Flexistentialism » Scooter Stuff http://flexistentialist.org/blog Mon, 31 Oct 2011 03:34:43 +0000 en hourly 1 http://wordpress.org/?v=3.2.1 Big Babies http://flexistentialist.org/blog/archives/2005/10/04/big-babies/ http://flexistentialist.org/blog/archives/2005/10/04/big-babies/#comments Tue, 04 Oct 2005 23:39:03 +0000 Sam http://flexistentialist.org/wordpress/?p=438 Today was ‘tend to the whiney babies’ day. No, not actual babies, but big, hot, greasy babies that run really fast. Yes, cars and scooters! They demand care, and will act up if they don’t get it. Today my scooter was saying, “Waaah! Waaah! My coolant and brake fluid need to be flushed! Waah! I’m in danger of corroding my caliper seals! Waah!” Sympathetically, the Mercedes was saying, “Waaah! My rack tension is loose! Waah! I’m going to violently shake side to side because there isn’t sufficient tension dampening the injection system causing a stronger fire on a fore cylinder! Waah!” This all came just a few days after Madalene’s new Civic said, “Please give me new spark plugs and wires, and I’m gonna need my nappie (er, CV boot) changed soon! Oh, and my rear brakes are leaky!”

Damn them! The Mercedes was an easy fix, but the scooter required that I purchase some additional tools. One of my new tools was not functioning well (a vacuum pump), and I ended up spending several hours trying to get the cursed air out of the brake system. Fortunately, I eventually found success. As it was getting dark, I managed to finish up the coolant flush, which wasn’t nearly as difficult (though I did have to dremel a non-removable hose clamp off a hose).

I’m now greasy and tired, and still have more to do tommorow. Its ok, babies, daddy is here for you…

]]> http://flexistentialist.org/blog/archives/2005/10/04/big-babies/feed/ 5 Scooter Maintenance Articles http://flexistentialist.org/blog/archives/2003/10/28/scooter-maintenance-articles/ http://flexistentialist.org/blog/archives/2003/10/28/scooter-maintenance-articles/#comments Tue, 28 Oct 2003 06:08:47 +0000 Sam http://flexistentialist.org/wordpress/?p=342 I will be posting a slew of scooter maintenance articles over the next several days, and this post will serve as a directory for those posts, and something to link to.

The articles deal with maintenance and performance upgrades for the Aprilia SR50 DiTech and the Aprilia Mojito (Habana in Europe). They are both 50cc scooters, but the Mojito is air-cooled and has a carburetor, and the DiTech is liquid-cooled and has fuel injection. Both scooters are built on the Morini platform. However, even if you have a different scooter, it is likely that you will get some benefit from these articles. Many scooters are built on the Morini platform, and even scooters built on other platforms will have similar parts and arrangements. Modern scooter makes such as Vespa, Malaguti, Piaggio, Honda, Yamaha, Italjet, MBK and Benelli all have similar innards, and you can learn much from these articles.

These articles were all written by Scott (AKA “Scootnfast”:http://www.apriliaforum.com/forums/member.php?s=&action=getinfo&userid=1418 on the “ApriliaForum”:http://www.apriliaforum.com boards) as forum posts. I have (with Scott’s permission) taken the information and photos he posted, edited them for clarity and formatting, and posted them here, in order to preserve them and make them more accessible to non-forum goers.

Here are the articles currently posted. If the article isn’t linked yet, it means I haven’t finished putting it all together, check back for updates and additions:

