What is it?
The z-Start Pro Clutch is a retrofit automatic clutch for off-road motorcycles and ATVs. It works using centrifugal force to automatically and smoothly engage the clutch just by using the throttle. The z-Start Pro manages the clutch function so the rider can focus on riding and having more fun.
The z-Start Pro is based on the same technology as Rekluse’s industry leading, patented z-Start Clutch and provides all the same riding benefits plus some additional unique benefits. The z-Start Pro provides stock-like clutch lever feel, improved override at all RPMs, simpler installation and reduced maintenance. For more information on the differences between the z-Start and z-Start Pro refer to section above, “Why Go Pro.”
What is included with the z-Start Pro Clutch?
There are two main portions of the z-Start Pro: a billet aluminum center clutch and the clutch assembly. The billet aluminum center clutch replaces the stock center clutch. The clutch assembly consists of the lower assembly, pressure plate and top plate. The lower assembly simply snaps into the Rekluse center clutch. The ball-ramp pressure plate with balls and a top plate then mount to the lower assembly. The z-Start Pro also includes custom steel drive plates to interface to the center clutch but utilizes standard OEM friction plates (Friction plates are not included in the kit). Some models may include a slightly thicker gasket to provide some additional clearance for the z-Start Pro. Everything except basic tools is provided in the kit to complete the installation.
What is the z-Start Pro made from?
The z-Start Pro Clutch is made from the highest quality billet 6061-T6 aluminum and billet 4140 steel, precision CNC-machined to tolerances of .001″ (that’s one one-thousandth of an inch). The center clutch and pressure plate are hard anodized for additional durability. The top plate sent through a final nitrating process to increase the surface that the 7/16” steel balls will run against.
How does it work?
The z-Start Pro Clutch is a centrifugal clutch that uses ball bearings to engage the clutch. The clutch provides a pressure plate with ball ramps. At idle the balls are at the bottom of the ramps and the pressure plate is disengaged. As the rider increases RPM, the balls move out the ramps, push on the Rekluse top plate and force the pressure plate into the clutch pack engaging the clutch. As RPMs build, the balls continue to move out fully engaging the clutch. When engine RPM’s are reduced the balls drop back down the ramps and the clutch disengages. The take-off is smooth as if you had perfectly feathered the clutch every time. The disengagement is quick, eliminating stalls.
At what RPM does the z-Start Pro Clutch engage?
The z-Start Pro is fully adjustable so the rider can set the engagement RPM. Springs are used to provide back pressure to the clutch and disengage it at idle. It takes a certain amount of force to overcome the springs and engage the clutch. By changing springs and spring compression rates, the rider can easily set the engagement RPM. Three sets of springs are provided such that a low, medium, and high engagement RPM can be set.
Additionally, the engagement rate of the z-Start Pro can be adjusted. The engagement rate is how quickly the clutch fully clamps the clutch pack. The z-Start Pro has two engagement rate settings – hard and soft. Use all 27 7/16” steel balls for a hard engagement, remove 3 balls and use only 24 for a soft engagement. The 7/16 ball bearings are larger than those used in the z-Start so hard engagement can be achieved without having to add any tungsten carbide balls.
Does the z-Start Pro require me to modify my existing clutch parts?
No. The z-Start Pro simply replaces your stock center clutch and pressure plate. No need to take apart the right side of your engine to get the whole clutch out. No need to send your parts away for permanent modification or to modify your existing clutch parts. With the Rekluse z-Start Pro, you can always return any bike to a stock configuration.
Can the clutch lever still be used?
The z-Start Pro is provided in a semi-automatic mode. A special spring and washer hold the stock throw-out to keep the lever taut when the bike is off or at idle. A unique benefit of the z-Start Pro is that it maintains a stock clutch lever feel and can be fully overridden at any RPM.
Does the z-Start Pro need a Rekluse Perch Adjuster?
No, the Rekluse Perch Adjuster is not recommended with the z-Start Pro. The z-Start Pro is set so that it utilizes the stock lever and cable such that the clutch override is very close to stock clutch lever feel.
How difficult is the z-Start Pro to install?
Riders who regularly perform maintenance on their clutch components can easily install a z-Start Pro Clutch. Most people will spend 30 to 45 minutes to read through the manual completely and carefully install the z-Start Pro. After the first installation, subsequent installations can be completed in 15 to 20 minutes.
Why does the z-Start Pro include a new center clutch?
The Rekluse Center Clutch is one of the key design elements of the z-Start Pro. The Rekluse Center Clutch provides significant benefits over the stock cast aluminum center clutch:
Fast and simple mounting of the z-Start Pro lower assembly by simply snapping it in with a snap ring – no more mounting shims
Improved drive plate design utilizes a new drive plate tooth profile to reduce wear on the center clutch
A replaceable, steel drive plate at bottom of the clutch pack reduces friction disk wear on the center clutch
Precision CNC-machined from solid 6061 T-6 aluminum bar with a hard-anodized coating
Reduced “run-out” and improved “parallelism” means smoother engagement of clutch components
Hard anodization significantly improves component life and reduces oil contamination
Will the z-Start Pro wear my clutch plates faster?
That depends on how you use or abuse the z-Start Pro Clutch. With the z-Start Pro, you will find that you are able to ride smoothly in one or even two gears higher than you normally ride. However, riding uphill, in 4th gear at 10mph for any extended period of time will cause significant clutch slipping, accelerate clutch plate wear and possibly damage your engine. When riding with any automatic clutch, it is important to select the right gear for the situation. In general, it is safe to ride one gear higher than the riding conditions dictate for short periods of time. That being said, when used properly the z-Start Pro should allow for clutch plate life equal to or better than a stock clutch.
What kind of maintenance does the z-Start Pro require?
The z-Start Pro Clutch is designed to work with a specific ‘installed gap”. The installed gap is the distance between the pressure plate and clutch pack when the bike is off. The installed gap is based on the distance that the balls rise in the ball ramps as the pressure plate is engaged. If the installed gap is too small, the pressure plate is too close and will cause the bike to drag at idle. If the installed gap is too large, the pressure plate cannot fully clamp the clutch pack and the clutch will slip excessively.
In order for proper operation and to maintain the life of the clutch pack, the installed gap must be kept in the prescribed range. Initially, the installed gap must be checked after breaking in the z-Start Pro Clutch for twenty minutes. As clutch wear occurs, the installed gap needs to be checked at regular intervals. Rekluse recommends riders check the installed gap after every 30 to 50 hours of riding.
How much weight does the z-Start Pro Clutch add to my bike?
Installing the z-Start Pro Clutch adds less than 15 ounces of rotating mass in the clutch. Keep in mind that the clutch spins at approximately 1/3 engine speed so flywheel effect of the z-Start Pro is minimal.
What if I have problems?
What kind of warranty does the z-Start Pro come with?
The z-Start Pro Clutch is backed by a 1-year warranty from defects in material or workmanship on all Rekluse-manufactured parts. The z-Start Pro Clutch also includes a 30-day money back guarantee. If for any reason you are unhappy with how the z-Start Pro Clutch performs in the first 30 days of use, simply contact Rekluse or our dealer for a return authorization and we will gladly refund your purchase.
