Step by step variator removal/installation guide. Scooter used is a Vento 50cc, but the procedure is basically the same on most other CVT scooters

Estimated time: 1-3 hours

Installing an adjustable variator of any kind will enable you to tune the way the scooter shifts and it will allow you to optimize the variator for your weight and the riding conditions.

The first step is to remove the 8mm screws from the transmission casing (it has the kickstand attached to it). Note, you do not need to remove the phillps head screws, just the 8mm bolts. The transmission casing is depicted below.


After you have removed all the bolts around the outside as well as the long bolt in the middle (blocked from view by the kickstand) you can start pulling the case off. There are some bushings on either side of the case, you may have to wiggle it a little bit by the kickstand to rock them out so the case will pop off. You can also use a flathead screwdriver to gently pry the case off, but you will probably mess up the paper gasket. It's just as easy and safer to rock it till it pops off.


Here is a picture of one of the bushings towards the rear of my trans cover. Look in the upper right corner, see it sticking out?


After you pull the case cover off you will see two pulleys with a belt running in between them. The front pulley is your variator, the rear pulley is the clutch and bell. The variator controls the gear ratio of the belt by pulling apart and allowing the belt to slip down further and further as your speed increases (increasing the gear ratio). The outer part of the front pulley has fins to cool the inside of the casing when it's all buttoned up. The inner part of the front pulley is the variator and will resemble the part you are going to install. The rod that the front pulley is on is the crankshaft.

The hard part now is getting the variator to hold still while you use a socket wrench to loosen the outer bolt that holds everything together. I have found two methods that work. You can use a carefully placed pipe wrench, or you can go out and get yourself an electric impact wrench (which you will HAVE to have if you ever decide to do the clutch, and is handy to have around for other tasks as well). I have an antique pipe wrench that does the job. If you do it this way, make sure you don't put the pipe on the cooling fins, they are brittle and will snap in a second. Place the wrench on the outer pulley half, on the rounded part, try not to use so much force that you scuff it terribly. It may take some work to get it properly placed and on there tight enough that the pulley doesn't spin.

After you get the nut off, you will be able to just slide the rest of the parts straight off of the shaft.

First you need to remove the outer pulley half and the woodruff key.


Next you have to pull the outer part of the variator off. When you remove this part, there are six round weights that will probably come tumbling out. Save them so you can put everything that you replace up so you have a spare.


Now the only thing left is the inner part of the variator, it slides right off, there are three plastic vibration dampers to reduce noise and vibration where this part comes in contact with the outer variator housing. Pull it off and put everything with the original variator, put it in the box the replacement variator came in if you like.


Now we have pulled everything off. If there is any rust or dirt at the base of the shaft you can clean it off. It might also be a good idea to apply a little grease while you've got everything pulled apart.

WARNING
This mod could have adverse effects on roller and belt wear!
Please buy some high quality roller weights and bushings before doing this modification. Since this was written, I've also read that it may be a better to leave 1/4" sticking out rather than grinding it all the way down, but if one post is larger than the others it could result in belt wear.

If you have bought a Technomoto variator it can be modified a little bit to give you a better top end. There are three pegs sticking out past the rim that prevent the variator from letting the belt slide all the way down. This is good if you are running with a 50cc (stock) top end and you haven't installed a 70cc kit. You don't want the belt to slide all the way down because the bike will get out of the powerband and you won't be able to maintain speed going uphill as well (in other words, the 50cc or stock engine does not have quite the torque to drive the scooter properly if you do this modification). Now with all that said, all you have to do is take your shiny new variator to a grinder and grind those three pegs flat with the rim. Make sure it is flat with the rim and not below it, you wouldn't want to cause excess wear on the plastic vibration/noise dampers. You can also use a dremel. Try not to have any sharp edges on the inside walls if possible, but don't go overboard with the grinding. I would defiantly use some light grit sandpaper just to make sure that the edges are smooth. If not you could cause wear to the vibration dampers (which could cause it to lock up in high gear).

Now you need to pick the weights that you want to use, my variator came with three different types of weights. I initially installed the medium (grey/gunmetal) weights but found that the lighter weights (silver) worked better for me. Pick your weights and place them in the plastic cases. If possible, I would recommend that you don�t use the stock roller weights or vibration dampers. They are low quality, wear out quickly, and all of the weights are heavier than what comes in the Triton (4.0-4.5gm). Even using the lightest weights that came with my kit, I had a slower takeoff than the stock variator, until I got a Malossi weight/damper kit (3.5gm).


Now place all the weights in the outer variator housing as shown below.


Place the plastic vibration/noise dampers on the inner part of the variator, they will slide off pretty easily so be ready to put the inner piece with the rest of the variator assembly you have put together.


Next, hold the inner piece and the outer piece together so the roller weights don't pop out, and then get the metal cylinder that came with the kit and slide it into the outer variator housing.


To replace the belt, push the clutch pulley apart by grasping the clutch bell and the outer pulley and pulling them together (rotating it while pulling them together may help). Once you have the clutch fully depressed, slide the belt all the way to the center from the rear of the shaft. You should be able to pull the belt towards the variator so it is positioned all the way down on the little shaft, then release the clutch and the belt should hold it apart by itself. Now slide the other end of the belt over the variator, like you would a bicycle chain, rotate the variator and roll the belt on. Once you have the belt on, roll the rear pulley so the clutch releases and the belt tightens up so you can put the case back on.

Now get the case, line up the bushings, and gently tap it into place. Replace all the 8mm bolts, remember that the long one goes in the center. Some of the bolts are longer than the others, just look where you are putting them, they shouldn't protrude from the opposite side when they are tightened down.

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