* “CVT Basics”:http://www.flexistentialist.org/archives/2003/10/27/cvt_basics_const.shtml – Describes the basic operation of the CVT (Constant Variable Transmission) that is the automatic transmission for most modern scooters. It is a simple device, but it can be difficult to understand how the different parts, roller weights, variator pulleys, and contra springs all work together to provide you with twist-n-go ease. Any scooter driver should understand at least a bit about what is going on down there.
* “De-restricting an Aprilia Scooter, or Most Any Modern Scooter”:http://www.flexistentialist.org/archives/2003/10/28/derestricting_an.shtml – Most modern scooters come to you in a restricted state. They aren’t producing all the power they can be. This is usually done for legal reasons dealing with importing and registering of scooters, but the restrictions are easily undone, to give your scooter back its performance. The directions described are for an Aprilia Mojito and SR50 Ditech, but the techniques are applicable to nearly all modern scooters.
* Installing a Big Bore Kit on an Air-Cooled Mojito – This article describes the installation of a 70cc kit on an Aprilia Mojito, which is an air-cooled scooter based on the Morini engine. Techniques here will be applicable to nearly all air-cooled two-stroke engines.
* Installing a Big Bore Kit on a Liquid-Cooled SR50 DiTech – This article describes the installation of a 70cc kit on an Aprilia SR50 DiTech, a fuel injected, liquid-cooled version of the Morini engine. Techniques here can be used for other DiTech scooters (such as the Scarabeo DiTech), and other liquid-cooled engines.
* Installing New Final Drive Gears on an SR50 DiTech – This article describes the installation of new final drive gears on a DiTech. These instructions should help with the installation of gears on any Morini based scooter, and will give you an idea of what is involved in any final drive installation.

]]> http://flexistentialist.org/blog/archives/2003/10/28/scooter-maintenance-articles/feed/ 31 De-restricting an Aprilia Scooter (Or Most Any Modern Scooter) http://flexistentialist.org/blog/archives/2003/10/28/de-restricting-an-aprilia-scooter-or-most-any-modern-scooter/ http://flexistentialist.org/blog/archives/2003/10/28/de-restricting-an-aprilia-scooter-or-most-any-modern-scooter/#comments Tue, 28 Oct 2003 05:31:31 +0000 Sam http://flexistentialist.org/wordpress/?p=341 If you drive a modern automatic (twist-n-go) scooter, then it is likely that your scooter has been restricted to prevent it from reaching its full power. This is typically done to keep the power and speed down so that the vehicle can be registered under scooter or moped classifications that many states have. This classification means many scooter drivers do not need license plates, special licenses, or expensive registrations.

However, how much fun is it to have a restricted vehicle? Not much. So if you’d like to get the full power out of your ride, you can remove the restrictions yourself, and enjoy a vehicle operating at its full potential.

This article deals with derestricting a 2004 Aprilia Mojito 50 (known as the Habana in Europe) and mentions specific differences with the technique for the Aprilia SR50 DiTech, since these two scooters share the same drivetrain. However, the derestriction techniques described here work on most modern automatic scooters, with some variation between brands and models. This document was originally written as a thread on the “ApriliaForum”:http://www.apriliaforum.com by Scott (AKA “Scootnfast”:http://www.apriliaforum.com/forums/member.php?s=&action=getinfo&userid=1418) and all credit should go to him. He wrote the bulk of the document, and took the pictures. I am simply removing the info from the forum context, doing some editing for clarity and formatting, and putting it up for all to see (specifically Googlers).

For other articles available “check out the list”:http://www.flexistentialist.org/archives/2003/10/28/scooter_maintena.shtml or read on to continue this article.

How to de-restrict a scooter is one of the most common questions asked on the “ApriliaForum”:http://www.apriliaforum.com and in emails to myself and others. Hopefully this article will give you what you need to get into that scooter, and de-restrict it.

Let me start by letting you know some basics…

* If you tamper with the motor in any way to de-restrict it, some dealers will completely void your warranty. So make sure this is a sacrifice you are willing to make. If you mess up your scooter while wrenching it in your back yard, your dealer will help you out, but don’t expect too much sympathy.
* De-restricting your scooter may cause it to violate your State or Country’s laws concerning the scooter or moped classification. For instance, in Missouri, if your scooter makes over 3 horsepower or goes over 30MPH, then it needs to be registered as a motorcycle, and the operator needs to have a current motorcycle endorsement on their license. Many people don’t bother to do this, since the vehicle still looks the same as it did, and enforcement is very rare, but you should be aware of your local laws, and you must accept responsibility for your actions if you decide to break any of them!
* ALL bolts and socket head cap screws are in metric! Don’t try to work on your vehicle if you don’t have metric tools, you will just end up messing up the heads.
* This article describes the technique for a 2004 Aprilia Mojito. Much of the drive-train is the same on the Aprilia SR50 DiTech, and is very similar on the other Aprilia models. If you have another model than the one described here, just go slow, and make sure to note differences between your setup and this one.
* If your scooter is not an Aprilia, then this guide may still be of use. The Mojito uses the Morini engine, which means it shares many parts with other vehicles using the Morini, such as Suzuki Katana scooters. Also, while the engines are fairly different, most Minarelli engine scooters have a very similar setup in terms of restriction. This includes many Yamaha’s and Malaguti’s. Even Piaggio’s and modern Vespa’s have similar restrictions.

