Loose spline on immovable variator.

[gregspeople250]

New guy here.  I've just completed the following service on my '06 People 250 with 13k Km's (I love this scoot'!).
Replaced engine and gearbox oil, valve adjustment (intake loose, exhaust tight), replaced drive belt & rollers, fuel and air filters, Iridium spark plug and brake fluid.
I noticed the spline on the immovable side of the variator was quite loose.  Is this normal?  Maybe this is one of the vibrations I feel at certain RPM's?  Is this a 'consumable' item that should be replaced at regular intervals?
While the scoot' was apart I installed a Trailtech Vapor gauge so I can more accurately read the temperature and speed and ended up with a tachometer and ambient temperature read out as well.  Really nice and easy to read.
Thanks!

[TechGuy]

I am not sure what you mean...

Can you point is out in this drawing?

[gregspeople250]

Sure, it's the part with the fan blades that is loose on the crankshaft spline.
Thanks!

[TechGuy]

I guess I am not understanding how it can be loose.



I took the image and added colored shapes.  For the purpose of this conversation, I will call the "DRIVE PULLEY FACE" in the pink box the "outside" pulley face and the "MOVABLE DRIVE FACE ASSEMBLY" in the blue/green circle inside pulley face.  The all caps are what the service guide calls them. Service guide 08 ( see http://tinyurl.com/2btjb4d) .

The outside pulley should be tight (torqued) to the end of the spline

Install the drive pulley face, washer and drive
face nut.
Hold the drive pulley with the universal holder
and tighten the drive face nut.
Torque: 88.2～98N-m

The inside pulley should be held in place by the belt and the outside pulley.  You can snug up the belt, into the rear pulleys. and the inside pulley will move some, but not much.

[art]

  It should not be loose. I have had this happen when re installing the spline and grooves were not lined up properly.  I had to take a small file to the output shaft to remove the burs before it would line up again.
  This will happen when useing an impact wrench. I now thread by hand before putting any pressure to it.

[gregspeople250]

It's the purple side and it's loose on the spline.  I'll replace it next time I'm in there for service.

[art]

  This may damage the spline on your output shaft of your crank beyond repair. You may want to chack it out asap.

[TechGuy]

Greg,

How can it be loose but the scoot still motor correctly?  The outer pulley is torqued to the end of the shaft.  If it is loose, it is spinning / grinding / machining itself and it will fail. Either the nut will come loose or the pulley will fail.  If the pulley were to seize against the body of the CVT case or the spline shaft, the bike's engine could eat itself or come to an immediate stop. I could be wrong but I would hate to hear the worst happened.

It might be worth the time to have a professional look at it.  $100 today may save you a new bike tomorrow.

[gregspeople250]

The pulley was loose on the spline BEFORE I tightened the nut.  It's now tight, but there's a good chance it's working slowly and wearing more.  The pulley is aluminum and the crankshaft is steel.  The pulley appears to be designed to be a 'sacrificial' part during wear.

[TechGuy]

ohhhhhh....

You opened up the CVT and found a nut loose and you torqued it to the correct torque amount and the damage was minor, it should be fine. It should not sacrifice itself as part of normal wear. In a failure, yes, it should fail first and be the sacrificial part. I have heard the nut in some brands is considered a one time use part but it it is not listed as being so in the Kymco catalog.  Of the nut were over torqued, it may be out of spec and could be replaced. If it were over torqued, it may no stay torqued on to the end of the spline as the metal in bolt has been stretched past its limit and cannot stay tight,  Kind of like your leather shoes that were stretched by getting wet and worn for a long time, they are never the same again and cannot be fixed, only replaced.  It might be cheap insurance to replace that nut.  it can't be too much.
I just looked

90201-KR8       SKU: 90201-KR8-7520-M1
NUT FLANGE 14MM    1    $3.39    Add to Cart

[gregspeople250]

I meant that the spline was already loose when I removed it when I took the very tight nut off. 
I found that the spline was loose when I put it back on after replacing the belt and rollers.  Sorry for the confusion.
I think I'll just replace the pulley half when I'm in there next or if any new vibrations start.