrapped around the prop during use.

The upper and lower units of the drive system can also be easily connected and disconnected, for transport or maintenance purposes.

The design of the drive system also completely encloses most of the gears in a permanently sealed compartment full of oil, making it effectively maintenance free. By working with experts in the bike industry, Jackson’s engineers were able to devise a belt-driven system with a 1:12 gear ratio - meaning that for every complete revolution of the pedals, the prop will complete 12 revolutions, for a hitherto unheard or mechanical advantage.

The pitch of the prop is also more aggressive, resulting in more power, and is capable of full power in reverse, offering you better control over your Jackson Knarr.

One last thing: the designers are Jackson included a short gear track on the top of the Flex Drive Mark IV’s upper unit, making it possible to mount fishing kayak accessories, should you so choose.

Retracting the Prop/Changing the Shear Pin

Raising the lowering the prop (lower unit) of the Flex Drive Mark IV is a cinch thanks to its simplistic, user-friendly design.

To raise the prop fully so that it may be accessed through the cockpit, lower the lever on the upper drive unit fully.

To lower the prop fully so that the FD Mark IV can operate under full power, raise the lever completely. Verify that the daggerboard has descended fully, then turn the cranks to confirm it is operating properly.

The FD Mark IV is designed with a prop shear pin that protects the prop in the event of a sharp strike. If that occurs, the shear pin is designed to break, protecting the prop, the belt, and the rest of the drive unit.

To replace the shear pin, loosen the prop screw using a 3mm hex key, then remove the prop, remove the black plastic sleeve from the prop shaft, remove and replace the shear pin, and reverse the steps mentioned here to reassemble.

Removing the Flex Drive Unit

Removing the upper flex drive unit is also easy. Simply loosen the thumb screws on the ears of the upper system that secure them, then lift the upper unit off. The ability to remove the upper unit makes it easier to store it securely during long periods in storage, as well as for transportation and maintenance.

Basic Maintenance Considerations

While the Jackson Knarr’s FD drive system is designed to require minimal maintenance, giving it a little TLC after every venture on the water will keep it cranking for longer.

The simplest way to keep your Jackson Knarr’s FD Mark IV in good working order is to spray it off with freshwater after every trip out. While the gears are sealed, you should always clean it after use in saltwater.

Also, you should periodically remove the prop and check underneath it for accumulation of sand, debris or salt deposits. Clean gently and replace the prop before going back on the water.

The only other maintenance your FD Mark IV will require is belt tensioning, but do not attempt to disassemble the upper drive unit yourself. Contact your dealer or Jackson’s customer service for assistance.

Want More Information on the Jackson Knarr?

Still thinking a Jackson Knarr may be the fishing kayak for you? It very well might be, and the FD Mark IV is only one of its selling points.

It is geared for fishing, with plenty of room for storage, gear tracks for accessorization, and on top of that, it’s extremely stable.

For more information on the Jackson Knarr, see our listing page or get in touch with our customer service team at 512-229-0560. We would be more than happy to help.