The Mojito has 4 restrictions on it. They include:

# A small washer in the variator.
# A jet restrictor in the carb.
# Two restrictors on the exhaust system, an inner flange restricting flow, and a resonator tube that impedes scavenging.

Most modern scooters have some combination (or all) of the above restrictions. To properly de-restrict a scooter, you must do all of the parts. If you only do half the job, you could actually damage the scooter. Ask your dealer, or other enthusiasts who own the same scooter as you, to find out exactly where your model is restricted.

The SR50 DiTech has only two restrictions, but one of them is different from most scooters. The washer in the variator is present (though it may not be on the ’03 DiTechs I have heard?), but it also has a restriction in the ECU, the computer that controls the fuel injection. This restriction MUST be removed by a dealer, since only they have the equipment to reprogram the ECU. The equipment takes the form of a Gameboy cartridge that plugs into your scooter and into the Gameboy, giving the dealer the ability to update your software. Many dealers will do this for free, some may charge for the labor (should only take a few minutes, really). The exhaust isn’t restricted per-say, but it should be replaced for best performance, along with installing lighter roller weights. Of course, that costs a bit of money.

Results for de-restricting these vehicles are as follows:

* Scott’s SR50 DiTech – Stock had decent acceleration, and a top speed of 40-45 MPH. After de-restricting (washer removal and re-mapping), I had a top end of 58 MPH, but had terrible acceleration, and a dead spot from 35-45 MPH. I put a Gianelli exhaust on, and a new Malossi Fly clutch. I used the 6.5 gram roller weights that came with the pipe, and I get 60MPH on level ground with great acceleration and no dead spot.
* Sam’s SR50 DiTech – After de-restriction, and the fitting of a Gianelli NRX exhaust and a Malossi Fly clutch, top speed is about 60MPH on level surface, with consistent acceleration through the entire range. After having troubles with a dead spot that surfaced at around 35-40MPH, I lightened the weights from 6.5g to 6.0g and installed a new White contra spring, which removed the dead spot and returned acceleration to its prime. Basically identical results to those found by Scott.
* Scott’s Mojito – Stock… Well it was a DOG!!! 30 MPH, 35 MPH downhill, with virtually no acceleration. After completing all 4 de-restrictions, a top speed of 47 MPH (verified), and really good acceleration… Everything else is still stock! The only thing I bought for it was a .8 mm jet ($10)!!! I have an Arrow Classic high performance exhaust for the Mojito also, but I recommend getting the Leo Vince pipe instead. With that on, I have even better acceleration, and a top end of about 52MPH flat out, and 55MPH down hill!!!

Just a few notes about working on your vehicle: Remember where every hose and cable you disconnect goes! This is very important. You might think you can remember each little screw and hose, but when it comes time to reassemble, its very easy to mistake a few hoses or screws and cause yourself a world of hurt. Do what I do. Make little drawings of everything as you go, and use little labels on pieces of tape to identify hoses and mark their locations. It sounds silly, but it will save you a lot of trouble, trust me!

Also, keep in mind that Scott and I are not mechanics, just interested scooter fanatics. When in doubt, take it to your dealer! However, now that all this prep work has been laid down, lets get into the de-restriction.

