PAUL DT125X

hi my dt125x 07 is making a funny nosie like a grinding nosie from the motor it's sounds fine when i start it and runs like a dream with no smoke but when i am going along at eny speed and eny gear when i come of the revs and pull in the clutch so im rolling along there is a on and off grinding nosie from the motor eny one now ?

what do you think

i got one from my yamaha shop £5.00 fited it today and wow only one tooth less but what a diferens the front lifts in 1 and 2 very happy top speed has droped by 10 mph but 0 to 60 has improved i would reconmend tis to every one with a dt125x if your not botherd about top speed

its only don 4000 miels so its not that worn

hi all i have a dt125x 07 can get 80mph 85 at a push but i never rely go past 50mph so i am going to change the sprockets front or back to get of the line farster and to pull the front up without reving the balls out of it . just need to now what's better front or back ? and how meny teeth to add or take off ? and where to get them from i have had a look on the web but no luck thanks your help will be very nice

thanks

IF I PUT A K&N ON MY BIKE WHAT WOLUD IT DO I HAVE A DEP AND RE JETTED IT WILL IT MAKE IT FARSTER MPH OR FARSTER OF THE LINE? THANS ALL