EPI Tech Tips/FAQ's

Q. What is the benefit of an EPI clutch kit?
A. An EPI clutch kit can do several things for you. On a stock machine it will help your CVT clutches operate more efficiently which can result in quicker acceleration, reduced belt heat, longer belt life, and improved backshifting characteristics. If you've modified your machine - even just adding oversize tires, you have changed the CVT clutch calibrations. An EPI clutch kit will bring the calibrations back to an efficient level to work correctly with your modifications.

Q. My machine is completely stock. Do I still need a Clutch Kit?
A. Clutch Kits for stock machines can actually be the most challenging to develop. Many stock machines are clutched very well from the factory for general use. We try several different calibrations on all stock machines and look for reduced belt temps, quicker acceleration and crisper backshifting. On some stock machines we can improve all these areas while on others we may only be able to affect a single area of concern. Each machine is different, some benefit more than others in stock form.

Q. I've modified my motor, exhaust, tires… do I need a clutch kit?
A. Absolutely! These are the applications we like the most because your stock clutching needs help as you change these things on your machine. If you change the power output of your motor or add more resistance by going to larger, more aggressive tires you need to also change your CVT calibration. The stock clutching calibration is designed for stock motor output and stock size tires. Any changes to these areas result in a loss of power transfer through the CVT system. Recalibrating your clutches will recover the losses. We've tested many machines with aftermarket intake/exhaust systems and over-sized tires so we probably have your kit already. Some of the more extremely modified machines may require a bit of extra tuning to get the results you want.

Q. What is "backshifting" and why do I care about it?
A. A CVT system's ability to "backshift" is critical to keeping your machine's engine in its powerband while you're riding it. A strong backshift is what gives you crisp throttle response when you're on and off the throttle. As you blast through a turn and hit the throttle, you want your engine to snap right up to the sweet spot in its powerband so it's pulling hard immediately. Poor backshifting is characterized by a lag in throttle response.

Q. You have several different types of Clutch Kits, which kit do I need for my riding style?
A. EPI designs Clutch Kits for different applications based on riding style and modifications that owners make to their machine such as power increases, oversize tires and weight-adding accessories. Read through the descriptions on our website to better understand what each kit is designed to do, then give us a call at 218-829-6036 if you still need help deciding.

Q. Will a clutch kit affect my top speed?
A. We get asked this question daily and the answer is a clear maybe! Actually, the calibration components of a CVT system work to control the "rate of shift" of the system and have very little effect on top speed. Our clutch kits are designed to use the power from the engine to shift the clutches as quickly as possible and get you to your top speed quicker. Once your clutches are done shifting, your top speed is controlled by gearing, tire size and in some cases the ECU. The instances where a clutch kit will lower your top speed are when you have increased tire size and specifically want a clutch kit that reduces belt slip and gives you a lot of low-end torque for deep mud riding or rock crawling.

Q. Why does it matter what elevation I'm in when ordering a clutch kit?
A. First, let's clarify your question… it doesn't matter at all what elevation you are in when ORDERING a kit, it matters what elevation you will actually be RIDING in. Yep, we know we're funny…. OK seriously, As you go up in elevation, engines make less power due to the air being less dense. Everybody knows, you gotta have oxygen to make fire! We adjust the components in the kit to the elevation you ride at so your machine runs the correct rpm. To find your elevation, visit www.earthtools.org

Q. My machine has a "starter clutch" and I'd rather not mess with it. Can't I just skip installing those springs?
A. We strongly recommend installing the starter clutch (also known as a wet clutch) springs that might be included in your clutch kit. They are included for a reason. The starter clutch controls your stall or engagement RPM. If your kit includes these small springs then the kit was designed to work best with them installed. What commonly happens is someone skips the installation of them and is less than satisfied with the low-end performance of their newly clutched machine. In most cases the motor needs the higher stall to come into its powerband quicker and work properly with the other components of the clutch kit. If you're uncomfortable installing them, contact your dealer and have them do the work. It's probably time for an oil change anyway!

Q. I can't find my machine listed, does that mean you don't have a clutch kit for it?
We evaluate every machine to see if it can benefit from a clutch kit. Some machines will see increases in acceleration, some have belt slip problems that our kits correct. Some machines perform great in stock form and only benefit from a kit if modifications are made such as over-sized tires. If we can't make it perform better we don't offer a kit for that application.

Q. What components will come in my clutch kit?
A. Every machine and application can be different. The kit will contain what we've found is necessary to achieve the best performance possible. Some will include components such as weights, springs and helix while others may only be a spring kit.

Q. Can I install a clutch kit myself?
A. Each machine requires different levels of abilities and tools to properly install a clutch kit. EPI always recommends having an authorized dealer/mechanic perform the installation. Installation instructions are included with each kit.

Q. Is there a right and wrong direction to run a CVT belt?
A. Some belts come with an arrow printed on them to show the correctly installed direction and others simply suggest that you install the belt so you can read the writing on it. The bottom line is that the belt can run in either direction AS LONG AS you always run it the same way for the life of the belt. It needs to always run in the direction it ran when installed new.

Q. I'm looking at your wheelshaft charts - what is included with the halfshaft?
A. Our halfshafts include the outer CV joint only - you will need to reuse your inner CV joint.

Q. You have regular CV Boots and "Extreme Cold" CV Boots - what is the difference?
A. Our regular CV Boots are custom-fit for each machine and in most cases the best replacement part for everyone. Our "Extreme Cold" application CV Boots are a universal fit boot that is made of a much more pliable rubber that stays very flexible in extremely cold climates. We've found that in applications where a customer has had previous trouble with cracking boots due to extreme cold, these boots perform very well.

Still can't find the answer to your question? Call our Technical Support Department at 218-829-6036 Mon-Fri 8am-5pm.