Removing the Variator Washer

First start by removing the socket head cap screws to remove the transmission cover on the left side of the scooter. Be careful of the gasket, my mojito had a gasket, but my DiTech didn’t. Ignore the ‘remove kick start’ in the photo below. I am used to working on motorcycles, where the kick start is actually attached to the crank and you have to remove it to get the cover off. But on these scooters, you DO NOT have to remove the kick-start. In fact, you do not need to remove the kick-start on any scooters to my knowledge.

This is what you should have removed. Keep track of those screws and the gasket. If your scooter does not have a gasket there, don’t worry. The DiTech’s do not have one.

OK, now you should be looking at the whole drive train. As you face the open transmission, the variator is on the left, and the clutch is on the right. To remove the nut on the variator, you need an impact wrench. If you try to use a regular wrench on the nut, then you will just rotate the pulley around, and not get anything done. There are special tools that let you block the piston in place, or grip the variator to hold it still, but the best solution is an impact wrench! There are both electric models and pneumatic models available, for reasonable prices. Investing in an impact wrench will make your scooter maintenance live much easier. Try “Harbor Freight Tools”:http://www.harborfreighttools.com if you live in the US.

Removing the nut on the clutch is also best done with an impact wrench, though you can also have a helper hold the rear brake down while you undo the nut with a regular wrench.

Once you have the variator off, you will notice a washer located between the two halfs of the pulley. This is a restriction! That little washer does not let the two halves come completely together, which prevents the scooter from going into its highest gearing. For a good explanation of the transmission to help understand why that washer does what it does, read the article “CVT Basics”:http://www.flexistentialist.org/archives/2003/10/27/cvt_basics_const.shtml. Removing it makes a big difference in top speed.

While we have the variator off, I will show you where the roller weights are located, they are in the back of the variator. You have to remove three screws to get to them. I left the little stamped cover off when I re-assembled everything. It is not needed, and I have heard that it can sometimes impede the variator from reaching its highest ratio.

Once you have it apart, this is what it will look like. If you want to go to a different weight, this is when you do it! If you are de-restricting a DiTech, you may wish to change rollers at this point. Many people find the stock rollers to be far too heavy, and have better performance with something in the 7.5g range. If you are adding a performance exhaust system like the Gianelli NRX, then use the roller weights they have provided. To get roller weights, check out the “ApriliaForum store”:http://apriliaforum.safeshopper.com.

After the washer has been removed, re-assemble the variator onto the crank shaft. Make sure the starter gear behind the variator is on the spline, and make sure the variator is all the way pushed to the back before tightening the bolt. The bolt must be impacted on, and be sure to use some Loc-Tite (use the Blue version, it is removable) on the bolt before tightening the nut. It will have a tendency to spin off, so LOCTITE IT!!!

OK, that is it for the variator / washer restriction!

Jet Restriction in the Carburetor

Now, lets go to the carburetor. Here, the main jet is a bit too small, and should be changed. I am not sure what the stock jet size is, but it is small. Get yourself a larger main jet. I went with the .8mm jet, with shipping it was about ten bucks. Give “AF1 Racing”:http://www.af1racing.com a call or email to find a new jet for your scooter.

The first step is removing the carb. You have to disconnect all the cables and hoses. Be careful when doing this, work in a clean enviroment. A little bit of dirt in the carb is a bad thing! Keep needles from the choke and throttle from touching anything. When the gas line is removed, stick a screw in it to keep gas from leaking.

This is how you take off the choke.

Once everthing has been disconnected, remove these screws to take off the carb.

The carb is going to be filled with gas, so be careful! No smoking, dummy! Lay a paper towel down and flip the carb over. Remove the two screws on the bottom and take off the bottom cover.

Use a clean flat-head screw driver to remove the jet. Simply screw in the new larger jet in its place and re-assemble carb. Bolt the carb back on and re-attach all the cables and hoses. When putting the throttle cable back in there is a channel and a key that has to line up. Turn it until it lines up and falls in all the way.

Now you can reassemble in the order you disassembled, and we can move on to the exhaust system.

