Hey, i recently bought an rm 125 dirt bike, when ii bought it, the gears switched good and worked fine, i decided to change the oil and filled the crankcase with belray 80w gear oil 750ml, after the oil change, i noticed it takes 2 clicks to switch into 4th and sometimes 5th and it takes about 6 shifts down to get from 6th gear to 1st, also when i ride, sometimes, it dosnt shift into 5th gear all the way. For example, when im riding fast i switch from 4th up into 5th and then it revs high and after like 2 seconds it goes into gear, this happens rarely and i think its because im not shifting all the way in, i have no idea what the problem can be and it only started happening after i changed the oil, plz reply with suggestions