Fitting a variator, changing rollers or replacing the drive belt
January 19th, 2010
Fitting a variator or checking the condition of variator rollers is pretty easy in most cases, garages looking for work might contradict this but we think you ought to have a go yourself.
The procedure mentioned in this brief guide might assist you in some way and could help save you both time and money. The following steps also apply to changing your drive belt or checking its condition.
1. First of all you’ll need to remove the crank casing on the left hand side of your scooter; this is normally where the kickstart lever is visible. Make sure that when you remove all the bolts you remember their locations and don’t lose any. Gently separate the outer casing from the engine, don’t be alarmed if it feels like it won’t move, it’s usual for casing guides positioned at either side of the casing to seize, WD40 and a little persuasion should do the job.
2. Once inside you’ll see the variator assembly to the left and clutch assembly to the right, both units are held in place with a single nut that can be removed in the normal anti-clockwise fashion. One thing to point out is that due to your scooter being automatic, the variator and clutch assembly would simply spin in the direction you turn if using a spanner or socket wrench. A locking tool is therefore needed or alternatively an electric impact gun or the garage type compressor tool.
3. After selecting the tool of choice you now need to remove the crank nut, we recommend using a locking tool just because they’re cheap and possibly less damaging. This might be a good time to point out how useful it could be to draw a diagram that you can understand; this will allow you to re-assemble the parts in the exact same order they were removed without having to make an educated guess later on.
4. Remembering the order the parts were assembled, start taking them off the crankshaft until you reach the variator. If you’re replacing the original part with an aftermarket variator then take care in reading any fitting instructions making sure you adjust or replace the spacers described.
5. Re-assembling the unit is a reverse of the procedure you’ve just undertaken, the only difference being that some of the parts, for example the belt, might need some ‘jiggling’ to seat properly. Due to the clutch unit having a compression spring inside the main assembly it will be working its hardest to push the belt to the outer area which is very normal. If the position of the belt is ignored it will be difficult to assemble the variator and give the impression the drive belt is too short.
An easy way around this (especially if you were born with an extra hand) would be to push the drive belt down into the driven wheel assembly at the rear making sure the drive belt reaches the axle shaft. Due to the constant tension from the compression spring it is far easier to compress the inner wheel along with the outer clutch bell together; this will work against the compression spring making the recess in which the belt sits expand enabling the belt to appear longer.
Holding the belt in this position with that extra hand will make clearing the crankshaft easy and eliminate the possibility of tightening the fan pulley against the drive belt. You might notice the belt looking looser than before, this will quickly correct itself once the transmission has been used.
Once all the above steps have been completed, refit the crank side casing using the bolts you removed earlier then start your engine. Congratulations, you’ve just completed one of the most regular service jobs carried out on your scooter. Over time this procedure will save you money and reassure you that the job’s been done with the parts that you want.
Words: Chris Halliday
Photos: Paul Robinson