Two Restrictions on the Exhaust System

There are actually 2 separate restrictions on the exhaust. I will be honest, it is a pain in the butt to do this. There is a lot of grinding and cutting involved. My honest opinion is don’t bother, buy a performance exhaust! It is well worth the money, saves you some time and the performance exhaust will give you even better performance. But for those of you on a tight budget, I went ahead and de-restricted mine just so I could take pics to show you how to do it. Make sure you read this entire section before beginning this project, just to make sure you want to get into it.

If you choose the route of a performance exhaust, go with something like the Leo Vinci ZX, or the Gianelli NRX, both of which are fine pipes. There are also some nice offerings by Arrow and Top Performances. Check out the “ApriliaForum store”:http://apriliaforum.safeshopper.com for pipes for your Aprilia scooter.

Start by removing your exhaust. Two bolts hold it to the engine, and three bolts hold it to the side of the frame. Remove them all, and carefully remove the exhaust. You will notice a flange with three bolts and a little pipe that comes off the side of the main pipe and just comes to an end. We need to grind the bolts off to get to an inner flange, and we have to cut off the little pipe that extends to the side.

Once you have ground off the bolt heads, you will be able to see the restrictor. You will notice a large pipe comming through the flange, but there is a smaller pipe welded inside it. You now have to cut off the small pipe behind the weld. Use a file to smooth out the burrs. Make sure you clean out all the chips before re-assembling with new bolts.

Now that little pipe that has to be cut off. The proper way to do this is to cut it off and re-weld it shut. But if you are like me and welderless, I just left enough pipe to crimp and fold it over. I put the end I cut off into my vise and closed it until the pipe came together. After that I took a pair of vise grips and bent the fold in half. Then I beat it with a hammer until it was completely closed. After that I took a grinder and smoothed it over. I guess some JB weld or some exhaust tape might work also. However you do it, it is important that there not be any leaks here, or your performance will suffer!

Now you need to re-assemble the exhaust. You are going to need some new bolts to replace the ones you cut off. I was able to buy the same thread bolts and put them through the nuts that were left welded to the other side of the flange. But if the nuts are messed up on the bolts from the weld, then you will need to grind the nuts off and use new nuts and bolts. Use some high temp black paint to paint over all those unsightly grinding marks you made! But it should look like this when you are done.

OK, all you have to do now is re-attach the exhaust to your scooter. Be sure to get the gasket between the pipe and the head back in its place. If the gasket isn’t very pristine looking, order another from your dealer and replace it. You don’t want any leaks there.

And that is it for de-restricting! Enjoy your scooter’s new found performance! Again, for parts, I highly recommend “AF1 Racing”:http://www.af1racing.com who runs the “ApriliaForum store”:http://apriliaforum.safeshopper.com for all your Aprilia needs. If you have a non-Aprilia scooter, give AF1 a call, as they will likely be able to help you out anyway! And of course, if you want to ask questions or just chat about Aprilias, the “ApriliaForum”:http://www.apriliaforum.com is a great place to go.

]]> http://flexistentialist.org/blog/archives/2003/10/28/de-restricting-an-aprilia-scooter-or-most-any-modern-scooter/feed/ 338 CVT Basics – Constant Variable Transmissions http://flexistentialist.org/blog/archives/2003/10/27/cvt-basics-constant-variable-transmissions/ http://flexistentialist.org/blog/archives/2003/10/27/cvt-basics-constant-variable-transmissions/#comments Mon, 27 Oct 2003 23:12:34 +0000 Sam http://flexistentialist.org/wordpress/?p=340 One thing people regularly wonder about is how a CVT (Constant Variable Transmission) works. CVTs are used mostly in scooters, like the 50cc Aprilia SR50 DiTech this document describes, but some larger scooters also use CVTs, and they are even being used on some Audis now! If you’ve ever been confused about that strange little transmission in your scooter, this should help clear things up a bit.

CVTs are quite simple in design, but since every part must work in concert with all the others, it can be difficult to visualize their operation, and understand how each part fits into the whole. The drawings are not to scale, but are meant to just give you a better idea about what is going on.

This document was originally written by Scott (AKA “Scootnfast”:http://www.apriliaforum.com/forums/member.php?s=&action=getinfo&userid=1418) on the “ApriliaForum”:http://www.apriliaforum.com website. I have done a bit of editing so that things make sense in a non-forum context, but all the photos and info are his, and have been reproduced with his permission.

