it wil not improve peformance but will improve the top speed as its in there to stop the two halves of the variator coming together and gearing the bike up,somit will pull away exactly the same but have a 10mph increase approx on the top end.it will not ahrm it at all and abroad they do not even have this washer in them.incidentally did you know this mbk ovetto is the same machine as a yamaha neos yn 50.just with mbk badges on it and mbk come from france but they do not import them any longer.
adam bike doctor
February 2010