For other articles available “check out the list”:http://www.flexistentialist.org/archives/2003/10/28/scooter_maintena.shtml or read on to continue this article.

People ask a lot about different roller weights, clutch springs, contra springs variators and belts. This is an attempt to put the effect these have on your CVT in simple terms.

The truth of the matter is, a new variator, springs, or weights WILL NOT increase your vehicles over all power! The power your vehicle produces depends on the engine, not the transmission.

What it does do is adjust your rate of acceleration, and at what RPM your motor runs at while it is accelerating, and at what speed the motor is reving when you reach the highest gear ratio available.

Now having said both of those things, the key is to have your motor running at the RPM where it creates the most horsepower consistently while accelerating. This value will be different for different engines. For the Aprilia SR50 DiTech used in this explanation, The max power is created between 8000 – 8500 RPMs. If you are accelerating at 5000 RPM’s or 9500 RPM’s, this will decrease your acceleration because your horsepower is not at it’s peak.

This goal is achieved through trial and error. Changing first your contra spring, and then trying different roller weights is how one might go about doing this.

In order for you to understand which way you need to go with weights and springs, you must first understand how the entire drive train works.

Lets start with the front pulley of the variator. This is where your roller weights and ramp plate are located. This image is a cross-section of the front pulley, showing the front half of the pulley, the belt, and the rollers sitting against the ramp plate. This is how the transmission looks when the engine is running at low RPMs.

Now as the RPM’s of the motor increase, the centrifugal force pushes the roller weights outward (number 1 in picture).

The roller weights push out and onto the angle plates surface. This causes the rear half of the pulley to move toward the front half of the pulley (number 2 in picture).

When the rear half of the pulley pushes to the front pulley, it forces the belt out to a higher gear ratio (number 3 in picture).

This is the basic operation of the front pulley. Faster engine speeds cause the belt to go outward.

If you are thinking about getting a new variator, let me first start by telling you that it will probably not have any effect on your over all top speed. What it will do is give you a more steady acceleration. The distance that the rear half of the pulley can travel pretty much remains the same. Meaning that it will only push the belt out as far as the stock variator will which results in the same high gear ratio as the stock variator. The key difference between the stock and performance variators is the angle on which the roller weights travel and the angle on the angle plate in the rear of the variator. This will only help give you a smoother, more constant acceleration.

Now as for the different weights for the rollers. It is really rather simple. The heavier the weight, the more force will be applied to the angle plate forcing the rear pulley half forward faster. If the roller weights are too heavy, it will force the gear into too high of a gear too fast.

I like to use a 10 speed bicycle as a comparison. From a dead start, if you are in 10th gear, it is very difficult to get going. But if you are in first gear, it is very easy to get moving. the same principle applies here. You want the weights to keep you in first gear, and as the RPM’s increase, it will gradually step the gears up until it reaches tenth gear.

If your roller weights are too light, then there will not be enough force to push the ramp plate out and the rear half forward. This will result in good acceleration, but a low top end. You will simply remain in a low gear for too long. As the engine speed finally gets moving enough to move the pulley forward and raise your gearing, you will be above the RPM of peak horsepower for the engine, and it will not have the power to get you moving.

This image is a side view of what the ratio looks like in low gear. You will see that the front pulley is small, and the rear pulley is large. This is like first gear of the 10 speed bike.

This image is what the gear ratio looks like when the roller weights are pushed out and the rear half of the pulley is forward. The belt is pushed out to a higher ratio. This is like tenth gear on the bicycle.

Now the other factor in this equation is the rear pulley. The rear pulley has a spring holding it together. This is your contra spring.

The front half of the pulley is also torque controlled. There are angled grooves that the pulley travels on. As torque is applied, this limits the belt from traveling in too quickly. Likewise, as you go up a hill and torque is applied to the pulley, it is supposed to force the pulley together giving you a lower gear ratio.

This image is what the rear pulley looks like at low rpm’s. The spring is forcing the two halves of the rear pulley together, holding belt outward, and keeping a low gearing. As torque is applied to the belt, the halves of the pulley begin to separate, pulling the belt inward, which raises your gearing. The stiffness of this spring determines how fast the pulley halves expand, and how strongly they return to their original shape when the torque is lowered again.

This image is what the rear pulley looks like at high rpm’s. Notice the spring has been compressed, and the belt has moved inward.

If your roller weights are giving you good acceleration, and a good top end, but when you approach a small hill the scooter slows drastically, this may be caused by having too light of a contra spring. The contra spring helps push the rear pulley back together when torque is applied to the rear pulley.

Say you are running good at say 50MPH, and you slow down to 35MPH. If you then try to accelerate, and you have hardly any acceleration, this can be caused by having too light of a contra spring. When you slow down, the spring is supposed to push the rear pulley together into a lower gear ratio. If the spring isn’t strong enough, the pulley will remain in a high gear, and then when you try to accelerate, there isn’t enough power to push you because you are in too high of a gear.

On the other hand, if your spring is too strong, then the roller weights may not be heavy enough to force the belt out all the way and into it’s highest gear ratio, and you won’t be able to reach your top speed.

If you go with a stiffer contra spring, you may need to go to a slightly heavier roller weight. Likewise, if you go to a softer spring, you may need to go to a lighter roller weight.

There is a very fine balance that you must achieve between the contra spring and your roller weights. This is only accomplished through trial and error.

If you are looking for different roller weights for your scooter, check with your dealer or do some web searching for your model of scooter.

The “ApriliaForum store”:http://apriliaforum.safeshopper.com (operated by the fine folks at “AF1 Racing”:http://www.af1racing.com) carries a variety of roller weights and contra springs for carbed Aprilia scooters and Aprilia DiTech scooters. Malossi springs are ordered by color. The white is the softest, red the stiffest, and yellow somewhere in between. If you are going to get a new spring, I recommend getting the red or yellow one. Starting stiff is good, and you can adjust your roller weights from there. The forum store also carries Malossi MultiVars, which are a fine replacement for your variator, as well as Malossi clutches.

Installation of a contra spring is fairly easy, and is described next. If you need to change roller weights, or get into the variator, read the De-restriction How-To for more information!

Changing the contra spring starts by removing the cover from the swing arm on your scooter. Then you remove the nut that holds your rear pulley and clutch assembly on. The nut can be difficult to remove, because the entire assembly will rotate as you try to turn the nut. One technique is to have a helper hold the rear brake down as you loosen the nut. Another way is to use an impact wrench, which can remove the nut on the front and rear pulleys without worrying about the part turning. They do this by ‘rattling’ as they turn, which can loosen a nut in fast spurts, before the pulley has a chance to rotate under your wrench. If you plan on working with your scooter very much, I highly recommend getting one. You can find electric ones (commonly used for removing the wheels of cars) for pretty cheap, or if you want to go more professional, you can find very nice pneumatic impact wrenches. The benefit of pneumatic is that once you have the setup (compressor, hoses, fittings, etc.) you can continue to add tools for relatively little expense.

Once the nut has been removed, remove the clutch bell housing and then pull the entire rear pulley and clutch off the axle.

Once the pulley has been removed, you have to remove the large nut on the side of the clutch. This can be rather difficult. The nut is on rather tight, and it is very difficult to hold the pulley while you loosen it. I used two large C clamps and a piece of rubber to give them grip to hold it down on my workbench while I removed the nut.

Be careful after you loosen it. The whole clutch is essentially spring loaded. The contra spring is pushing on the clutch. When the nut is fully removed, the clutch will shoot out at you. So be sure to hold it firmly when removing the bolt and be careful. When in doubt, wear safety glasses, and get a helper.

After the nut is removed, you can slip the assembly apart, change your spring and re-assemble. Compress the spring and tighten the nut back on. Use a drop of blue (removable) Loc-Tite to keep things together.

Thats it! I hope you understand a bit more about the CVT and how its parts work together. With some trial and error, you’ll be well on your way to maximum scooter performance.

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